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Northwest Natural Company

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Employees 1001-5000
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FY2017 Annual Report · Northwest Natural Company
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2017 ANNUAL REPORT

GROWTH 
SUSTAINABILITY 
INNOVATION

NW NATURAL 2017 ANNUAL REPORT

With an unwavering commitment to our customers and a clear-eyed focus
on the future, 2017 was a pivotal year for NW Natural.

We welcomed new customers at the fastest rate in a decade; we made 
progress on an important expansion project; we continued to invest in our
distribution system— one of the most modern in the nation; we announced 
plans to expand into the water utility sector; and once again, our customers
rewarded us with high satisfaction ratings.  

For nearly 160 years, leadership has been a hallmark of NW Natural’s 
success—in our industry, in our region and in the communities we serve.
That, coupled with innovation, has made us resilient in a changing world.

But leadership and progress require balancing interests, and, at times, 
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of our Gill Ranch storage facility in California. Ultimately, we determined that
Gill Ranch is no longer central to our broader utility strategy, which is focused
on providing stable, regulated earnings growth for shareholders. 

Going forward, we will continue pursuing all strategic options to maximize its 
value, as we remain focused on operating the facility safely and serving our
current customers.

Financially in 2017, we reported a loss of $1.94 per share compared to 
(cid:72)(cid:68)(cid:85)(cid:81)(cid:76)(cid:81)(cid:74)(cid:86)(cid:3)(cid:82)(cid:73)(cid:3)(cid:7)(cid:21)(cid:17)(cid:20)(cid:21)(cid:3)(cid:83)(cid:72)(cid:85)(cid:3)(cid:86)(cid:75)(cid:68)(cid:85)(cid:72)(cid:3)(cid:73)(cid:82)(cid:85)(cid:3)(cid:21)(cid:19)(cid:20)(cid:25)(cid:17)(cid:3)(cid:55)(cid:75)(cid:76)(cid:86)(cid:3)(cid:71)(cid:72)(cid:70)(cid:85)(cid:72)(cid:68)(cid:86)(cid:72)(cid:3)(cid:85)(cid:72)(cid:404)(cid:72)(cid:70)(cid:87)(cid:86)(cid:3)(cid:87)(cid:75)(cid:72)(cid:3)(cid:81)(cid:82)(cid:81)(cid:70)(cid:68)(cid:86)(cid:75)(cid:15)
after-tax $142 million impairment of Gill Ranch, partially offset by a noncash 
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Excluding these items on a non-GAAP basis, we delivered strong earnings
and performed very well. Adjusted net income was $2.24 per share for 2017,1
up 5 cents compared to $2.19 per share for 2016.2

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ship team and employees to position us for growth and sustainable success.

4

 CORPORATE

   PROFILE

NW NNATURAL (NYSE: NWN)
is a 159-year-old natural 
gas distribution company
headqquartered in 
Portlaand, Oregon.

NW NNATURAL serves nearly 
740,0000 utility customers 
in Oreegon and Southwest 
Washington and provides 
natural gas storage to customers 
on thee West Coast. In keeping
with iits steady growth strategy,
the coompany has increased 
divideends paid to shareholders
for 622 consecutive years.

DAVID ANDERSON at Portland’s Columbia Boulevard Wastewater 
Treatment Plant. In 2017 the city announced it will build a renewable 
natural gas (RNG) processing facility and vehicle fueling station at 
the site in partnership with NW Natural.

2017 HIGHLIGHTS

• Added over 12,700 new customers for an annual growth rate of 1.8 

• Completed major components of the North Mist gas storage

percent, bringing our customer base to nearly 740,000—and marking
2017 as the highest growth rate in a decade.

expansion—a multiyear $132 million project—one of the largest 
projects in NW Natural history.

• Reduced residential customer rates for the third year in a row. Oregon 
customers received a cumulative rate decrease of 15 percent over the 
past three years on top of annual bill credits, and Washington customer
rates dropped a total of 18 percent. 

(cid:274)(cid:3) (cid:40)(cid:68)(cid:85)(cid:81)(cid:72)(cid:71) (cid:87)(cid:75)(cid:72) (cid:75)(cid:76)(cid:74)(cid:75)(cid:72)(cid:86)(cid:87) (cid:70)(cid:88)(cid:86)(cid:87)(cid:82)(cid:80)(cid:72)(cid:85) (cid:86)(cid:68)(cid:87)(cid:76)(cid:86)(cid:73)(cid:68)(cid:70)(cid:87)(cid:76)(cid:82)(cid:81) (cid:86)(cid:70)(cid:82)(cid:85)(cid:72) (cid:73)(cid:82)(cid:85) (cid:87)(cid:75)(cid:72) (cid:403)(cid:73)(cid:87)(cid:75) (cid:92)(cid:72)(cid:68)(cid:85) (cid:76)(cid:81) (cid:68) (cid:85)(cid:82)(cid:90)
among large utilities in the West in the J.D. Power Gas Utility Residential
Customer Satisfaction Study. This is the 10th time in 11 years NW Natural 
has scored second or higher in the nation. We also earned the highest 
customer satisfaction score among utilities in the West in the J.D. Power 
Gas Utility Business Customer Satisfaction Study.

• Invested $214 million of capital expenditures for utility customer growth, 

system reliability and improvements.

• Announced our expansion into the regulated water utility sector with 
planned acquisitions in Oregon and Idaho, which will add about 6,500 
water customers. While these transactions are not material to our 
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(cid:274)(cid:3) (cid:41)(cid:76)(cid:79)(cid:72)(cid:71) (cid:87)(cid:75)(cid:72) (cid:403)(cid:85)(cid:86)(cid:87) (cid:50)(cid:85)(cid:72)(cid:74)(cid:82)(cid:81) (cid:74)(cid:72)(cid:81)(cid:72)(cid:85)(cid:68)(cid:79) (cid:85)(cid:68)(cid:87)(cid:72) (cid:70)(cid:68)(cid:86)(cid:72) (cid:76)(cid:81) (cid:86)(cid:76)(cid:91) (cid:92)(cid:72)(cid:68)(cid:85)(cid:86)(cid:17)

• Increased dividends paid for the 62nd consecutive year, one of the 
longest dividend increase records of any company on the NYSE. 

1(cid:3)(cid:36)(cid:71)(cid:77)(cid:88)(cid:86)(cid:87)(cid:72)(cid:71) (cid:80)(cid:72)(cid:68)(cid:86)(cid:88)(cid:85)(cid:72)(cid:86) (cid:73)(cid:82)(cid:85) (cid:21)(cid:19)(cid:20)(cid:26) (cid:68)(cid:85)(cid:72) (cid:81)(cid:82)(cid:81)(cid:16)(cid:42)(cid:36)(cid:36)(cid:51) (cid:68)(cid:81)(cid:71) (cid:72)(cid:91)(cid:70)(cid:79)(cid:88)(cid:71)(cid:72) (cid:87)(cid:75)(cid:72) (cid:81)(cid:82)(cid:81)(cid:70)(cid:68)(cid:86)(cid:75) (cid:72)(cid:73)(cid:73)(cid:72)(cid:70)(cid:87)(cid:86) (cid:82)(cid:73) (cid:87)(cid:75)(cid:72) (cid:42)(cid:76)(cid:79)(cid:79) (cid:53)(cid:68)(cid:81)(cid:70)(cid:75) (cid:76)(cid:80)(cid:83)(cid:68)(cid:76)(cid:85)(cid:80)(cid:72)(cid:81)(cid:87) (cid:68)(cid:81)(cid:71) (cid:87)(cid:75)(cid:72) (cid:81)(cid:82)(cid:81)(cid:70)(cid:68)(cid:86)(cid:75) (cid:69)(cid:72)(cid:81)(cid:72)(cid:403)(cid:87) (cid:73)(cid:85)(cid:82)(cid:80) (cid:87)(cid:68)(cid:91) (cid:85)(cid:72)(cid:73)(cid:82)(cid:85)(cid:80)

recognized in 2017. See Financial Overview on page 8 for reconciliation.

2(cid:3)(cid:36)(cid:71)(cid:77)(cid:88)(cid:86)(cid:87)(cid:72)(cid:71) (cid:80)(cid:72)(cid:68)(cid:86)(cid:88)(cid:85)(cid:72)(cid:86) (cid:73)(cid:82)(cid:85) (cid:21)(cid:19)(cid:20)(cid:25) (cid:68)(cid:85)(cid:72) (cid:81)(cid:82)(cid:81)(cid:16)(cid:42)(cid:36)(cid:36)(cid:51) (cid:68)(cid:81)(cid:71) (cid:72)(cid:91)(cid:70)(cid:79)(cid:88)(cid:71)(cid:72) (cid:87)(cid:75)(cid:72) (cid:81)(cid:82)(cid:81)(cid:70)(cid:68)(cid:86)(cid:75) (cid:72)(cid:73)(cid:73)(cid:72)(cid:70)(cid:87)(cid:86) (cid:82)(cid:73) (cid:68) (cid:85)(cid:72)(cid:74)(cid:88)(cid:79)(cid:68)(cid:87)(cid:82)(cid:85)(cid:92) (cid:72)(cid:81)(cid:89)(cid:76)(cid:85)(cid:82)(cid:81)(cid:80)(cid:72)(cid:81)(cid:87)(cid:68)(cid:79) (cid:71)(cid:76)(cid:86)(cid:68)(cid:79)(cid:79)(cid:82)(cid:90)(cid:68)(cid:81)(cid:70)(cid:72) (cid:85)(cid:72)(cid:70)(cid:82)(cid:74)(cid:81)(cid:76)(cid:93)(cid:72)(cid:71) (cid:76)(cid:81) (cid:87)(cid:75)(cid:72) (cid:403)(cid:85)(cid:86)(cid:87) (cid:84)(cid:88)(cid:68)(cid:85)(cid:87)(cid:72)(cid:85)

of 2016. See Financial Overview on page 8 for reconciliation.

3

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hood offers hands-on, scenario-based training and replicates
real-world conditions. 

We upgraded facilities across our service 
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centers so crews are positioned to respond
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customer base effectively. 

We also continued our focus on cybersecurity
to ensure NW Natural’s online systems are 
protected with the technology we need to 
safeguard our infrastructure. In 2017, we 
advanced our cybersecurity efforts by imple-
menting additional data encryption, investing in 
industrial control systems infrastructure, and 
increasing employee awareness and training. 

Customer Satisfaction  
LEADS TO GROWTH

Every day, our employees work diligently to
deliver safe, reliable energy and best-in-class
service. It’s why we’ve earned the trust of 
customers and the communities we serve. 

Once again, we’re proud that NW Natural
earned the highest customer satisfaction 
score among large utilities in the West in 
the 2017 J.D. Power Gas Utility Residential
Customer Satisfaction Study. This marks 
the 10th time in 11 years that NW Natural 
has posted among the top two scores for 
residential customer satisfaction in the nation.   

(cid:49)(cid:58) (cid:49)(cid:68)(cid:87)(cid:88)(cid:85)(cid:68)(cid:79) (cid:68)(cid:79)(cid:86)(cid:82) (cid:85)(cid:68)(cid:81)(cid:78)(cid:72)(cid:71) (cid:403)(cid:85)(cid:86)(cid:87) (cid:76)(cid:81) (cid:87)(cid:75)(cid:72) (cid:58)(cid:72)(cid:86)(cid:87)
in the 2017 J.D. Power Gas Utility Business 
Customer Satisfaction Study.

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(cid:75)(cid:82)(cid:90) (cid:86)(cid:68)(cid:87)(cid:76)(cid:86)(cid:403)(cid:72)(cid:71) (cid:82)(cid:88)(cid:85) (cid:70)(cid:88)(cid:86)(cid:87)(cid:82)(cid:80)(cid:72)(cid:85)(cid:86) (cid:73)(cid:72)(cid:72)(cid:79)(cid:17) (cid:55)(cid:75)(cid:72) (cid:70)(cid:82)(cid:86)(cid:87)
of natural gas continued to drop nationally,
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row, we reduced the rates our customers pay.
This winter, Oregon residential customers saw
their bills drop by 6.4 percent, and Washington 
residential customers enjoyed savings of 
3.1 percent. In fact, our customers are paying
20 percent less for natural gas today than
they did 15 years ago.

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competitive position. For the typical home we
serve, heating with a natural gas furnace
provides up to a 70 percent price advantage
over heating with an electric or oil furnace.

SAFETY IN ALL THINGS
System Safety, Employee Training & Preparedness

NW Natural is focused on operating a safe, reliable system and 
delivering outstanding service for our customers and communities.

In 2017, we worked on upgrades to boost our distribution system 
reliability and support our fastest-growing community in Clark 
County, Washington. This project, estimated at $25 million, is 
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(cid:58)(cid:72) (cid:68)(cid:79)(cid:86)(cid:82) (cid:403)(cid:81)(cid:76)(cid:86)(cid:75)(cid:72)(cid:71) (cid:85)(cid:72)(cid:73)(cid:88)(cid:85)(cid:69)(cid:76)(cid:86)(cid:75)(cid:76)(cid:81)(cid:74) (cid:87)(cid:90)(cid:82) (cid:79)(cid:76)(cid:84)(cid:88)(cid:72)(cid:403)(cid:72)(cid:71) (cid:81)(cid:68)(cid:87)(cid:88)(cid:85)(cid:68)(cid:79) (cid:74)(cid:68)(cid:86) (cid:11)(cid:47)(cid:49)(cid:42)(cid:12)
storage facilities, which are critical for delivering natural gas on the
coldest winter days. In 2017, we completed a multiyear $25 million
(cid:88)(cid:83)(cid:74)(cid:85)(cid:68)(cid:71)(cid:72) (cid:68)(cid:87) (cid:82)(cid:88)(cid:85) (cid:49)(cid:72)(cid:90)(cid:83)(cid:82)(cid:85)(cid:87) (cid:47)(cid:49)(cid:42) (cid:73)(cid:68)(cid:70)(cid:76)(cid:79)(cid:76)(cid:87)(cid:92)(cid:15) (cid:82)(cid:85)(cid:76)(cid:74)(cid:76)(cid:81)(cid:68)(cid:79)(cid:79)(cid:92) (cid:69)(cid:88)(cid:76)(cid:79)(cid:87) (cid:76)(cid:81) (cid:20)(cid:28)(cid:26)(cid:26)(cid:17) (cid:36)(cid:87) (cid:82)(cid:88)(cid:85)
(cid:51)(cid:82)(cid:85)(cid:87)(cid:79)(cid:68)(cid:81)(cid:71) (cid:47)(cid:49)(cid:42) (cid:73)(cid:68)(cid:70)(cid:76)(cid:79)(cid:76)(cid:87)(cid:92)(cid:15) (cid:69)(cid:88)(cid:76)(cid:79)(cid:87) (cid:76)(cid:81) (cid:20)(cid:28)(cid:25)(cid:28)(cid:15) (cid:90)(cid:72) (cid:70)(cid:82)(cid:80)(cid:83)(cid:79)(cid:72)(cid:87)(cid:72)(cid:71) (cid:76)(cid:80)(cid:83)(cid:85)(cid:82)(cid:89)(cid:72)(cid:80)(cid:72)(cid:81)(cid:87)(cid:86)
totaling just under $10 million. 

(cid:40)(cid:84)(cid:88)(cid:76)(cid:83)(cid:83)(cid:76)(cid:81)(cid:74) (cid:82)(cid:88)(cid:85) (cid:72)(cid:80)(cid:83)(cid:79)(cid:82)(cid:92)(cid:72)(cid:72)(cid:86) (cid:87)(cid:82) (cid:85)(cid:72)(cid:86)(cid:83)(cid:82)(cid:81)(cid:71) (cid:87)(cid:82) (cid:72)(cid:80)(cid:72)(cid:85)(cid:74)(cid:72)(cid:81)(cid:70)(cid:76)(cid:72)(cid:86) (cid:74)(cid:82)(cid:72)(cid:86) (cid:75)(cid:68)(cid:81)(cid:71) (cid:76)(cid:81)
(cid:75)(cid:68)(cid:81)(cid:71) (cid:90)(cid:76)(cid:87)(cid:75) (cid:78)(cid:72)(cid:72)(cid:83)(cid:76)(cid:81)(cid:74) (cid:82)(cid:88)(cid:85) (cid:86)(cid:92)(cid:86)(cid:87)(cid:72)(cid:80) (cid:86)(cid:68)(cid:73)(cid:72)(cid:17) (cid:49)(cid:58) (cid:49)(cid:68)(cid:87)(cid:88)(cid:85)(cid:68)(cid:79) (cid:403)(cid:72)(cid:79)(cid:71) (cid:72)(cid:80)(cid:83)(cid:79)(cid:82)(cid:92)(cid:72)(cid:72)(cid:86)
regularly participate in extensive training at our state-of-the-art 
training center in Sherwood, Oregon.  

(cid:58)(cid:72) (cid:82)(cid:73)(cid:73)(cid:72)(cid:85) (cid:75)(cid:68)(cid:81)(cid:71)(cid:86)(cid:16)(cid:82)(cid:81)(cid:15) (cid:86)(cid:70)(cid:72)(cid:81)(cid:68)(cid:85)(cid:76)(cid:82)(cid:16)(cid:69)(cid:68)(cid:86)(cid:72)(cid:71) (cid:87)(cid:85)(cid:68)(cid:76)(cid:81)(cid:76)(cid:81)(cid:74) (cid:83)(cid:85)(cid:82)(cid:74)(cid:85)(cid:68)(cid:80)(cid:86) (cid:87)(cid:82) (cid:403)(cid:85)(cid:86)(cid:87)
responders—teaching them about natural gas safety and how 
to work together effectively during a gas emergency. In 2017,
(cid:90)(cid:72) (cid:75)(cid:82)(cid:86)(cid:87)(cid:72)(cid:71) (cid:82)(cid:89)(cid:72)(cid:85) (cid:27)(cid:19) (cid:87)(cid:85)(cid:68)(cid:76)(cid:81)(cid:76)(cid:81)(cid:74)(cid:86) (cid:73)(cid:82)(cid:85) (cid:80)(cid:82)(cid:85)(cid:72) (cid:87)(cid:75)(cid:68)(cid:81) (cid:20)(cid:15)(cid:21)(cid:19)(cid:19) (cid:79)(cid:82)(cid:70)(cid:68)(cid:79) (cid:403)(cid:85)(cid:72)(cid:403)(cid:74)(cid:75)(cid:87)(cid:72)(cid:85)(cid:86)(cid:15)
and we plan to increase that number in 2018.

The cost of natural gas is about 20% lower than it was 15 years ago.

+102%

+41%

+27%

+16%

-20%

Source: Bureau of Labor Statistics

4

ENGAGING CONSTRUCTIVELY  
with Regulators

(cid:15)
(cid:44)(cid:81) (cid:39)(cid:72)(cid:70)(cid:72)(cid:80)(cid:69)(cid:72)(cid:85)
(cid:50)(cid:85)(cid:72)(cid:74)(cid:82)(cid:81) (cid:73)(cid:82)(cid:85) (cid:87)(cid:75)(cid:72) (cid:403)(cid:85)(cid:86)(cid:87) (cid:87)(cid:76)(cid:80)(cid:72) (cid:76)(cid:81) (cid:86)(cid:76)(cid:91) (cid:92)(cid:72)(cid:68)(cid:85)(cid:86)(cid:17)

(cid:21)(cid:19)(cid:20)(cid:26)(cid:15) (cid:68)(cid:73)(cid:87)(cid:72)(cid:85) (cid:70)(cid:68)(cid:85)(cid:72)(cid:73)(cid:88)(cid:79)

(cid:70)(cid:82)(cid:81)(cid:86)(cid:76)(cid:71)(cid:72)(cid:85)(cid:68)(cid:87)(cid:76)(cid:82)(cid:81)(cid:15) (cid:90)(cid:72) (cid:403)(cid:79)(cid:72)(cid:71) (cid:68) (cid:85)(cid:68)(cid:87)(cid:72) (cid:70)(cid:68)(cid:86)(cid:72) (cid:76)(cid:81)

(cid:15)

NW Natural’s Customer Contact Center receives 
approximately one million calls each year.

These advantages—coupled with the strong 
(cid:51)(cid:68)(cid:70)(cid:76)(cid:403)(cid:70) (cid:49)(cid:82)(cid:85)(cid:87)(cid:75)(cid:90)(cid:72)(cid:86)(cid:87) (cid:72)(cid:70)(cid:82)(cid:81)(cid:82)(cid:80)(cid:92)(cid:265)(cid:75)(cid:68)(cid:89)(cid:72) (cid:75)(cid:72)(cid:79)(cid:83)(cid:72)(cid:71) (cid:88)(cid:86)
convert and attract new customers to natural 
gas. At year-end, we reported more than 12,700 
(cid:81)(cid:72)(cid:90) (cid:70)(cid:88)(cid:86)(cid:87)(cid:82)(cid:80)(cid:72)(cid:85)(cid:86)(cid:15) (cid:72)(cid:84)(cid:88)(cid:68)(cid:87)(cid:76)(cid:81)(cid:74) (cid:87)(cid:82) (cid:68) (cid:20)(cid:17)(cid:27) (cid:83)(cid:72)(cid:85)(cid:70)(cid:72)(cid:81)(cid:87) (cid:68)(cid:81)(cid:81)(cid:88)(cid:68)(cid:79)
growth rate—our best performance in a decade.

We also made inroads into the multifamily
sector—which has been historically underserved 
by natural gas — through a comprehensive 
effort to make it easier for developers to build
(cid:90)(cid:76)(cid:87)(cid:75) (cid:81)(cid:68)(cid:87)(cid:88)(cid:85)(cid:68)(cid:79) (cid:74)(cid:68)(cid:86) (cid:90)(cid:76)(cid:87)(cid:75) (cid:72)(cid:84)(cid:88)(cid:76)(cid:83)(cid:80)(cid:72)(cid:81)(cid:87) (cid:76)(cid:81)(cid:70)(cid:72)(cid:81)(cid:87)(cid:76)(cid:89)(cid:72)(cid:86)(cid:15)
streamlined gas infrastructure designs and
promotional support.

In July 2017, the Public Utility Commission of 
(cid:50)(cid:85)(cid:72)(cid:74)(cid:82)(cid:81) (cid:11)(cid:50)(cid:51)(cid:56)(cid:38)(cid:12) (cid:68)(cid:83)(cid:83)(cid:85)(cid:82)(cid:89)(cid:72)(cid:71) (cid:68) (cid:81)(cid:72)(cid:90) (cid:80)(cid:88)(cid:79)(cid:87)(cid:76)(cid:73)(cid:68)(cid:80)(cid:76)(cid:79)(cid:92)
(cid:87)(cid:68)(cid:85)(cid:76)(cid:73)(cid:73) (cid:86)(cid:83)(cid:72)(cid:70)(cid:76)(cid:403)(cid:70)(cid:68)(cid:79)(cid:79)(cid:92) (cid:71)(cid:72)(cid:86)(cid:76)(cid:74)(cid:81)(cid:72)(cid:71) (cid:73)(cid:82)(cid:85) (cid:80)(cid:76)(cid:91)(cid:72)(cid:71)(cid:16)(cid:88)(cid:86)(cid:72)
developments—buildings with commercial
and residential customers —to install natural
gas more easily. 

We will continue to pursue growth in all 
sectors in 2018.

UTILITY CUSTOMERS AT YEAR-END

740,000

720,000

700,000

680,000

660,000

640,000

620,000

600,000

580,000

2013

2014

2015

2016

2017

RESIDENTIAL

COMMERCIAL

INDUSTRIAL

We added 12,728 new customers in 2017, and now serve
nearly 740,000 customers.

(cid:58)(cid:72) (cid:75)(cid:68)(cid:89)(cid:72) (cid:85)(cid:72)(cid:84)(cid:88)(cid:72)(cid:86)(cid:87)(cid:72)(cid:71) (cid:68) (cid:23) (cid:83)(cid:72)(cid:85)(cid:70)(cid:72)(cid:81)(cid:87) (cid:76)(cid:81)(cid:70)(cid:85)(cid:72)(cid:68)(cid:86)(cid:72) (cid:87)(cid:82) (cid:70)(cid:82)(cid:80)(cid:83)(cid:68)(cid:81)(cid:92) (cid:85)(cid:72)(cid:89)(cid:72)(cid:81)(cid:88)(cid:72)(cid:86)(cid:15)
after an adjustment for the conservation tariff deferral, to cover our 
costs to operate and maintain the natural gas distribution system
and continue to provide customers with safe, reliable service.

(cid:55)(cid:75)(cid:72) (cid:50)(cid:51)(cid:56)(cid:38) (cid:68)(cid:81)(cid:71) (cid:82)(cid:87)(cid:75)(cid:72)(cid:85) (cid:86)(cid:87)(cid:68)(cid:78)(cid:72)(cid:75)(cid:82)(cid:79)(cid:71)(cid:72)(cid:85)(cid:86) (cid:90)(cid:76)(cid:79)(cid:79) (cid:85)(cid:72)(cid:89)(cid:76)(cid:72)(cid:90) (cid:82)(cid:88)(cid:85) (cid:403)(cid:79)(cid:76)(cid:81)(cid:74) (cid:87)(cid:75)(cid:85)(cid:82)(cid:88)(cid:74)(cid:75)
a process that could take up to 10 months, with new rates likely 
effective Nov. 1, 2018.

Companies across the country adopted the Federal Tax Cuts and 
Jobs Act at the end of December 2017. For NW Natural, this meant
an earnings increase of $21 million related to nonregulated 
(cid:68)(cid:70)(cid:87)(cid:76)(cid:89)(cid:76)(cid:87)(cid:76)(cid:72)(cid:86)(cid:17) (cid:58)(cid:72) (cid:75)(cid:68)(cid:89)(cid:72) (cid:68) (cid:85)(cid:72)(cid:84)(cid:88)(cid:72)(cid:86)(cid:87) (cid:87)(cid:82) (cid:58)(cid:68)(cid:86)(cid:75)(cid:76)(cid:81)(cid:74)(cid:87)(cid:82)(cid:81) (cid:68)(cid:81)(cid:71) (cid:50)(cid:85)(cid:72)(cid:74)(cid:82)(cid:81) (cid:70)(cid:82)(cid:80)(cid:80)(cid:76)(cid:86)-
(cid:86)(cid:76)(cid:82)(cid:81)(cid:86) (cid:87)(cid:82) (cid:68)(cid:79)(cid:79)(cid:82)(cid:90) (cid:88)(cid:86) (cid:87)(cid:82) (cid:85)(cid:72)(cid:87)(cid:88)(cid:85)(cid:81) (cid:87)(cid:75)(cid:72) (cid:85)(cid:72)(cid:74)(cid:88)(cid:79)(cid:68)(cid:87)(cid:72)(cid:71) (cid:88)(cid:87)(cid:76)(cid:79)(cid:76)(cid:87)(cid:92)(cid:267)(cid:86) (cid:82)(cid:89)(cid:72)(cid:85)(cid:68)(cid:79)(cid:79) (cid:81)(cid:72)(cid:87) (cid:69)(cid:72)(cid:81)(cid:72)(cid:403)(cid:87)(cid:86)
from tax reform to customers. We amended our Oregon rate case 
to address the impact of the lower tax rate and will work closely
with the regulators in the coming months to determine the best
path forward. 

Construction of the 16-inch  portion of the pipeline for the North Mist Expansion 
project is complete.

BUILDING THE FUTURE

Abundant and clean-burning natural gas is a critical resource that
is facilitating a smooth transition to a low-carbon energy future
across the country.

An exciting example is a project to expand our natural gas 
storage infrastructure in Mist, Oregon, which has been integral to 
our ability to support reliable energy service in our region since 
(cid:87)(cid:75)(cid:72) (cid:20)(cid:28)(cid:27)(cid:19)(cid:86)(cid:17) (cid:55)(cid:75)(cid:76)(cid:86) (cid:85)(cid:72)(cid:74)(cid:88)(cid:79)(cid:68)(cid:87)(cid:72)(cid:71) (cid:74)(cid:68)(cid:86) (cid:86)(cid:87)(cid:82)(cid:85)(cid:68)(cid:74)(cid:72) (cid:73)(cid:68)(cid:70)(cid:76)(cid:79)(cid:76)(cid:87)(cid:92) (cid:76)(cid:86) (cid:88)(cid:81)(cid:76)(cid:84)(cid:88)(cid:72)(cid:79)(cid:92) (cid:86)(cid:76)(cid:87)(cid:88)(cid:68)(cid:87)(cid:72)(cid:71)
with limited competition from other facilities and is highly valued 
due to its premium Northwest location. The Mist facility is once
(cid:68)(cid:74)(cid:68)(cid:76)(cid:81) (cid:83)(cid:85)(cid:82)(cid:89)(cid:76)(cid:81)(cid:74) (cid:76)(cid:87)(cid:86) (cid:89)(cid:68)(cid:79)(cid:88)(cid:72) (cid:90)(cid:76)(cid:87)(cid:75) (cid:82)(cid:88)(cid:85) (cid:72)(cid:91)(cid:83)(cid:68)(cid:81)(cid:86)(cid:76)(cid:82)(cid:81) (cid:87)(cid:82) (cid:86)(cid:88)(cid:83)(cid:83)(cid:79)(cid:92) (cid:88)(cid:81)(cid:76)(cid:84)(cid:88)(cid:72)(cid:15)
(cid:81)(cid:82)(cid:16)(cid:81)(cid:82)(cid:87)(cid:76)(cid:70)(cid:72) (cid:86)(cid:72)(cid:85)(cid:89)(cid:76)(cid:70)(cid:72) (cid:87)(cid:75)(cid:68)(cid:87) (cid:51)(cid:82)(cid:85)(cid:87)(cid:79)(cid:68)(cid:81)(cid:71) (cid:42)(cid:72)(cid:81)(cid:72)(cid:85)(cid:68)(cid:79) (cid:40)(cid:79)(cid:72)(cid:70)(cid:87)(cid:85)(cid:76)(cid:70) (cid:11)(cid:51)(cid:42)(cid:40)(cid:12) (cid:70)(cid:68)(cid:81) (cid:71)(cid:85)(cid:68)(cid:90)
on rapidly to integrate more wind power into the grid, ensuring
reliable natural gas backup response.

5

NW Natural Environmental Managgement and Sustainabilityy 
Director Bill Edmonds with President and CEO David Anderson.

)
(in millions)
illi
(i

$300

$250

$200

$150

$100

$50

$0

2013

2014

2015

2016

2017

CUSTOMER
GROWTH

SAFETY AND
RELIABILITY

OTHER

NORTH
MIST

Total investment in capital expenditures during 2017 was 
more than $250 million on an accrual basis.

There are three major components to this 
$132 million project: a new underground
reservoir providing up to 2.5 billion cubic feet
of available storage, an additional compressor 
station, and a new dedicated 13-mile pipeline 
to connect NW Natural’s facility to PGE’s 
Port Westward industrial park. 

The investment will be included in rates under
an established tariff when it is placed into 
service with an initial 30-year contract with 
options to extend totaling up to an additional
50 years upon mutual agreement.

LOW CARBON PATHWAY

Just as we’re able to support renewable energy with the North
Mist project, we know there are other ways NW Natural can help
the region move to a low-carbon future. 

Today, natural gas is the cleanest option to reliably meet our 
region’s biggest energy needs. In Oregon, NW Natural delivers
more energy over a year than any other utility, yet the use of 
natural gas—in our customers’ homes, businesses and industry 
—accounts for about 8 percent of Oregon’s total greenhouse
gas emissions.

OREGON GREENHOUSE GAS EMISSIONS

Source: Oregon DEQ
In-Boundary GHG 
Inventory 2015 data. 

6

(cid:58)(cid:75)(cid:76)(cid:79)(cid:72) (cid:90)(cid:72) (cid:87)(cid:75)(cid:76)(cid:81)(cid:78) (cid:87)(cid:75)(cid:68)(cid:87)(cid:267)(cid:86) (cid:68) (cid:83)(cid:85)(cid:72)(cid:87)(cid:87)(cid:92) (cid:72)(cid:73)(cid:403)(cid:70)(cid:76)(cid:72)(cid:81)(cid:87) (cid:86)(cid:87)(cid:68)(cid:85)(cid:87)(cid:76)(cid:81)(cid:74) (cid:83)(cid:82)(cid:76)(cid:81)(cid:87)(cid:15) (cid:90)(cid:72) (cid:69)(cid:72)(cid:79)(cid:76)(cid:72)(cid:89)(cid:72)
we can do even better. It’s why we set a voluntary goal of 30 percent 
carbon emissions savings by 2035, with a starting point of 2015
emission levels. 

(cid:44)(cid:81) (cid:21)(cid:19)(cid:20)(cid:26)(cid:15) (cid:90)(cid:72) (cid:76)(cid:71)(cid:72)(cid:81)(cid:87)(cid:76)(cid:403)(cid:72)(cid:71) (cid:81)(cid:72)(cid:90) (cid:82)(cid:83)(cid:83)(cid:82)(cid:85)(cid:87)(cid:88)(cid:81)(cid:76)(cid:87)(cid:76)(cid:72)(cid:86) (cid:87)(cid:82) (cid:83)(cid:85)(cid:82)(cid:68)(cid:70)(cid:87)(cid:76)(cid:89)(cid:72)(cid:79)(cid:92) (cid:85)(cid:72)(cid:71)(cid:88)(cid:70)(cid:72)
emissions using our existing infrastructure — one of the most
modern, tightest pipeline systems in the nation. 

(cid:58)(cid:72) (cid:68)(cid:85)(cid:72) (cid:72)(cid:86)(cid:83)(cid:72)(cid:70)(cid:76)(cid:68)(cid:79)(cid:79)(cid:92) (cid:72)(cid:91)(cid:70)(cid:76)(cid:87)(cid:72)(cid:71) (cid:68)(cid:69)(cid:82)(cid:88)(cid:87) (cid:68) (cid:85)(cid:72)(cid:81)(cid:72)(cid:90)(cid:68)(cid:69)(cid:79)(cid:72) (cid:81)(cid:68)(cid:87)(cid:88)(cid:85)(cid:68)(cid:79) (cid:74)(cid:68)(cid:86) (cid:11)(cid:53)(cid:49)(cid:42)(cid:12)
project with the City of Portland. Announced in April 2017, the city
is building an RNG production facility at its largest wastewater
treatment plant to recover and clean biogas to meet our pipeline 
(cid:84)(cid:88)(cid:68)(cid:79)(cid:76)(cid:87)(cid:92) (cid:86)(cid:87)(cid:68)(cid:81)(cid:71)(cid:68)(cid:85)(cid:71)(cid:86)(cid:17) (cid:36) (cid:83)(cid:82)(cid:85)(cid:87)(cid:76)(cid:82)(cid:81) (cid:82)(cid:73) (cid:87)(cid:75)(cid:72) (cid:85)(cid:72)(cid:86)(cid:88)(cid:79)(cid:87)(cid:76)(cid:81)(cid:74) (cid:53)(cid:49)(cid:42) (cid:90)(cid:76)(cid:79)(cid:79) (cid:69)(cid:72) (cid:88)(cid:86)(cid:72)(cid:71) (cid:87)(cid:82)
fuel heavy-duty vehicles locally, and the rest will be injected into
NW Natural’s existing pipeline system.

NW Natural built and installed the vehicle fueling station in 2017 
and will maintain it for the city. We expect the entire project to be 
(cid:82)(cid:83)(cid:72)(cid:85)(cid:68)(cid:87)(cid:76)(cid:82)(cid:81)(cid:68)(cid:79) (cid:69)(cid:92) (cid:72)(cid:68)(cid:85)(cid:79)(cid:92) (cid:21)(cid:19)(cid:20)(cid:28)(cid:17) (cid:58)(cid:72)(cid:267)(cid:85)(cid:72) (cid:83)(cid:85)(cid:82)(cid:88)(cid:71) (cid:87)(cid:82) (cid:83)(cid:68)(cid:85)(cid:87)(cid:81)(cid:72)(cid:85) (cid:90)(cid:76)(cid:87)(cid:75) (cid:87)(cid:75)(cid:72) (cid:38)(cid:76)(cid:87)(cid:92) (cid:82)(cid:73)
Portland on its single largest climate action effort to date.

Collaboration is a pivotal part of reaching our carbon savings goal
—and we’re working on many fronts up and down the natural gas

value chain. Because our customers are
key partners, we launched a multiyear 
(cid:82)(cid:88)(cid:87)(cid:85)(cid:72)(cid:68)(cid:70)(cid:75) (cid:70)(cid:68)(cid:80)(cid:83)(cid:68)(cid:76)(cid:74)(cid:81)(cid:265) (cid:47)(cid:72)(cid:86)(cid:86) (cid:58)(cid:72) (cid:38)(cid:68)(cid:81) (cid:265)
inviting them to join us in working toward 
a low-carbon future. We are working in 
g
the communities we serve and have 
shared the company’s low-carbon vision
with more than 100 policymakers and
stakeholders.

In 2017, NW Natural also hosted the
(cid:85)(cid:72)(cid:74)(cid:76)(cid:82)(cid:81)(cid:267)(cid:86) (cid:403)(cid:85)(cid:86)(cid:87) (cid:53)(cid:49)(cid:42) (cid:70)(cid:82)(cid:81)(cid:73)(cid:72)(cid:85)(cid:72)(cid:81)(cid:70)(cid:72)(cid:15) (cid:70)(cid:72)(cid:79)(cid:72)(cid:69)(cid:85)(cid:68)(cid:87)(cid:72)(cid:71)
10 years of our Smart Energy carbon
offset program, and joined the Natural
(cid:42)(cid:68)(cid:86) (cid:54)(cid:88)(cid:83)(cid:83)(cid:79)(cid:92) (cid:70)(cid:82)(cid:79)(cid:79)(cid:68)(cid:69)(cid:82)(cid:85)(cid:68)(cid:87)(cid:76)(cid:89)(cid:72) (cid:87)(cid:82) (cid:76)(cid:81)(cid:404)(cid:88)(cid:72)(cid:81)(cid:70)(cid:72)
upstream production practices. 

But these steps are just part of the story.
We are also focused on new technologies

Idaho Falls is one of two locations where NW Natural plans to acquire 
a water utility.

to reduce our emissions footprint. Power-to-Gas is a cutting-edge 
process that captures surplus wind and solar energy and converts 
it to RNG or hydrogen through electrolysis. This renewable energy 
could be stored and then blended into our pipeline system to one 
day serve homes, businesses and vehicles.

FUTURE OPPORTUNITIES

(cid:47)(cid:82)(cid:82)(cid:78)(cid:76)(cid:81)(cid:74) (cid:87)(cid:82) (cid:87)(cid:75)(cid:72) (cid:73)(cid:88)(cid:87)(cid:88)(cid:85)(cid:72)(cid:15) (cid:90)(cid:72) (cid:85)(cid:72)(cid:80)(cid:68)(cid:76)(cid:81) (cid:73)(cid:82)(cid:70)(cid:88)(cid:86)(cid:72)(cid:71) (cid:82)(cid:81) (cid:74)(cid:85)(cid:82)(cid:90)(cid:76)(cid:81)(cid:74) (cid:82)(cid:88)(cid:85) (cid:81)(cid:68)(cid:87)(cid:88)(cid:85)(cid:68)(cid:79)
gas utility business and examining opportunities that are a good
(cid:403)(cid:87) (cid:73)(cid:82)(cid:85) (cid:82)(cid:88)(cid:85) (cid:72)(cid:91)(cid:83)(cid:72)(cid:85)(cid:87)(cid:76)(cid:86)(cid:72)(cid:15) (cid:70)(cid:85)(cid:72)(cid:68)(cid:87)(cid:72) (cid:89)(cid:68)(cid:79)(cid:88)(cid:72) (cid:68)(cid:81)(cid:71) (cid:83)(cid:85)(cid:82)(cid:89)(cid:76)(cid:71)(cid:72) (cid:68) (cid:86)(cid:76)(cid:80)(cid:76)(cid:79)(cid:68)(cid:85) (cid:85)(cid:76)(cid:86)(cid:78)
(cid:83)(cid:85)(cid:82)(cid:403)(cid:79)(cid:72) (cid:87)(cid:82) (cid:82)(cid:88)(cid:85) (cid:76)(cid:81)(cid:89)(cid:72)(cid:86)(cid:87)(cid:82)(cid:85)(cid:86)(cid:17)

(cid:58)(cid:72) (cid:87)(cid:82)(cid:82)(cid:78) (cid:68)(cid:81) (cid:72)(cid:91)(cid:70)(cid:76)(cid:87)(cid:76)(cid:81)(cid:74) (cid:403)(cid:85)(cid:86)(cid:87) (cid:86)(cid:87)(cid:72)(cid:83) (cid:76)(cid:81) (cid:39)(cid:72)(cid:70)(cid:72)(cid:80)(cid:69)(cid:72)(cid:85) (cid:21)(cid:19)(cid:20)(cid:26) (cid:90)(cid:75)(cid:72)(cid:81) (cid:90)(cid:72)
announced our expansion into the regulated water sector with
(cid:83)(cid:79)(cid:68)(cid:81)(cid:81)(cid:72)(cid:71) (cid:68)(cid:70)(cid:84)(cid:88)(cid:76)(cid:86)(cid:76)(cid:87)(cid:76)(cid:82)(cid:81)(cid:86) (cid:82)(cid:73) (cid:87)(cid:90)(cid:82) (cid:90)(cid:68)(cid:87)(cid:72)(cid:85) (cid:88)(cid:87)(cid:76)(cid:79)(cid:76)(cid:87)(cid:76)(cid:72)(cid:86) (cid:90)(cid:76)(cid:87)(cid:75) (cid:81)(cid:72)(cid:68)(cid:85)(cid:79)(cid:92) (cid:25)(cid:15)(cid:24)(cid:19)(cid:19)
customers in Oregon and Idaho. We view regulated water utility 
(cid:82)(cid:83)(cid:83)(cid:82)(cid:85)(cid:87)(cid:88)(cid:81)(cid:76)(cid:87)(cid:76)(cid:72)(cid:86) (cid:68)(cid:86) (cid:68)(cid:81) (cid:72)(cid:91)(cid:70)(cid:72)(cid:79)(cid:79)(cid:72)(cid:81)(cid:87) (cid:86)(cid:87)(cid:85)(cid:68)(cid:87)(cid:72)(cid:74)(cid:76)(cid:70) (cid:403)(cid:87) (cid:73)(cid:82)(cid:85) (cid:82)(cid:88)(cid:85) (cid:70)(cid:82)(cid:80)(cid:83)(cid:68)(cid:81)(cid:92)(cid:17)
NW Natural’s core competencies — customer service, safety, 
environmental stewardship, reliability and managing critical 
distribution infrastructure—are directly applicable to the water
utility business. 

With substantial investment opportunities in the water sector
over the long term, we will be working to build out this broader
strategy in the coming years.

To better respond to growth opportunities, like our regulated 
water strategy, we are seeking a corporate holding company
structure. This structure is widely used, particularly among
utilities, and would allow us to further serve the best interests
(cid:82)(cid:73) (cid:86)(cid:75)(cid:68)(cid:85)(cid:72)(cid:75)(cid:82)(cid:79)(cid:71)(cid:72)(cid:85)(cid:86) (cid:69)(cid:92) (cid:83)(cid:85)(cid:82)(cid:89)(cid:76)(cid:71)(cid:76)(cid:81)(cid:74) (cid:68) (cid:80)(cid:82)(cid:85)(cid:72) (cid:68)(cid:74)(cid:76)(cid:79)(cid:72) (cid:68)(cid:81)(cid:71) (cid:72)(cid:73)(cid:403)(cid:70)(cid:76)(cid:72)(cid:81)(cid:87) (cid:83)(cid:79)(cid:68)(cid:87)(cid:73)(cid:82)(cid:85)(cid:80)
to pursue new growth opportunities. Our business operations 
and strategy would not change — we remain focused on stable,
utility-type earnings growth for investors and safe, reliable service
for our customers.

GROWTH  
TODAY AND TOMORROW

(cid:47)(cid:72)(cid:68)(cid:71)(cid:76)(cid:81)(cid:74) (cid:68) (cid:70)(cid:82)(cid:80)(cid:83)(cid:68)(cid:81)(cid:92) (cid:82)(cid:73) (cid:81)(cid:72)(cid:68)(cid:85)(cid:79)(cid:92) (cid:20)(cid:15)(cid:21)(cid:19)(cid:19) (cid:72)(cid:80)(cid:83)(cid:79)(cid:82)(cid:92)(cid:72)(cid:72)(cid:86)
who live our core values and share a common
vision for the future inspires me every day.
Their dedication, innovation and energy fuel
our success and keep us nimble.

We made tough decisions and achieved great
things in 2017. I look forward to building on what
we’ve created—a strong foundation positioned 
(cid:73)(cid:82)(cid:85) (cid:86)(cid:88)(cid:86)(cid:87)(cid:68)(cid:76)(cid:81)(cid:68)(cid:69)(cid:79)(cid:72) (cid:74)(cid:85)(cid:82)(cid:90)(cid:87)(cid:75)(cid:17) (cid:44)(cid:267)(cid:80) (cid:70)(cid:82)(cid:81)(cid:403)(cid:71)(cid:72)(cid:81)(cid:87) (cid:90)(cid:72) (cid:90)(cid:76)(cid:79)(cid:79)
make the most of the opportunities ahead.         

NW Natural has consistently led the industry
on many fronts: environmental stewardship, 
(cid:86)(cid:92)(cid:86)(cid:87)(cid:72)(cid:80) (cid:72)(cid:73)(cid:403)(cid:70)(cid:76)(cid:72)(cid:81)(cid:70)(cid:92) (cid:68)(cid:81)(cid:71) (cid:80)(cid:82)(cid:71)(cid:72)(cid:85)(cid:81)(cid:76)(cid:93)(cid:68)(cid:87)(cid:76)(cid:82)(cid:81)(cid:15)
customer service, and commitment to our
communities. We take this legacy seriously 
and will continue to focus on delivering the 
highest level of performance. 

(cid:55)(cid:75)(cid:68)(cid:81)(cid:78) (cid:92)(cid:82)(cid:88) (cid:73)(cid:82)(cid:85) (cid:92)(cid:82)(cid:88)(cid:85) (cid:70)(cid:82)(cid:81)(cid:403)(cid:71)(cid:72)(cid:81)(cid:70)(cid:72) (cid:68)(cid:81)(cid:71) (cid:87)(cid:85)(cid:88)(cid:86)(cid:87) (cid:76)(cid:81)
NW Natural. We look forward to working 
on your behalf in the year ahead.

David H. Anderson
(cid:51)(cid:85)(cid:72)(cid:86)(cid:76)(cid:71)(cid:72)(cid:81)(cid:87) (cid:68)(cid:81)(cid:71) (cid:38)(cid:75)(cid:76)(cid:72)(cid:73) (cid:40)(cid:91)(cid:72)(cid:70)(cid:88)(cid:87)(cid:76)(cid:89)(cid:72) (cid:50)(cid:73)(cid:403)(cid:70)(cid:72)(cid:85)

7

 FINANCIAL OVERVIEW 

2017 

2016

EARNINGS
(cid:41)(cid:76)(cid:81)(cid:68)(cid:81)(cid:70)(cid:76)(cid:68)(cid:79) (cid:73)(cid:68)(cid:70)(cid:87)(cid:86) (cid:11)(cid:7)(cid:19)(cid:19)(cid:19)(cid:12)(cid:29)

(cid:85)(cid:72)(cid:89)(cid:72)(cid:81)(cid:88)(cid:72)(cid:86)
(cid:50)(cid:83)(cid:72)(cid:85)(cid:68)(cid:87)(cid:76)(cid:81)(cid:74) (cid:85)(cid:72)(cid:89)(cid:72)(cid:81)(cid:88)(cid:72)(cid:86)
(cid:50)(cid:83)(cid:72)(cid:85)(cid:68)(cid:87)(cid:76)(cid:81)(cid:74)
Utility margin1
(cid:49)(cid:72)(cid:87) (cid:76)(cid:81)(cid:70)(cid:82)(cid:80)(cid:72) (cid:11)(cid:79)(cid:82)(cid:86)(cid:86)(cid:12)
Adjusted net income

(cid:3)

COMMON STOCK
(cid:54)(cid:75)(cid:68)(cid:85)(cid:72)(cid:75)(cid:82)(cid:79)(cid:71)(cid:72)(cid:85) (cid:71)(cid:68)(cid:87)(cid:68) (cid:11)(cid:19)(cid:19)(cid:19)(cid:12)(cid:29)(cid:3)

(cid:36)(cid:89)(cid:72)(cid:85)(cid:68)(cid:74)(cid:72) (cid:86)(cid:75)(cid:68)(cid:85)(cid:72)(cid:86) (cid:82)(cid:88)(cid:87)(cid:86)(cid:87)(cid:68)(cid:81)(cid:71)(cid:76)(cid:81)(cid:74)(cid:264)(cid:71)(cid:76)(cid:79)(cid:88)(cid:87)(cid:72)(cid:71)(cid:3)
Year-end shares outstanding

(cid:51)(cid:72)(cid:85) (cid:86)(cid:75)(cid:68)(cid:85)(cid:72) (cid:71)(cid:68)(cid:87)(cid:68) (cid:11)(cid:7)(cid:12)(cid:29)(cid:3)

(cid:39)(cid:76)(cid:79)(cid:88)(cid:87)(cid:72)(cid:71) (cid:72)(cid:68)(cid:85)(cid:81)(cid:76)(cid:81)(cid:74)(cid:86) (cid:11)(cid:79)(cid:82)(cid:86)(cid:86)(cid:12)
Adjusted diluted earnings
Dividends paid
Book value at year-end
(cid:48)(cid:68)(cid:85)(cid:78)(cid:72)(cid:87) (cid:89)(cid:68)(cid:79)(cid:88)(cid:72) (cid:68)(cid:87) (cid:92)(cid:72)(cid:68)(cid:85)(cid:16)(cid:72)(cid:81)(cid:71)(cid:3)

UTILITY OPERATING HIGHLIGHTS

(cid:42)(cid:68)(cid:86) (cid:71)(cid:72)(cid:79)(cid:76)(cid:89)(cid:72)(cid:85)(cid:76)(cid:72)(cid:86) (cid:11)(cid:19)(cid:19)(cid:19) (cid:87)(cid:75)(cid:72)(cid:85)(cid:80)(cid:86)(cid:12)
Degree days
Customers at year-end
Employees at year-end

DIVIDENDS PAID ON COMMON STOCK (cid:11)(cid:83)(cid:72)(cid:85) (cid:86)(cid:75)(cid:68)(cid:85)(cid:72)(cid:12)
Payment date
February
May
August
November

Total dividends paid

(cid:26)(cid:25)(cid:21)(cid:15)(cid:20)(cid:26)(cid:22)
(cid:26)(cid:25)(cid:21)(cid:15)(cid:20)(cid:26)(cid:22)(cid:3)
(cid:22)(cid:28)(cid:21)(cid:15)(cid:25)(cid:22)(cid:21)(cid:3)
(cid:11)(cid:24)(cid:24)(cid:15)(cid:25)(cid:21)(cid:22)(cid:12)(cid:3)
 64,4702

(cid:25)(cid:26)(cid:24)(cid:15)(cid:28)(cid:25)(cid:26)
(cid:25)(cid:26)(cid:24)(cid:15)(cid:28)(cid:25)(cid:26)
(cid:22)(cid:26)(cid:25)(cid:15)(cid:24)(cid:28)(cid:20)(cid:3)
(cid:24)(cid:27)(cid:15)(cid:27)(cid:28)(cid:24)
(cid:25)(cid:19)(cid:15)(cid:27)(cid:28)(cid:20)3

(cid:21)(cid:27)(cid:15)(cid:25)(cid:25)(cid:28)(cid:3)
 28,736

(cid:3)

(cid:21)(cid:26)(cid:15)(cid:26)(cid:26)(cid:28)
28,630

(cid:11)(cid:20)(cid:17)(cid:28)(cid:23)(cid:12)
2.242
1.88
(cid:21)(cid:24)(cid:17)(cid:27)(cid:24)(cid:3)
(cid:24)(cid:28)(cid:17)(cid:25)(cid:24)

(cid:21)(cid:17)(cid:20)(cid:21)
(cid:21)(cid:17)(cid:20)(cid:28)3
1.87
(cid:21)(cid:28)(cid:17)(cid:26)(cid:20)
(cid:24)(cid:28)(cid:17)(cid:27)(cid:19)

(cid:20)(cid:15)(cid:21)(cid:23)(cid:19)(cid:15)(cid:21)(cid:28)(cid:22)(cid:3)
4,553
737,874
1,146

(cid:20)(cid:15)(cid:19)(cid:27)(cid:23)(cid:15)(cid:28)(cid:28)(cid:25)
3,551
725,146
1,108

$0.4700 
0.4700 
0.4700 
0.4725
$1.8825

 $0.4675
 0.4675
 0.4675 
0.4700
$1.8725

UTILITY  MARGIN
(in $000)

DIVIDENDS PAID PER SHARE
($)

$400,000

$390,000

$380,000

$370,000

$360,000

$350,000

$340,000

$330,000

2013

2014

2015

2016

2017

Utility margin increased $16.0 million to 
(cid:7)(cid:22)(cid:28)(cid:21)(cid:17)(cid:25) (cid:80)(cid:76)(cid:79)(cid:79)(cid:76)(cid:82)(cid:81) (cid:76)(cid:81) (cid:21)(cid:19)(cid:20)(cid:26)(cid:17)

$1.90

$1.85

$1.80

$1.75

$1.70

$1.65

$1.60

$1.55

2013

2014

2015

2016

2017

Annual dividends paid per share in 2017
increased for the 62nd consecutive year.
The current indicated annual dividend is
(cid:7)(cid:20)(cid:17)(cid:27)(cid:28) (cid:83)(cid:72)(cid:85) (cid:86)(cid:75)(cid:68)(cid:85)(cid:72)(cid:17)

 SERVICE TERRITORY
AND STORAGE FACILITIES

WASHINGTON

AS
SASASTORIA

MIST 
STORAGE

VANCOUVERR
GASCO LNG

PORTLANDD
D

THE DALLES

TRAINING 
CENTER

LINCOLN CITY

NEWPORT LNG

SALEM

ALBANY

EUGENE

OREGON

COOS BAYAY
AYAY

KEY

NW NATURAL SERVICE TERRITORY
TRAINING CENTER
REGIONAL RESOURCE CENTER
LNG PLANT
UNDERGROUND STORAGE
HEADQUARTERS

SASAN FRANCISCO

1 References to the utility margin refer to utility segment.

CALIFORNIA

GILL RANCH
STORAGE

FRESNO

2 (cid:36)(cid:71)(cid:77)(cid:88)(cid:86)(cid:87)(cid:72)(cid:71) (cid:70)(cid:82)(cid:81)(cid:86)(cid:82)(cid:79)(cid:76)(cid:71)(cid:68)(cid:87)(cid:72)(cid:71) (cid:81)(cid:72)(cid:87) (cid:76)(cid:81)(cid:70)(cid:82)(cid:80)(cid:72) (cid:68)(cid:81)(cid:71) (cid:40)(cid:51)(cid:54) (cid:73)(cid:82)(cid:85) (cid:21)(cid:19)(cid:20)(cid:26) (cid:68)(cid:85)(cid:72) (cid:81)(cid:82)(cid:81)(cid:16)(cid:42)(cid:36)(cid:36)(cid:51) (cid:403)(cid:81)(cid:68)(cid:81)(cid:70)(cid:76)(cid:68)(cid:79) (cid:80)(cid:72)(cid:68)(cid:86)(cid:88)(cid:85)(cid:72)(cid:86) (cid:87)(cid:75)(cid:68)(cid:87) (cid:72)(cid:91)(cid:70)(cid:79)(cid:88)(cid:71)(cid:72) (cid:87)(cid:75)(cid:72) (cid:42)(cid:76)(cid:79)(cid:79) (cid:53)(cid:68)(cid:81)(cid:70)(cid:75)
(cid:76)(cid:80)(cid:83)(cid:68)(cid:76)(cid:85)(cid:80)(cid:72)(cid:81)(cid:87) (cid:82)(cid:73) (cid:7)(cid:20)(cid:28)(cid:21)(cid:17)(cid:24) (cid:80)(cid:76)(cid:79)(cid:79)(cid:76)(cid:82)(cid:81) (cid:83)(cid:85)(cid:72)(cid:87)(cid:68)(cid:91) (cid:82)(cid:85) (cid:7)(cid:20)(cid:23)(cid:20)(cid:17)(cid:24) (cid:80)(cid:76)(cid:79)(cid:79)(cid:76)(cid:82)(cid:81) (cid:68)(cid:73)(cid:87)(cid:72)(cid:85)(cid:16)(cid:87)(cid:68)(cid:91) (cid:68)(cid:81)(cid:71) (cid:87)(cid:75)(cid:72) (cid:7)(cid:21)(cid:20)(cid:17)(cid:23) (cid:80)(cid:76)(cid:79)(cid:79)(cid:76)(cid:82)(cid:81) (cid:69)(cid:72)(cid:81)(cid:72)(cid:403)(cid:87) (cid:85)(cid:72)(cid:79)(cid:68)(cid:87)(cid:72)(cid:71) (cid:87)(cid:82) (cid:76)(cid:80)(cid:83)(cid:79)(cid:72)(cid:80)(cid:72)(cid:81)(cid:87)-
ing tax reform. The after-tax impairment is calculated using the combined federal and state statutory tax rate of 
26.5%. EPS is calculated using 28.7 million diluted shares. 

3(cid:3)(cid:36)(cid:71)(cid:77)(cid:88)(cid:86)(cid:87)(cid:72)(cid:71) (cid:70)(cid:82)(cid:81)(cid:86)(cid:82)(cid:79)(cid:76)(cid:71)(cid:68)(cid:87)(cid:72)(cid:71) (cid:81)(cid:72)(cid:87) (cid:76)(cid:81)(cid:70)(cid:82)(cid:80)(cid:72) (cid:68)(cid:81)(cid:71) (cid:40)(cid:51)(cid:54) (cid:73)(cid:82)(cid:85) (cid:21)(cid:19)(cid:20)(cid:25) (cid:68)(cid:85)(cid:72) (cid:81)(cid:82)(cid:81)(cid:16)(cid:42)(cid:36)(cid:36)(cid:51) (cid:403)(cid:81)(cid:68)(cid:81)(cid:70)(cid:76)(cid:68)(cid:79) (cid:80)(cid:72)(cid:68)(cid:86)(cid:88)(cid:85)(cid:72)(cid:86) (cid:87)(cid:75)(cid:68)(cid:87) (cid:72)(cid:91)(cid:70)(cid:79)(cid:88)(cid:71)(cid:72) (cid:87)(cid:75)(cid:72) (cid:85)(cid:72)(cid:74)(cid:88)(cid:79)(cid:68)(cid:87)(cid:82)(cid:85)(cid:92)
environmental disallowance of $3.3 million pretax or $2.0 million after-tax. The after-tax disallowance is calculated 
(cid:88)(cid:86)(cid:76)(cid:81)(cid:74) (cid:87)(cid:75)(cid:72) (cid:70)(cid:82)(cid:80)(cid:69)(cid:76)(cid:81)(cid:72)(cid:71) (cid:73)(cid:72)(cid:71)(cid:72)(cid:85)(cid:68)(cid:79) (cid:68)(cid:81)(cid:71) (cid:86)(cid:87)(cid:68)(cid:87)(cid:72) (cid:86)(cid:87)(cid:68)(cid:87)(cid:88)(cid:87)(cid:82)(cid:85)(cid:92) (cid:87)(cid:68)(cid:91) (cid:85)(cid:68)(cid:87)(cid:72) (cid:82)(cid:73) (cid:22)(cid:28)(cid:17)(cid:24)(cid:8)(cid:17) (cid:40)(cid:51)(cid:54) (cid:76)(cid:86) (cid:70)(cid:68)(cid:79)(cid:70)(cid:88)(cid:79)(cid:68)(cid:87)(cid:72)(cid:71) (cid:88)(cid:86)(cid:76)(cid:81)(cid:74) (cid:21)(cid:26)(cid:17)(cid:27) (cid:80)(cid:76)(cid:79)(cid:79)(cid:76)(cid:82)(cid:81) (cid:71)(cid:76)(cid:79)(cid:88)(cid:87)(cid:72)(cid:71) (cid:86)(cid:75)(cid:68)(cid:85)(cid:72)(cid:86)(cid:17)

8

 
 
 
 
 
 
 
 
 
 
CORPORATE OFFICERS

BOARD OF DIRECTORS

DAVID H. ANDERSON
President and
Chief Executive Officer

FRANK BURKHARTSMEYER
Senior Vice President and
Chief Financial Officer

LEA ANNE DOOLITTLE
Senior Vice President and 
Chief Administrative Officer

DAVID H. ANDERSON
President and Chief Executive
Officer, NW Natural

TIMOTHY P. BOYLE
President and Chief Executive 
Officer, Columbia Sportswear
Company

JAMES DOWNING
Vice President and 
Chief Information Officer

SHAWN M. FILIPPI
Vice President, Chief Compliance
Officer and Corporate Secretary

KIMBERLY HEITING
Senior Vice President
Operations and 
Chief Marketing Officer

MARTHA L. “STORMY”
BYORUM
Chief Executive Officer, 
Cori Investment Advisors, LLC

JOHN D. CARTER
Chairman of the Board,
Schnitzer Steel Industries, Inc.

THOMAS J. IMESON
Vice President Public Affairs

JUSTIN B. PALFREYMAN
Vice President, Strategy and 
Business Development

LORI L. RUSSELL
Vice President Utility Services

MARK S. DODSON
Former Chief Executive 
Officer, NW Natural

C. SCOTT GIBSON
President, Gibson Enterprises

MARDILYN SAATHOFF
Senior Vice President,
Regulation and General Counsel

BRODY J. WILSON
Vice President, 
Chief Accounting Officer, 
Controller and Treasurer

GRANT M. YOSHIHARA
Senior Vice President
Utility Operations

TOD R. HAMACHEK
Chairman of the Board,
NW Natural

JANE L. PEVERETT
Former President and Chief
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Transmission Corporation

OUR MISSION
We provide safe, reliable
and affordable energy 
in an environmentally 
responsible way to better
the lives of the public 
we serve.

OUR CORE VALUES
Integrity
Safety
Service Ethic
Caring
Environmental Stewardship

KENNETH THRASHER
Chairman of the Board,
Compli Corporation

MALIA H. WASSON
Former Executive 
Vice President of Commercial
Banking, U.S. Bank

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CORPORATE INFORMATION

Notice of Annual Meeting

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(cid:28)(cid:26)(cid:21)(cid:19)(cid:28) (cid:36)(cid:36) (cid:80)(cid:72)(cid:72)(cid:87)(cid:76)(cid:81)(cid:74)(cid:76)
(cid:28)(cid:26)(cid:21)(cid:19)(cid:28)(cid:17)

(cid:55)(cid:75)(cid:72) (cid:21)(cid:19)(cid:20)(cid:27) (cid:36)(cid:81)(cid:81)(cid:88)(cid:68)(cid:79) (cid:48)(cid:72)(cid:72)(cid:87)(cid:76)(cid:81)(cid:74) (cid:90)(cid:76)(cid:79)(cid:79) (cid:69)(cid:72) (cid:75)(cid:72)(cid:79)(cid:71) (cid:68)(cid:87) (cid:21) (cid:83)(cid:17)(cid:80)(cid:17)(cid:15) (cid:55)(cid:75)(cid:88)(cid:85)(cid:86)(cid:71)(cid:68)(cid:92)(cid:15) (cid:48)(cid:68)(cid:92) (cid:21)(cid:23)(cid:15) (cid:68)(cid:87) (cid:87)(cid:75)(cid:72) (cid:70)(cid:82)(cid:80)(cid:83)(cid:68)(cid:81)(cid:92)(cid:267)(cid:86) (cid:75)(cid:72)(cid:68)(cid:71)(cid:84)(cid:88)(cid:68)(cid:85)(cid:87)(cid:72)(cid:85)(cid:86)(cid:15) (cid:50)(cid:81)(cid:72) (cid:51)(cid:68)(cid:70)(cid:76)(cid:403)(cid:70) (cid:54)(cid:84)(cid:88)(cid:68)(cid:85)(cid:72)(cid:15) (cid:21)(cid:21)(cid:19) (cid:49)(cid:58) (cid:21)(cid:81)(cid:71) (cid:36)(cid:89)(cid:72)(cid:17)(cid:15)
(cid:87)(cid:82) (cid:68)(cid:87)(cid:87)(cid:72)(cid:81)(cid:71)(cid:71)
(cid:404)
(cid:23)(cid:87)(cid:75)(cid:23) (cid:75) (cid:404)(cid:82)(cid:82)(cid:85)(cid:15)
the annual meeting, you will need to detach and retain the admission ticket attached to your proxy card mailed or emailed to you 
with the notice of the annual meeting and the proxy statement. As space is limited, you may bring only one guest to the meeting. 
If you hold your stock through a broker, bank or other nominee, please bring a legal proxy or other evidence to the meeting showing 
that you owned NW Natural Common Stock as of the record date, April 5, 2018, and we will provide you with an admission ticket. 
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(cid:68)(cid:81)(cid:71)(cid:71) (cid:83)(cid:85)(cid:82)(cid:91)(cid:92) (cid:86)(cid:87)(cid:68)(cid:87)(cid:72)(cid:80)(cid:72)(cid:81)(cid:87) (cid:90)(cid:76)(cid:79)(cid:79)(cid:76)(cid:79)(cid:79) (cid:69)(cid:72)(cid:69) (cid:86)(cid:72)(cid:81)(cid:87) (cid:87)(cid:82) (cid:68)(cid:79)(cid:79)(cid:79)(cid:79) (cid:86)(cid:75)(cid:68)(cid:85)(cid:72)(cid:75)(cid:82)(cid:79)(cid:71)(cid:72)(cid:85)(cid:86)

(cid:36) (cid:76)(cid:79) (cid:44)(cid:73)(cid:44)(cid:73) (cid:92)(cid:82)(cid:88) (cid:83)(cid:79)(cid:68)(cid:81)(cid:79)

(cid:76)(cid:81)(cid:76) (cid:36)(cid:83)(cid:85)(cid:76)(cid:79)(cid:17)

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Dividend reinvestment 
and direct stock purchase plan
Participants may make an initial invest-
ment in company stock and common
shareholders of record may reinvest all or 
part of their dividends in additional shares 
under the company’s plan. Cash purchases 
may also be made. Participants in the plan
bear the cost of brokerage fees and com-
missions for shares purchased on the open 
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(cid:36) (cid:83)(cid:85)(cid:82)(cid:86)(cid:83)(cid:72)(cid:70)(cid:87)(cid:88)(cid:86) (cid:90)(cid:76)(cid:79)(cid:79) (cid:69)(cid:72) (cid:86)(cid:72)(cid:81)(cid:87) (cid:88)(cid:83)(cid:82)(cid:81) (cid:85)(cid:72)(cid:84)(cid:88)(cid:72)(cid:86)(cid:87)(cid:17)

COMPARISON OF FIVE-YEAR
CUMULATIVE TOTAL RETURN
(Based on $100 invested on 12/31/2012)

$250

$200

$150

$100

$50

$0

2012

2013

2014

2015

2016

2017

NWN

S&P UTILITIES INDEX

S&P 500 INDEX

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years ending December 31, 2017 for NW Natural was 
(cid:20)(cid:19)(cid:17)(cid:21)(cid:19)(cid:8)(cid:15) (cid:70)(cid:82)(cid:80)(cid:83)(cid:68)(cid:85)(cid:72)(cid:71) (cid:87)(cid:82) (cid:54)(cid:87)(cid:68)(cid:81)(cid:71)(cid:68)(cid:85)(cid:71) (cid:9) (cid:51)(cid:82)(cid:82)(cid:85)(cid:267)(cid:86) (cid:11)(cid:54)(cid:9)(cid:51)(cid:12) (cid:56)(cid:87)(cid:76)(cid:79)(cid:76)(cid:87)(cid:76)(cid:72)(cid:86)
Index return of 12.61%, and the S&P 500 Index return 
of 15.77%.

Scheduled dividend payment dates
Subject to Board approval, the following
dates are scheduled for dividend payment:
February 15, 2018
May 15, 2018
August 15, 2018
November 15, 2018

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(cid:55)(cid:75)(cid:72) (cid:38)(cid:75)(cid:76)(cid:72)(cid:73) (cid:40)(cid:91)(cid:72)(cid:70)(cid:88)(cid:87)(cid:76)(cid:89)(cid:72) (cid:50)(cid:73)(cid:403)(cid:70)(cid:72)(cid:85) (cid:70)(cid:72)(cid:85)(cid:87)(cid:76)(cid:403)(cid:72)(cid:71) (cid:87)(cid:82) (cid:87)(cid:75)(cid:72)
NYSE on June 26, 2017, that as of that date, 
he was not aware of any violation by the 
company of NYSE’s corporate governance
listing standards, and the company had 
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(cid:38)(cid:82)(cid:80)(cid:80)(cid:76)(cid:86)(cid:86)(cid:76)(cid:82)(cid:81) (cid:11)(cid:54)(cid:40)(cid:38)(cid:12)(cid:15) (cid:68)(cid:86) (cid:72)(cid:91)(cid:75)(cid:76)(cid:69)(cid:76)(cid:87)(cid:86) (cid:22)(cid:20)(cid:17)(cid:20) (cid:68)(cid:81)(cid:71)
31.2 to its Annual Report on Form 10-K
for the year ended December 31, 2016,
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(cid:50)(cid:73)(cid:403)(cid:70)(cid:72)(cid:85) (cid:68)(cid:81)(cid:71) (cid:87)(cid:75)(cid:72) (cid:38)(cid:75)(cid:76)(cid:72)(cid:73) (cid:41)(cid:76)(cid:81)(cid:68)(cid:81)(cid:70)(cid:76)(cid:68)(cid:79) (cid:50)(cid:73)(cid:403)(cid:70)(cid:72)(cid:85) (cid:82)(cid:73)
(cid:87)(cid:75)(cid:72) (cid:70)(cid:82)(cid:80)(cid:83)(cid:68)(cid:81)(cid:92) (cid:70)(cid:72)(cid:85)(cid:87)(cid:76)(cid:73)(cid:92)(cid:76)(cid:81)(cid:74) (cid:87)(cid:75)(cid:72) (cid:84)(cid:88)(cid:68)(cid:79)(cid:76)(cid:87)(cid:92) (cid:82)(cid:73) (cid:87)(cid:75)(cid:72)
company’s public disclosure. For the year 
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(cid:82)(cid:73) (cid:87)(cid:75)(cid:72) (cid:38)(cid:75)(cid:76)(cid:72)(cid:73) (cid:40)(cid:91)(cid:72)(cid:70)(cid:88)(cid:87)(cid:76)(cid:89)(cid:72) (cid:50)(cid:73)(cid:403)(cid:70)(cid:72)(cid:85) (cid:68)(cid:81)(cid:71) (cid:38)(cid:75)(cid:76)(cid:72)(cid:73)
(cid:41)(cid:76)(cid:81)(cid:68)(cid:81)(cid:70)(cid:76)(cid:68)(cid:79) (cid:50)(cid:73)(cid:403)(cid:70)(cid:72)(cid:85) (cid:68)(cid:85)(cid:72) (cid:68)(cid:87)(cid:87)(cid:68)(cid:70)(cid:75)(cid:72)(cid:71) (cid:68)(cid:86) (cid:72)(cid:91)(cid:75)(cid:76)(cid:69)(cid:76)(cid:87)(cid:86)
31.1 and 31.2 to the Form 10-K included in
this Annual Report.

Contact the NW Natural Board
Concerns may be directed to the
nonmanagement directors by writing 
to NW Natural Board of Directors, 
c/o Corporate Secretary.  

Forward-looking statements
The statements made in this Annual
Report that are not purely historical,
including statements regarding plans, 
goals, strategies, success, opportunities, 
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demand or preference for gas, the future 
of clean energy and the role of natural 
gas in it, renewable natural gas, power to 
gas, commodity costs, customer rates and 
service, competitive position, revenues,
customer and business growth, capital 

expenditures, Mist storage expansion 
project, including but not limited to cost
and timelines, emergency preparedness, 
cybersecurity, system reliability, safety, 
environmental stewardship, regulatory 
proceedings and actions, including, but 
not limited to our rate case and the timing 
and results thereof, the regional economy,
expansion into the water sector, Gill Ranch
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multifamily sector, system modernization 
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reorganization as a holding company, and
effects of legislation, including the Federal 
Tax Cuts and Jobs Act, are forward-looking
statements within the “safe harbor” pro-
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(cid:53)(cid:72)(cid:73)(cid:82)(cid:85)(cid:80) (cid:36)(cid:70)(cid:87) (cid:82)(cid:73) (cid:20)(cid:28)(cid:28)(cid:24)(cid:17) (cid:49)(cid:58) (cid:49)(cid:68)(cid:87)(cid:88)(cid:85)(cid:68)(cid:79)(cid:267)(cid:86) (cid:68)(cid:70)(cid:87)(cid:88)(cid:68)(cid:79)
results could differ materially from those
anticipated in these forward-looking 
statements as a result of risks and uncer-
tainties, including those described in the 
attached report on Form 10-K. For a more 
complete description of these risks and 
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with the SEC on Forms 10-K and 10-Q.

Request for publications
The following publications may be obtained
without charge by contacting the Corporate
Secretary at NW Natural’s address: Annual 
Report; Form 10-K; Form 10-Q; Corporate 
Governance Standards; Director Indepen-
dence Standards; Code of Ethics; and Board
Committee Charters. These publications, 
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are also available on our website at nwnat-
(cid:88)(cid:85)(cid:68)(cid:79)(cid:17)(cid:70)(cid:82)(cid:80)(cid:17) (cid:50)(cid:88)(cid:85) (cid:54)(cid:40)(cid:38) (cid:403)(cid:79)(cid:76)(cid:81)(cid:74)(cid:86) (cid:68)(cid:85)(cid:72) (cid:68)(cid:79)(cid:86)(cid:82) (cid:68)(cid:89)(cid:68)(cid:76)(cid:79)(cid:68)(cid:69)(cid:79)(cid:72)
(cid:69)(cid:92) (cid:85)(cid:72)(cid:84)(cid:88)(cid:72)(cid:86)(cid:87) (cid:87)(cid:75)(cid:85)(cid:82)(cid:88)(cid:74)(cid:75) (cid:87)(cid:75)(cid:72) (cid:54)(cid:40)(cid:38) (cid:69)(cid:92) (cid:80)(cid:68)(cid:76)(cid:79) (cid:68)(cid:87) (cid:56)(cid:17)(cid:54)(cid:17)
Securities and Exchange Commission, 
(cid:50)(cid:73)(cid:403)(cid:70)(cid:72) (cid:82)(cid:73) (cid:41)(cid:50)(cid:44)(cid:36)(cid:18)(cid:51)(cid:36) (cid:50)(cid:83)(cid:72)(cid:85)(cid:68)(cid:87)(cid:76)(cid:82)(cid:81)(cid:86)(cid:15) (cid:20)(cid:19)(cid:19) (cid:41) (cid:54)(cid:87)(cid:85)(cid:72)(cid:72)(cid:87)(cid:15)
(cid:49)(cid:17)(cid:40)(cid:17)(cid:15) (cid:58)(cid:68)(cid:86)(cid:75)(cid:76)(cid:81)(cid:74)(cid:87)(cid:82)(cid:81)(cid:15) (cid:39)(cid:17)(cid:38)(cid:17) (cid:21)(cid:19)(cid:24)(cid:23)(cid:28)(cid:15) (cid:82)(cid:85) (cid:82)(cid:81)(cid:79)(cid:76)(cid:81)(cid:72) (cid:68)(cid:87)
sec.gov. You can obtain information about 
access to the Public Reference Room and 
(cid:75)(cid:82)(cid:90) (cid:87)(cid:82) (cid:68)(cid:70)(cid:70)(cid:72)(cid:86)(cid:86) (cid:82)(cid:85) (cid:85)(cid:72)(cid:84)(cid:88)(cid:72)(cid:86)(cid:87) (cid:85)(cid:72)(cid:70)(cid:82)(cid:85)(cid:71)(cid:86) (cid:69)(cid:92) (cid:70)(cid:68)(cid:79)(cid:79)(cid:76)(cid:81)(cid:74)
the SEC at 1-800-SEC-0330.

Produced by NW Natural’s Corporate Communications

PHOTO CREDITS ANDY BAUER - page 5, North Mist expansion pipeline; DALE HEADRICK - page 2, J.D. Power Awards; 
page 4, Training Town, System Operations; page 5, Customer Contact Center; page 6, Bill Edmonds and David Anderson; 
ROBBIE McCLARAN - page 3, David Anderson • PRINTING Donnelley Financial Solutions

10

Form 10-K
Annual Report

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 10-K

(Mark One)
[X]       ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2017
OR

[  ]       TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from ___________ to____________
Commission file number 1-15973

NORTHWEST NATURAL GAS COMPANY
(Exact name of registrant as specified in its charter) 

 Oregon 

(State or other jurisdiction of    

incorporation or organization)  

93-0256722

(I.R.S. Employer

Identification No.)

220 N.W. Second Avenue, Portland, Oregon 97209
(Address of principal executive offices)  (Zip Code)
Registrant’s telephone number, including area code:  (503) 226-4211

Securities registered pursuant to Section 12(b) of the Act:
Title of each class                                                                                   Name of each exchange on which registered
Common Stock                                                                                       New York Stock Exchange
Securities registered pursuant to Section 12(g) of the Act:  None.

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

Yes  [ X ]    No  [    ]

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.

Yes  [   ]    No  [ X ]

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the 
Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to 
file such reports), and (2) has been subject to such filing requirements for the past 90 days. 
Yes  [ X ]    No  [    ]

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every 

Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) 
during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). 
Yes [ X ]     No  [   ]

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405) is not contained 
herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated 
by reference in Part III of this Form 10-K or any amendment to this Form 10-K.[    ]

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a 
smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," 
"smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act. (Check one):
Large Accelerated Filer [ X ]                                                                      Accelerated Filer [    ]
Non-accelerated Filer [    ]                                                                         Smaller Reporting Company [    ]
Emerging Growth Company [    ]

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period 
for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.[    ]

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Yes  [   ]    No  [ X ]

As of June 30, 2017, the aggregate market value of the shares of Common Stock (based upon the closing price of these 

shares on the New York Stock Exchange on that date) held by non-affiliates was $1,695,121,435.

At February 16, 2018, 28,751,528 shares of the registrant’s Common Stock (the only class of Common Stock) were 

outstanding.

Portions of the Proxy Statement of the registrant, to be filed in connection with the 2018 Annual Meeting of Shareholders, are 
incorporated by reference in Part III.

DOCUMENTS INCORPORATED BY REFERENCE

NORTHWEST NATURAL GAS COMPANY
Annual Report to Securities and Exchange Commission on Form 10-K
For the Fiscal Year Ended December 31, 2017

TABLE OF CONTENTS

PART I

Glossary of Terms

Forward-Looking Statements

Item 1.

Business

Overview

 Local Gas Distribution "Utility"

 Gas Storage

 Other

Environmental Matters

Employees

Additions to Infrastructure

Executive Officers of the Registrant

Available Information

Item 1A. Risk Factors

Item 1B. Unresolved Staff Comments

Properties

Legal Proceedings

Mine Safety Disclosures

Item 2.

Item 3.

Item 4.

PART II

Item 5.

Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer

Item 6.

Item 7.

Purchases of Equity Securities

Selected Financial Data

Management’s Discussion and Analysis of Financial Condition and Results of Operations

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

Item 8.
Item 9.

Financial Statements and Supplementary Data

Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Item 9A. Controls and Procedures

Item 9B. Other Information

PART III

Item 10. Directors, Executive Officers and Corporate Governance

Item 11. Executive Compensation
Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13. Certain Relationships and Related Transactions, and Director Independence

Item 14. Principal Accountant Fees and Services

PART IV  

Item 15. Exhibits and Financial Statement Schedules

Item 16.

Form 10-K Summary

EXHIBIT INDEX

SIGNATURES

Page

1

3

4

4

4

8

11

11

12

12

12

12

14

23

24

24

24

25

26

27

52

54

91

91

91

92

93

93

94

94

94

94

95

100

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
GLOSSARY OF TERMS AND ABBREVIATIONS

AFUDC

Allowance for Funds Used During Construction

AOCI / AOCL

Accumulated Other Comprehensive Income (Loss)

ASC

ASU

Accounting Standards Codification

Accounting Standards Update as issued by the FASB

Average Weather

The 25-year average of heating degree days based on temperatures established in our last Oregon
general rate case

Bcf

CNG

Billion cubic feet, a volumetric measure of natural gas, where one Bcf is roughly equal to 10 million
therms

Compressed Natural Gas

Core Utility Customers Residential, commercial, and industrial customers receiving firm service from the utility

Cost of Gas

CPUC

Decoupling

Demand Cost

EBITDA

EE/CA

Encana

The delivered cost of natural gas sold to customers, including the cost of gas purchased or withdrawn/
produced from storage inventory or reserves, gains and losses from gas commodity hedges, pipeline
demand costs, seasonal demand cost balancing adjustments, regulatory gas cost deferrals and
Company gas use

California Public Utilities Commission, the entity that regulates our California gas storage business at
our Gill Ranch facility with respect to rates and terms of service, among other matters

A billing rate mechanism, also referred to as our conservation tariff, which is designed to allow the
utility to encourage industrial and small commercial customers to conserve energy while not adversely
affecting its earnings due to reductions in sales volumes

A component in core utility customer rates representing the cost of securing firm pipeline capacity,
whether the capacity is used or not
Earnings before interest, taxes, depreciation and amortization, a non-GAAP financial measure

Engineering Evaluation / Cost Analysis

Encana Oil & Gas (USA) Inc.

Energy Corp

Northwest Energy Corporation, a wholly-owned subsidiary of NW Natural

EPA

EPS

FASB

FERC

Firm Service

FMBs

GAAP

Environmental Protection Agency

Earnings per share

Financial Accounting Standards Board

Federal Energy Regulatory Commission; the entity regulating interstate storage services offered by
our Mist gas storage facility as part of our gas storage segment

Natural gas service offered to customers under contracts or rate schedules that will not be disrupted
to meet the needs of other customers

First Mortgage Bonds

Accounting principles generally accepted in the United States of America

General Rate Case

A periodic filing with state or federal regulators to establish billing rates for utility customers

GHG

Gill Ranch

Gill Ranch Facility

GTN

Greenhouse gases

Gill Ranch Storage, LLC, a wholly-owned subsidiary of NWN Gas Storage

Underground natural gas storage facility near Fresno, California, with 75% owned by Gill Ranch and
25% owned by PG&E

Gas Transmission Northwest, which owns a transmission pipeline serving California and the Pacific
Northwest

Heating Degree Days

Units of measure reflecting temperature-sensitive consumption of natural gas, calculated by
subtracting the average of a day’s high and low temperatures from 65 degrees Fahrenheit

HATFA

IBEW

Highway and Transportation Funding Act of 2014

International Brotherhood of Electrical Workers Local Union No. 1245, which is also referred to as the
Union formerly representing NW Natural's bargaining unit employees at Gill Ranch

Interruptible Service

Natural gas service offered to customers (usually large commercial or industrial users) under
contracts or rate schedules that allow for interruptions when necessary to meet the needs of firm
service customers

IRP

KB

LNG

Integrated Resource Plan

Kelso-Beaver Pipeline, of which 10% is owned by KB Pipeline Company, a subsidiary of NNG
Financial

Liquefied Natural Gas, the cryogenic liquid form of natural gas. To reach a liquid form at atmospheric
pressure, natural gas must be cooled to approximately negative 260 degrees Fahrenheit

1

MAP-21

Moody's

NAV

A federal pension plan funding law called the Moving Ahead for Progress in the 21st Century Act, July
2012

Moody's Investors Service, Inc., credit rating agency

Net Asset Value

NNG Financial

NNG Financial Corporation, a wholly-owned subsidiary of NW Natural

NOL

NRD

Net Operating Loss

Natural Resource Damages

NWN Energy

NW Natural Energy, LLC, a wholly-owned subsidiary of NW Natural

NWN Gas Reserves

NWN Gas Reserves LLC, a wholly-owned subsidiary of Northwest Energy Corporation

NWN Gas Storage

NW Natural Gas Storage, LLC, a wholly-owned subsidiary of NWN Energy

ODEQ

OPEIU

OPUC

PBGC

PG&E

PGA

PGE

PHMSA

PRP

RI/FS

ROD

ROE

ROR

S&P

Oregon Department of Environmental Quality

Office and Professional Employees International Union Local No. 11, AFL-CIO, which is also referred
to as the Union representing NW Natural's bargaining unit employees

Public Utility Commission of Oregon; the entity that regulates our Oregon utility business with respect
to rates and terms of service, among other matters; the OPUC also regulates our Mist gas storage
facility's intrastate storage services

Pension Benefit Guaranty Corporation

Pacific Gas & Electric Company; 25% owner of the Gill Ranch Facility

Purchased Gas Adjustment, a regulatory mechanism which adjusts customer rates to reflect changes
in the forecasted cost of gas and differences between forecasted and actual gas costs from the prior
year

Portland General Electric; primary customer of the North Mist gas storage expansion

U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration

Potentially Responsible Parties

Remedial Investigation / Feasibility Study

Record of Decision

Return on Equity, a measure of corporate profitability, calculated as net income or loss divided by
average common stock equity. Authorized ROE refers to the equity rate approved by a regulatory
agency for use in determining utility revenue requirements

Rate of Return, a measure of return on utility rate base. Authorized ROR refers to the rate of return
approved by a regulatory agency and is generally discussed in the context of ROE and capital
structure

Standard & Poor's, a credit rating agency and division of The McGraw-Hill Companies, Inc.

Sales Service

Service provided whereby a customer purchases both natural gas commodity supply and
transportation from the utility

SEC

SRRM

TAIL

TCJA

Therm

TWH

TWP

U.S. Securities and Exchange Commission

Site Remediation and Recovery Mechanism, a billing rate mechanism for recovering prudently
incurred environmental site remediation costs allocable to Oregon through customer billings, subject
to an earnings test

TransCanada American Investments, Ltd., a 50% owner of TWH

H.R.1; An act to provide for reconciliation pursuant to titles II and V of the concurrent resolution on the
budget for fiscal year 2018, also known as the Tax Cuts and Jobs Act enacted on December 22, 2017

The basic unit of natural gas measurement, equal to one hundred thousand Btu’s

Trail West Holdings, LLC, 50% owned by NWN Energy

Trail West Pipeline, LLC, a subsidiary of TWH

TransCanada

TransCanada Pipelines Limited, owner of TAIL and GTN

Transportation Service Service provided whereby a customer purchases natural gas directly from a supplier but pays the

utility to transport the gas over its distribution system to the customer’s facility

Utility Margin

A financial measure consisting of utility operating revenues less the associated cost of gas, franchise
taxes, and environmental recoveries

WARM

WUTC

An Oregon billing rate mechanism applied to residential and commercial customers to adjust for
temperature variances from average weather

Washington Utilities and Transportation Commission, the entity that regulates our Washington utility
business with respect to rates and terms of service, among other matters

2

FORWARD-LOOKING STATEMENTS

This report contains forward-looking statements within the 
meaning of the U.S. Private Securities Litigation Reform Act 
of 1995, which are subject to the safe harbors created by 
such Act. Forward-looking statements can be identified by 
words such as anticipates, assumes, intends, plans, seeks, 
believes, estimates, expects, and similar references to future 
periods. Examples of forward-looking statements include, 
but are not limited to, statements regarding the following:
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 

plans, projections and predictions;
objectives, goals or strategies;
assumptions, generalizations and estimates;
ongoing continuation of past practices or patterns;
future events or performance;
trends;
risks;
timing and cyclicality;
earnings and dividends;
capital expenditures and allocation; 
capital or organizational structure, including restructuring 
as a holding company;
climate change and our role in a low-carbon future;
growth;
customer rates;
labor relations and workforce succession;
commodity costs;
gas reserves;
operational performance and costs;
energy policy, infrastructure and preferences;
public policy approach and involvement;
efficacy of derivatives and hedges;
liquidity,  financial  positions,  and  planned  securities 
issuances;
valuations;
project and program development, expansion, or 
investment;
business development efforts, including acquisitions and 
integration thereof;
pipeline capacity, demand, location, and reliability;
adequacy of property rights and headquarter 
development;
technology implementation and cybersecurity practices;
competition;
procurement and development of gas supplies;
estimated expenditures;
costs of compliance;
credit exposures;
rate or regulatory outcomes, recovery or refunds;
impacts or changes of laws, rules and regulations;
tax liabilities or refunds, including effects of tax reform;
levels and pricing of gas storage contracts and gas 
storage markets;
outcomes, timing and effects of potential claims, 
litigation, regulatory actions, and other administrative 
matters;
projected  obligations,  expectations  and  treatment  with 
respect to retirement plans;
availability, adequacy, and shift in mix, of gas supplies;
effects of new or anticipated changes in critical accounting 
policies or estimates; 
approval and adequacy of regulatory deferrals;
effects and efficacy of regulatory mechanisms; and
environmental, regulatory, litigation and insurance costs 
and recoveries, and timing thereof.

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 

• 
• 

• 

• 
• 

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 

• 

• 

• 
• 

• 
• 
• 

Forward-looking statements are based on our current 
expectations and assumptions regarding our business, the 
economy, and other future conditions. Because forward-
looking statements relate to the future, they are subject to 
inherent uncertainties, risks, and changes in circumstances 
that are difficult to predict. Our actual results may differ 
materially from those contemplated by the forward-looking 
statements. We therefore caution you against relying on any 
of these forward-looking statements. They are neither 
statements of historical fact nor guarantees or assurances of 
future performance. Important factors that could cause 
actual results to differ materially from those in the forward-
looking statements are discussed at Item 1A., "Risk Factors" 
of Part I and Item 7. and Item 7A., "Management’s 
Discussion and Analysis of Financial Condition and Results 
of Operations" and "Quantitative and Qualitative Disclosures 
About Market Risk", respectively, of Part II of this report.

Any forward-looking statement made by us in this report 
speaks only as of the date on which it is made. Factors or 
events that could cause our actual results to differ may 
emerge from time to time, and it is not possible for us to 
predict all of them. We undertake no obligation to publicly 
update any forward-looking statement, whether as a result of 
new information, future developments or otherwise, except 
as may be required by law.

3

 
NORTHWEST NATURAL GAS 
COMPANY
PART I

ITEM 1. BUSINESS

OVERVIEW

Northwest Natural Gas Company (NW Natural or the 
Company) was incorporated under the laws of Oregon in 
1910. Our Company and its predecessors have supplied 
gas service to the public since 1859, and we have been 
doing business as NW Natural since 1997. We maintain 
operations in Oregon, Washington, and California and 
conduct business through NW Natural and its subsidiaries. 
References in this discussion to "Notes" are to the Notes to 
the Consolidated Financial Statements in Item 8 of this 
report.

We have two core businesses: our regulated local gas 
distribution business, referred to as the utility segment, 
which serves residential, commercial, and industrial 
customers in Oregon and southwest Washington; and our 
gas storage businesses, referred to as the gas storage 
segment, which provides storage services for utilities, gas 
marketers, electric generators, and large industrial users 
from storage facilities located in Oregon and California. In 
addition, we have investments and other non-utility activities 
we aggregate and report as other. See Note 4 for further 
information.

The utility business is our largest segment, while our gas 
storage business accounts for the majority of our remaining 
net income or loss. The following table reflects the allocation 
between segments and other as of December 31, 2017:

Non-Utility(1)

Gas 

$

59.6

Total

Utility

Storage(2) Other

$ 2,961.3

In millions
Assets(3)
Net income (loss)(3)
(1)  We refer to our gas storage segment and other as non-utility 
as they are not included in our regulated gas distribution 
business; however, certain aspects of the gas storage 
segment and other may be regulated by the OPUC, WUTC, 
CPUC, or FERC. 

(116.2)

$ 18.8

60.5

0.1

$ 3,039.7

(55.6)

(2)   Our gas storage segment includes asset management 

services for both the utility and non-utility portion of our Mist 
gas storage facility. 

(3)   Our assets and net loss include an impairment of long-lived 
assets at the Gill Ranch Facility of $192.5 million and $141.5 
million, respectively. See Part II, Item 7, "Application of Critical 
Accounting Policies and Estimates—Impairment of Long-Lived 
Assets."

LOCAL GAS DISTRIBUTION "UTILITY"

The utility is principally engaged in the regulated distribution 
of natural gas in Oregon and southwest Washington to over 
735,000 customers with approximately 89% of our 
customers located in Oregon and 11% located in 
Washington. In total, we provide natural gas service to over 
100 cities in 18 counties with an estimated population of 3.7 
million in our service territory.

4

We have been allocated an exclusive service territory by the 
OPUC and WUTC, which includes a major portion of 
western Oregon, including the Portland metropolitan area, 
most of the Willamette Valley, the Coastal area from Astoria 
to Coos Bay, and portions of Washington along the 
Columbia River. Portland serves as one of the largest 
international ports on the West Coast and is a key 
distribution center due to its comprehensive transportation 
system of ocean and river shipping, transcontinental 
railways and highways, and an international airport. Major 
businesses located in our service territory include retail, 
manufacturing, and high-technology industries. 

Customers
We serve residential, commercial, and industrial customers 
with no individual customer or industry accounting for more 
than 10% of our utility revenues. On an annual basis, 
residential and commercial customers typically account for 
55% to 60% of our utility’s total volumes delivered and 90% 
of our utility’s margin. Industrial customers largely account 
for the remaining volumes and utility margin. 

The following table presents summary customer information 
as of December 31, 2017:

Residential

Commercial

Industrial

Other

Total

Number of
Customers

% of
Volumes

% of Utility 
Margin (1)

668,803

68,050

1,021

N/A

38%

22%

40%

N/A

63%

28%

8%

1%

737,874

100%

100%

(1)   Utility margin is also affected by other items, including 

miscellaneous services, gains or losses from our gas cost 
incentive sharing mechanism, and other service fees. 

Generally, residential and commercial customers purchase 
both their natural gas commodity (gas sales) and natural 
gas delivery services (transportation services) from the 
utility. Industrial customers also purchase transportation 
services from the utility, but may buy the gas commodity 
either from the utility or directly from a third-party gas 
marketer or supplier. Our gas commodity cost is primarily a 
pass-through cost to customers; therefore, our profit 
margins are not materially affected by an industrial 
customer's decision to purchase gas from us or from third 
parties. Industrial and large commercial customers may also 
select between firm and interruptible service levels, with firm 
services generally providing higher profit margins compared 
to interruptible services.

To help manage gas supplies, our industrial tariffs are 
designed to provide some certainty regarding industrial 
customers' volumes by requiring an annual service election, 
special charges for changes between elections, and in some 
cases, a minimum or maximum volume requirement before 
changing options. 

Customer growth rates for natural gas utilities in the Pacific 
Northwest historically have been among the highest in the 
nation due to lower market saturation as natural gas 
became widely available as a residential heating source 
after other fuel options. We estimate natural gas was in 
approximately 63% of single-family residential homes in 

  
both 2017 and 2016 using our in-house system mapping 
technology. Customer growth in our region comes from the 
following main sources: single-family housing, both new 
construction and conversions; multifamily housing new 
construction; and commercial buildings, both new 
construction and conversions. Single-family new 
construction has consistently been our strongest performing 
source of growth. Continued customer growth is closely tied 
to the comparative price of natural gas to electricity and fuel 
oil and the health of the Portland, Oregon and Vancouver, 
Washington economies. We believe there is potential for 
continued growth as natural gas is a preferred energy 
source due to its affordable, reliable, and clean qualities. 

Competitive Conditions
In our service areas, we have no direct competition from 
other natural gas distributors, but we compete with other 
forms of energy in each customer class. This competition 
among energy suppliers is based on price, efficiency, 
reliability, performance, preference, market conditions, 
technology, federal, state, and local energy policy, and 
environmental impacts. 

For residential and small to mid-size commercial customers, 
we compete primarily with providers of electricity, fuel oil, 
and propane.

In the industrial and large commercial markets, we compete 
with all forms of energy, including competition from 
wholesale natural gas marketers. In addition, large industrial 
customers could bypass our local gas distribution system by 
installing their own direct pipeline connection to the 
interstate pipeline system. We have designed custom 
transportation service agreements with several of our 
largest industrial customers to provide transportation service 
rates that are competitive with the customer’s costs of 
installing their own pipeline; these agreements generally 
prohibit bypass. Due to the cost pressures confronting a 
number of our largest customers competing in global 
markets, bypass continues to be a competitive 
threat. Although we do not expect a significant number of 
our large customers to bypass our system in the 
foreseeable future, we could experience deterioration of 
utility margin if customers bypass or switch over to custom 
contracts with lower profit margins.

Seasonality of Business
Our utility business is seasonal in nature due to higher gas 
usage by residential and commercial customers during the 
cold winter heating months. Our other categories of 
customers experience seasonality in their usage but to a 
lesser extent.

Regulation and Rates
The utility is subject to regulation by the OPUC, WUTC, and 
FERC. These regulatory agencies authorize rates and allow 
recovery mechanisms to provide our utility the opportunity to 
recover prudently incurred capital and operating costs from 
customers, while also earning a reasonable return on 
investment for investors. In addition, the OPUC and WUTC 
also regulate the system of accounts and issuance of 
securities by our utility.

We file general rate cases and rate tariff requests 

5

periodically with the commissions to establish approved 
rates, an authorized ROE, an overall rate of return on rate 
base (ROR), an authorized utility capital structure, and other 
revenue/cost deferral and recovery mechanisms. 

In addition, under our Mist interstate storage certificate with 
FERC, the utility is required to file either a petition for rate 
approval or a cost and revenue study every five years to 
change or justify maintaining the existing rates for the 
interstate storage service. 

For further discussion on our most recent general rate 
cases, see Part II, Item 7, "Results of Operations—
Regulatory Matters—Regulation and Rates".

Gas Supply
The utility strives to secure sufficient, reliable supplies of 
natural gas to meet the needs of customers at the lowest 
reasonable cost, while maintaining price stability and 
managing gas purchase costs prudently. This is 
accomplished through a comprehensive strategy focused on 
the following items:
•  Reliability - ensuring gas resource portfolios are 
sufficient to satisfy customer requirements under 
extreme cold weather conditions;

•  Diverse Supply - providing diversity of supply sources;
•  Diverse Contracts - maintaining a variety of contract 

durations, types, and counterparties; and 

•  Cost Management and Recovery - employing prudent 

gas cost management strategies. 

Reliability
The effectiveness of our gas distribution system ultimately 
rests on whether we provide reliable service to our core 
utility customers. To ensure our effectiveness, we develop a 
composite design year, including a seven-day design peak 
event based on the most severe cold weather experienced 
during the last 30 years in our service territory. 

Our projected maximum design day firm utility customer 
sendout is approximately 9.7 million therms. Of this total, we 
are currently capable of meeting about 57% of our 
maximum design day requirements with gas from storage 
located within or adjacent to our service territory, while the 
remaining supply requirements would come from gas 
purchases under firm gas purchase contracts and recall 
agreements. 

To supplement near-term natural gas supplies, we can 
segment transportation capacity during the heating seasons, 
if needed. Pipeline segmentation is a natural gas 
transportation mechanism under which a shipper can 
leverage its firm pipeline transportation capacity by 
separating it into multiple segments with alternate delivery 
routes. The reliability of service on these alternate routes 
will vary depending on the constraints of the pipeline 
system. For those segments with acceptable reliability, 
segmentation provides a shipper with increased flexibility 
and potential cost savings compared to traditional pipeline 
service. During the 2016-2017 and 2017-2018 heating 
seasons, we segmented and relied on approximately 0.6 
million therms per day of our firm pipeline transportation 
capacity that flowed from Stanfield, Oregon to various points 
south of Molalla, Oregon. 

We believe our gas supplies would be sufficient to meet 
existing firm customer demand if we were to experience 
maximum design day weather conditions. We will continue 
to evaluate and update our forecasted requirements and 
incorporate changes in our IRP process.  

The following table shows the sources of supply projected to 
be used to satisfy the design day sendout for the 2017-2018 
winter heating season:

We supplement our firm gas supply purchases with gas 
withdrawals from gas storage facilities, including 
underground reservoirs and LNG storage facilities. Storage 
facilities are generally injected with natural gas during the 
off-peak months in the spring and summer and the gas is 
withdrawn for use during peak demand months in the winter. 

The following table presents the storage facilities available 
for our utility supply:

 Therms in millions

Sources of utility supply:

Firm supply purchases

Mist underground storage (utility only)

Company-owned LNG storage

Off-system storage contract

Pipeline segmentation capacity

Recall agreements

Total

Therms

Percent

3.4

3.1

1.9

0.5

0.6

0.4

9.9

34%

32

19

5

6

4

100%

The OPUC and WUTC have IRP processes in which utilities 
define different growth scenarios and corresponding 
resource acquisition strategies in an effort to evaluate 
supply and demand resource requirements, consider 
uncertainties in the planning process and the need for 
flexibility to respond to changes, and establish a plan for 
providing reliable service at the least cost.

We file a full IRP biennially for Oregon and Washington with 
the OPUC and the WUTC, respectively, and file updates 
between filings. The OPUC acknowledges the Company's 
action plan; whereas the WUTC provides notice that our IRP 
has met the requirements of the Washington Administrative 
Code. OPUC acknowledgment of the IRP does not 
constitute ratemaking approval of any specific resource 
acquisition strategy or expenditure. However, the 
Commissioners generally indicate that they would give 
considerable weight in prudence reviews to utility actions 
consistent with acknowledged plans. The WUTC has 
indicated the IRP process is one factor it will consider in a 
prudence review.  For additional information see Part II, Item 
7, "Results of Operations—Regulatory Matters".

Diversity of Supply Sources 
We purchase our gas supplies primarily from the Alberta 
and British Columbia areas of Canada and multiple receipt 
points in the U.S. Rocky Mountains to protect against 
regional supply disruptions and to take advantage of price 
differentials. For 2017, 59% of our gas supply came from 
Canada, with the balance primarily coming from the U.S. 
Rocky Mountain region. We believe gas supplies available 
in the western United States and Canada are adequate to 
serve our core utility requirements for the foreseeable 
future. We continue to evaluate the long-term supply mix 
based on projections of gas production and pricing in the 
U.S. Rocky Mountain region as well as other regions in 
North America; however, we believe the cost of natural gas 
coming from western Canada and the U.S. Rocky Mountain 
region will continue to track with broader U.S. market 
pricing. Additionally, the extraction of shale gas has 
increased the availability of gas supplies throughout North 
America for the foreseeable future.

6

Gas Storage Facilities

Owned Facility

Mist, Oregon(1)

Contracted Facilities

Jackson Prairie, Washington(2)
Alberta, Canada(3)

LNG Facilities

Owned Facilities

Newport, Oregon

Portland, Oregon

Total

Maximum 
Daily 
Deliverability 
(therms in 
millions)

Designed 
Storage
Capacity 
(Bcf)

3.1

0.5

0.3

0.6

1.3

5.8

10.6

1.1

1.5

1.0

0.6

14.8

(1)   The Mist gas storage facility has a total maximum daily 

deliverability of 5.4 million therms and a total designed storage 
capacity of about 16 Bcf, of which 3.1 million therms of daily 
deliverability and 10.6 Bcf of storage capacity are reserved for 
core utility customers. 

(2)   The storage facility is located near Chehalis, Washington and 
is contracted from Northwest Pipeline, a subsidiary of The 
Williams Companies.

(3)   This resource does not add to our total peak day capacity, but 
mitigates price risks as it displaces equivalent volumes of 
heating season spot purchases. 

The Mist facility is used for both utility and non-utility 
purposes. Under our regulatory agreements with the OPUC 
and WUTC, non-utility gas storage at Mist can be developed 
in advance of core utility customer needs but is subject to 
recall by the utility when needed to serve utility customers 
as their demand increases. In 2017, the utility did not recall 
additional deliverability or associated storage capacity from 
the non-utility business to serve core utility customer needs.  

In addition, we have the ability to recall pipeline capacity 
and supply resources from certain customers if needed to 
meet high demand requirements.

Diverse Contract Durations and Types
We have a diverse portfolio of short-, medium-, and long-
term firm gas supply contracts and a variety of contract 
types including firm and interruptible supplies as well as 
supplemental supplies from gas storage facilities. 

Our portfolio of firm gas supply contracts typically includes 
the following gas purchase contracts: year-round and 
winter-only baseload supplies; seasonal supply with an 
option to call on additional daily supplies during the winter 
heating season; and daily or monthly spot purchases.

During 2017, we purchased a total of 857 million therms 
under contracts with durations outlined in the chart below:

Contract Duration (primary term)

Long-term (one year or longer)

Short-term (more than one month, less than one
year)

Spot (one month or less)

Total

Percent of
Purchases

26%

23

51

100%

We renew or replace gas supply contracts as they expire. 
During 2017, no individual supplier provided over 10% of 
our gas supply requirements. 

Gas Cost Management
The cost of gas sold to utility customers primarily consists of 
the following items, which are included in annual PGA rates: 
gas purchases from suppliers; charges from pipeline 
companies to transport gas to our distribution system; gas 
storage costs; gas reserves contracts; and gas commodity 
derivative contracts.

We employ a number of strategies to mitigate the cost of 
gas sold to utility customers. Our primary strategies for 
managing gas commodity price risk include:
• 
• 

negotiating fixed prices directly with gas suppliers;
negotiating financial derivative contracts that: (1) 
effectively convert floating index prices in physical gas 
supply contracts to fixed prices (referred to as 
commodity price swaps); or (2) effectively set a ceiling 
or floor price, or both, on floating index priced physical 
supply contracts (referred to as commodity price 
options such as calls, puts, and collars). See Part II, 
Item 7A, "Quantitative and Qualitative Disclosures 
About Market Risk—Credit Risk—Credit Exposure to 
Financial Derivative Counterparties";
buying physical gas supplies at a set price and injecting 
the gas into storage for price stability and to minimize 
pipeline capacity demand costs; and
investing in gas reserves for longer term price stability. 
See Note 11 for additional information about our gas 
reserves.

• 

• 

We also contract with an independent energy marketing 
company to capture opportunities regarding our storage and 
pipeline capacity when those assets are not serving the 
needs of our core utility customers. Our asset management 
activities provide opportunities for cost of gas savings for 
our customers and incremental revenues for our 
shareholders through a regulatory incentive-sharing 
mechanism. These activities are included in our gas storage 
segment.

Gas Cost Recovery
Mechanisms for gas cost recovery are designed to be fair 
and reasonable, with an appropriate balance between the 
interests of our customers and shareholders. In general, 
utility rates are designed to recover the costs of, but not to 
earn a return on, the gas commodity sold. We minimize risks 
associated with gas cost recovery by resetting customer 
rates annually through the PGA and aligning customer and 
shareholder interests through the use of sharing, weather 
normalization, and conservation mechanisms in Oregon. 

7

See Part II, Item 7, "Results of Operations—Regulatory 
Matters" and "Results of Operations—Business Segments—
Local Gas Distribution Utility Operations—Cost of Gas."

Transportation of Gas Supplies
Our local gas distribution system is reliant on a single, bi-
directional interstate transmission pipeline to bring gas 
supplies into our distribution system. Although we are 
dependent on a single pipeline, the pipeline’s gas flows into 
the Portland metropolitan market from two directions: (1) the 
north, which brings supplies from the British Columbia and 
Alberta supply basins; and (2) the east, which brings 
supplies from Alberta as well as the U.S. Rocky Mountain 
supply basins. 

We incur monthly demand charges related to our firm 
pipeline transportation contracts. These contracts are multi-
year contracts with expirations ranging from 2018 to 2060. 
Our largest pipeline agreements are with Northwest 
Pipeline. We actively work with Northwest Pipeline and 
others to renew contracts in advance of expiration to ensure 
gas transportation capacity is sufficient to meet our utility 
needs. 

Rates for interstate pipeline transportation services are 
established by FERC within the U.S. and by Canadian 
authorities for services on Canadian pipelines.

As mentioned above, our service territory is dependent on a 
single pipeline for its natural gas supply. Although supply 
has not been disrupted in the recent past, pipeline 
replacement projects and long-term projected natural gas 
demand in our region underscore the need for pipeline 
transportation diversity. In addition, there are potential 
industrial projects in the region, which could increase the 
demand for natural gas and the need for additional pipeline 
capacity and pipeline diversity. 

Currently, there are various interstate pipeline projects 
proposed, including the Trail West pipeline in which we have 
an interest, that could meet the forecasted demand for us 
and the region. However, the location of any future pipeline 
project will likely depend on the location of committed 
industrial projects. We will continue to evaluate and closely 
monitor the currently prospected projects to determine the 
best option for our customers. We have an equity 
investment in Trail West Holdings, LLC (TWH) that is 
developing plans to build the Trail West pipeline. This 
pipeline would connect TransCanada Pipelines Limited’s 
(TransCanada) Gas Transmission Northwest (GTN) 
interstate transmission line to our local gas distribution 
system. If constructed, this pipeline would provide another 
transportation path for gas purchases from Alberta and the 
U.S. Rocky Mountains in addition to the one that currently 
moves gas through the Northwest Pipeline system. 

Gas Distribution
The primary goals of our gas distribution operations are 
safety and reliability of our system, which entails building 
and maintaining a safe pipeline distribution system. 

Safety and the protection of our employees, our customers, 
and the public at large are, and will remain, our top 
priorities. We construct, operate, and maintain our pipeline 
distribution system and storage operations with the goal of 

ensuring natural gas is delivered and stored safely, reliably, 
and efficiently. 

NW Natural has one of the most modern distribution 
systems in the country with no identified cast iron pipe or 
bare steel main. We removed the final known bare steel 
from our system in 2015 and completed our cast iron pipe 
removal in 2000. Since the 1980s, we have taken a 
proactive approach to replacement programs and partnered 
with our Commissions on progressive regulation to further 
safety and reliability efforts for our distribution system. In the 
past, we had a cost recovery program in Oregon that 
encompassed our programs for bare steel replacement, 
transmission pipeline integrity management, and distribution 
pipeline integrity management. If we want to have future 
cost recovery programs, we would have to seek PUC 
approval. For discussion on current regulatory programs, 
see Part II, Item 7, "Results of Operations—Regulatory 
Matters". 

Natural gas distribution businesses will continue to be 
subject to greater federal and state regulation in the future 
due to pipeline incidents involving other companies. 
Additional operating and safety regulations from the U.S. 
Department of Transportation’s Pipeline and Hazardous 
Materials Safety Administration (PHMSA) are currently 
under development. In 2016, PHMSA issued proposed 
regulations to update safety requirements for natural gas 
transmission pipelines. The final draft of these regulations is 
anticipated to be issued by the end of 2018, with final 
regulations anticipated to be issued in 2019. Current 
proposed regulations indicate a 15-year timeline for 
implementation of compliance requirements. We will 
continue to work diligently with industry associations as well 
as federal and state regulators to ensure the safety of our 
system and compliance with new laws and regulations. We 
expect the costs to our utility associated with compliance 
with federal, state, and local rules would be recoverable in 
rates.

North Mist Gas Storage Expansion Project
In Oregon, there is a need to integrate intermittent 
resources, such as wind and solar, into the power system 
with policymakers committing to the elimination of coal-fired 
electric generation and moving toward a 50% renewable 
electricity standard by 2040. New, flexible natural gas-fired 
electric generation facilities and associated gas storage are 
necessary to support the integration of renewable 
resources. In 2016, we began expanding our gas storage 
facility near Mist, Oregon to provide innovative long-term, 
no-notice underground gas storage service to support gas-
fired electric generating facilities that are intended to 
facilitate the integration of more wind power into the region's 
electric generation mix. Natural gas storage enables 
generation to adjust quickly when renewable energy, such 
as wind and solar, rises and falls. 

This expansion project will be dedicated solely to Portland 
General Electric (PGE), a local electric company, to support 
their gas-fired electric power generation facilities under an 
initial 30-year contract with options to extend, totaling up to 
an additional 50 years upon mutual agreement of the 
parties. 

The expansion project includes a new reservoir providing up

to 2.5 Bcf of available storage, an additional compressor 
station with design capacity of 120,000 decatherms of gas 
per day, no-notice service that can be drawn on rapidly, and 
a 13-mile pipeline to connect to PGE's gas plants at Port 
Westward. The expansion project is considered part of the 
utility segment and has an estimated cost of approximately 
$132 million, with a targeted in-service date of the winter of 
2018-19. See additional discussion in Part II, Item 7 
"Financial Condition—Cash Flows—Investing Activities". 

When the expansion is placed into service, the investment 
will immediately be included in rate base under an 
established tariff schedule already approved by the OPUC, 
with revenues recognized consistent with the schedule. 
Billing rates will be updated annually to the current 
depreciable asset level and forecasted operating expenses.

GAS STORAGE

Our gas storage segment includes the following:
• 

the non-utility portion of the Mist gas storage facility 
near Mist, Oregon;
the Gill Ranch Facility near Fresno, California; and
asset management services provided by an 
independent energy marketing company. 

• 
• 

In general, the supply of natural gas remains relatively 
stable over the course of a year, while the demand for 
natural gas typically fluctuates seasonally. Storage facilities 
allow customers to purchase and inject natural gas supplies 
during periods of low demand and withdraw these supplies 
for use or resale during periods of higher demand. These 
facilities allow us to capitalize on the imbalance of supply 
and demand and price volatility for natural gas. 

For more information on gas storage assets and results of 
operations, see Note 4 and Part II, Item 7, "Financial 
Condition—Capital Structure—Liquidity and Capital 
Resources".

Gas Storage Facilities
The following table provides information concerning our 
non-utility gas storage facilities:

Maximum

Designed 
Storage
Capacity 
(Bcf)

Deliverability
(Therms in 
millions/day(3)

Injection
(Therms in 
millions/day)(3)

Mist Storage(1)

5.4

2.3

0.8

Gill Ranch Storage(2)
2.4
15.0
(1)   Approximately 5.4 Bcf of a total designed storage capacity of 
about 16 Bcf at Mist is currently available to our gas storage 
segment. The remaining 10.6 Bcf is used to provide gas 
storage for our local distribution business and its utility 
customers. 

4.9

(2)   Our gas storage segment share of the Gill Ranch Facility is 

currently 15 Bcf out of a total capacity of 20 Bcf.
(3)   Our gas storage segment share of the designed daily 

maximum injection and deliverability rates.

In addition to the designed storage capacity described 
above, capacity may incrementally increase based on 
variations in the heat content of the stored gas. All storage 
capacity and daily deliverability currently developed for the 
gas storage segment at Mist is available for recall by the 

8

utility. In 2015, the utility recalled approximately 0.3 million 
therms per day of deliverabiility and 0.7 Bcf of capacity for 
core utility customer use. There were no recalls by the utility 
in 2016 and 2017.

Mist Storage Facility
The Mist storage facility began operations in 1989. It is a 16 
Bcf facility with 5.4 Bcf available for use in our gas storage 
segment. The remaining 10.6 Bcf is used to provide gas 
storage for our local distribution business and its utility 
customers. Excluding the North Mist expansion, the facility 
consists of seven depleted natural gas reservoirs, 22 
injection and withdrawal wells, a compressor station, 
dehydration and control equipment, gathering lines, and 
other related facilities.

SERVICES. Mist provides multi-cycle gas storage services to 
customers in the interstate and intrastate markets from the 
facility located in Columbia County, Oregon, near the town 
of Mist. The Mist field was initially converted to storage 
operations for our utility customers. Since 2001, gas storage 
capacity at Mist has also been made available to interstate 
customers by developing new incremental capacity in 
advance of core utility customer requirements to meet the 
demands for interstate storage service. These interstate 
storage services are offered under a limited jurisdiction 
blanket certificate issued by FERC. In addition, since 2005 
we have offered intrastate firm storage services in Oregon 
under an OPUC-approved rate schedule as an optional 
service to eligible non-residential utility customers. 

CUSTOMERS. For Mist storage services, firm service 
agreements with customers are entered into with terms 
typically ranging from 1 to 10 years. Currently, our gas 
storage revenues from Mist are derived primarily from firm 
service customers who provide energy-related services, 
including natural gas distribution, electric generation, and 
energy marketing. Four storage customers currently account 
for all of our existing contracted non-utility gas storage 
capacity at Mist, with the largest customer accounting for 
about half of the total capacity. These four customers have 
contracts expiring at various dates through 2024. 

COMPETITIVE CONDITIONS. Our Mist gas storage facility 
benefits from limited competition from other Pacific 
Northwest storage facilities primarily because of its 
geographic location. However, competition from other 
storage providers in Washington and Canada, as well as 
competition for interstate pipeline capacity, does exist. In the 
future, we could face increased competition from new or 
expanded gas storage facilities as well as from new natural 
gas pipelines, marketers, and alternative energy sources. 

SEASONALITY. Mist gas storage revenues generally do not 
follow seasonal patterns similar to those experienced by the 
utility because most of the storage capacity is contracted 
with customers for firm service, which are primarily in the 
form of fixed monthly reservation charges and are not 
affected by customer usage. However, there is seasonal 
variation with Mist storage capacity and deliverability usage 
related to customers' lower demand during the spring and 
summer months, which can be optimized under regulatory 
sharing agreements with the OPUC and WUTC. For 
additional discussion, see "Asset Management" below.

9

REGULATION. Our Mist facility is subject to regulation by the 
OPUC and WUTC. In addition, FERC has approved 
maximum cost-based rates under our Mist interstate storage 
certificate. We are required to file either a petition for rate 
approval or a cost and revenue study with FERC at least 
every five years to change or justify maintaining the existing 
rates for the interstate storage service. For additional 
regulation and rates discussion, see Part II, Item 7, "Results 
of Operations—Regulatory Matters".

EXPANSION OPPORTUNITIES. We are currently expanding 
our Mist Storage facility to provide 2.5 Bcf of storage to a 
local electric company. For additional discussion, see "Local 
Gas Distribution Company—North Mist Gas Storage 
Expansion Project" above. While there are additional 
expansion opportunities in the Mist storage field, further 
development is not contemplated at this time and expansion 
would be based on market demand, project execution, cost 
effectiveness, available financing, receipt of future permits, 
and other rights.

Gill Ranch Storage Facility
Gill Ranch Storage, LLC (Gill Ranch), our subsidiary, has a 
joint project agreement with Pacific Gas and Electric 
Company (PG&E) governing the development and 
ownership of the Gill Ranch Facility, an underground natural 
gas storage facility near Fresno, California. Currently, Gill 
Ranch is the sole operator of the facility. The facility began 
operations in 2010 and consists of three depleted natural 
gas reservoirs, 12 injection and withdrawal wells, a 
compressor station, dehydration and control equipment, 
gathering lines, an electric substation, a natural gas 
transmission pipeline extending 27 miles from the storage 
field to an interconnection with the PG&E transmission 
system, and other related facilities. Gill Ranch owns the 
rights to 75%, or 15.0 Bcf, of the designed gas storage 
capacity at the facility.

The California gas storage market is challenged by low 
market prices and low market price volatility resulting from 
the abundant supply of natural gas to, and natural gas 
storage in, the region. We have substantially completed 
contracting for this facility for the 2018-19 gas year at pricing 
that was lower than expected and low relative to the pricing 
in our original long-term contracts which ended primarily in 
the 2013-14 gas storage year. 

We have believed and continue to believe that we may see 
storage price improvements or an increase in the demand 
for natural gas in the future driven by a number of factors, 
including changes in electric generation triggered by 
California's renewable portfolio standards, an increase in 
use of alternative fuels to meet carbon emission reduction 
targets, growth of the California economy, growth of 
domestic industrial manufacturing, potential exports of 
liquefied natural gas from the west coast, and other 
favorable storage market conditions in and around 
California. These factors, if they were to occur, may 
contribute to higher summer/winter natural gas price 
spreads, gas price volatility, and gas storage values, but 
there can be no assurance that any of the foregoing will 
occur. To the contrary, we have not seen the rebound in 
storage pricing as we originally anticipated. 

 
For the last few years, we have been diligently pursuing 
opportunities to increase revenues at the Gill Ranch Facility. 
Simultaneously, we have been conducting a strategic review 
of Gill Ranch and exploring all strategic alternatives. 
In the fourth quarter of 2017, we completed our 
comprehensive strategic review process, which included a 
sale process for our portion of the Gill Ranch Facility, and 
made a determination that Gill Ranch is no longer 
considered core to our long-term growth plans. 

We will continue to pursue all strategic options for this asset, 
including, but not limited to, a potential sale. In the 
meantime, we remain committed to operating the facility to 
the highest safety standards. See Note 2 and Part II, Item 7 
"Application of Critical Accounting Policies and Estimates". 

SERVICES. Gill Ranch provides intrastate, multi-cycle 
storage services in California at market-based rates under a 
CPUC-approved tariff that includes firm storage service, 
interruptible storage service, and park and loan storage 
services. The Gill Ranch Facility is not currently authorized 
to provide interstate gas storage services.

CUSTOMERS. Customer contracts for firm storage capacity 
at Gill Ranch have contract terms for as long as 27 years in 
duration; however, the majority of the contracted capacity is 
shorter term in nature due to market conditions. In the near-
term, we expect Gill Ranch to contract for terms ranging 
from one to five years. For the 2017-18 gas storage year, 
Gill Ranch has several storage customers, with the largest 
single contract accounting for approximately 13% of our 
storage capacity. In the near-term, we continue to expect 
shorter contract lengths reflecting current market prices and 
trends. 

The California market served by Gill Ranch is larger, and 
has a greater diversity of prospective customers, than the 
Pacific Northwest market served by Mist. Therefore, we 
expect less sensitivity to any single customer or group of 
customers at Gill Ranch. Current Gill Ranch customers 
provide energy related services, including natural gas 
production, marketing, and electric generation.

COMPETITIVE CONDITIONS. The Gill Ranch Facility currently 
competes with a number of other storage providers, 
including local integrated gas companies and other 
independent storage providers (ISPs) in the northern 
California market. There are currently four ISPs authorized 
by the CPUC to provide storage services in California, with 
the Gill Ranch Facility comprising approximately 12% of the 
storage capacity held by ISPs. An acquisition during 2016 
consolidated approximately 80% of the storage capacity 
authorized by the CPUC to ISPs in California. 

In late 2015, a significant natural gas leak occurred at an 
unaffiliated southern California gas storage facility. In 
response to the incident, both state and federal additional 
regulations were developed. The California Department of 
Oil, Gas and Geothermal Resources (DOGGR) developed 
and proposed new regulations for gas storage wells that 
focus on implementing additional well integrity requirements. 
Initial draft regulations suggested that individual well risk 
would be the basis for testing and implementation of 
subsurface modifications for all wells. This would potentially 
allow for a multiple year timeframe to comply after the 

10

issuance of the regulations with any necessary capital 
expenditures completed over several years after completing 
the testing period. DOGGR released a new formulation of 
these rules on February 12, 2018. Although these rules are 
subject to a comment period and possible revision, these 
rules establish a timeframe for completion of compliance 
within seven years, a period much shorter than we originally 
anticipated. We anticipate the final version of these 
regulations will be finalized in 2018. In addition, PHMSA 
proposed new federal regulations for underground natural 
gas storage facilities that focus on implementing additional 
pipeline safety requirements of downhole facilities, including 
operations, maintenance, and emergency response 
activities regarding wells, wellbore tubing, and casing. 

While the regulations are still under development, and their 
ultimate impact is unknown, it is likely the final PHMSA and 
DOGGR regulations will result in higher costs for all storage 
providers. As a result of the legislation and proposed 
regulation, the nature of, and demand for, future storage 
contracts, costs of operating, and market values in 
California could be impacted and remain uncertain at this 
time. 

SEASONALITY. While the majority of our Gill Ranch 
revenues are not subject to seasonality, and although we 
expect much of the storage revenue at Gill Ranch to be in 
the form of fixed monthly demand charges, cash flows can 
fluctuate due to timing of asset management and other 
revenues. In addition, a significant portion of operating costs 
at Gill Ranch are subject to fluctuations based on periods 
when storage customers elect to inject or withdraw.

REGULATION. Gill Ranch has a tariff on file with the CPUC 
authorizing it to charge market-based rates for the storage 
services offered. For additional discussion, see Part II, Item 
7, "Results of Operations–Regulatory Matters".

EXPANSION OPPORTUNITIES. Subject to market demand, 
project execution, available financing, receipt of future 
permits, and other rights, the Gill Ranch Facility can be 
expanded beyond the current combined ownership 
designed storage capacity of 20 Bcf without further 
expansion of the takeaway pipeline system. Taking these 
considerations into account and with certain infrastructure 
modifications, we currently estimate the Gill Ranch Facility 
could support an additional 25 Bcf of storage capacity, 
bringing the total storage capacity to approximately 45 Bcf, 
of which our current rights would give us up to an additional 
7.5 Bcf or ownership of a total of approximately 22.5 Bcf. 
We have no plans to expand the facility.

Asset Management
We contract with an independent energy marketing 
company to provide asset management services, primarily 
through the use of commodity exchange agreements and 
pipeline capacity release transactions. The results are 
included in the gas storage segment, except for amounts 
allocated to our utility pursuant to regulatory sharing 
agreements involving the use of utility assets. Utility pre-tax 
income from third-party asset management services is 
subject to revenue sharing with core utility customers. For 
additional discussion, see Part II, Item 7, "Results of 
Operations—Business Segments—Gas Storage".

OTHER 

We have non-utility investments and other business 
activities which are aggregated and reported as other. Other 
primarily consists of: 
• 
• 

non-utility appliance retail center operations; 
an equity method investment in TWH, a joint venture to 
build and operate a gas transmission pipeline in 
Oregon. TWH is owned 50% by NWN Energy, a wholly-
owned subsidiary of NW Natural, and 50% by 
TransCanada American Investments Ltd., an indirect 
wholly-owned subsidiary of TransCanada Corporation;
a minority interest in the Kelso-Beaver Pipeline held by 
our wholly-owned subsidiary NNG Financial 
Corporation (NNG Financial); and 
other operating and non-operating income and 
expenses of the parent company that are not included 
in utility or gas storage operations. 

• 

• 

The pipelines referred to above are regulated by FERC. 
Less than 1% of our consolidated assets and consolidated 
net loss are related to activities in other. For summary 
information for these assets and results of operations, see 
Note 4.

We have signed agreements to purchase two privately-
owned water utilities in the Pacific Northwest. If completed, 
we do not expect these transactions or their continued 
operations to have a material impact on our financial 
position. We expect to include financial results from these 
businesses in other. 

ENVIRONMENTAL MATTERS 

Properties and Facilities  
We own, or previously owned, properties and facilities that 
are currently being investigated that may require 
environmental remediation and are subject to federal, state, 
and local laws and regulations related to environmental 
matters. These laws and regulations may require 
expenditures over a long time frame to address certain 
environmental impacts. Estimates of liabilities for 
environmental costs are difficult to determine with precision 
because of the various factors that can affect their ultimate 
disposition. These factors include, but are not limited to, the 
following:
• 
• 

the complexity of the site;
changes in environmental laws and regulations at the 
federal, state, and local levels;
the number of regulatory agencies or other parties 
involved;
new technology that renders previous technology 
obsolete, or experience with existing technology that 
proves ineffective;
the ultimate selection of a particular technology;
the level of remediation required;
variations between the estimated and actual period of 
time that must be dedicated to respond to an 
environmentally-contaminated site; and 
the application of environmental laws that impose joint 
and several liabilities on all potentially responsible 
parties. 

• 

• 

• 
• 
• 

• 

We have received recovery of a portion of such 
environmental costs through insurance proceeds and seek 
the remainder of such costs through customer rates, and we 
believe recovery of these costs is probable. In Oregon, we 
have a mechanism to recover expenses, subject to an 
earnings test and allocation rules. See Part II, Item 7, 
"Results of Operations—Rate Matters—Rate Mechanisms—
Environmental Costs", Note 2, and Note 15.

Greenhouse Gas Matters
We recognize our businesses are likely to be impacted by 
future requirements to address greenhouse gas emissions. 
Future federal and/or state requirements may seek to limit 
emissions of greenhouse gases, including both carbon 
dioxide (CO2) and methane. These potential laws and 
regulations may require certain activities to reduce 
emissions and/or increase the price paid for energy based 
on its carbon content. 

Current federal rules require the reporting of greenhouse 
gas emissions. In September 2009, the Environmental 
Protection Agency (EPA) issued a final rule requiring the 
annual reporting of greenhouse gas emissions from certain 
industries, specified large greenhouse gas emission 
sources, and facilities that emit 25,000 metric tons or more 
of CO2 equivalents per year. We began reporting emission 
information in 2011. Under this reporting rule, local gas 
distribution companies like NW Natural are required to 
report system throughput to the EPA on an annual basis. 
The EPA also issued additional greenhouse gas reporting 
regulations requiring the annual reporting of fugitive 
emissions from our operations. 

In addition, the state of Washington's DOE enacted the 
Clean Air Rule (CAR) in 2016, which capped the maximum 
greenhouse gas emissions allowed from stationary sources, 
such as natural gas utilities. For gas distribution utilities, the 
production of emissions from usage by their customers was 
considered to be production of emissions attributable to the 
utility. In December 2017, in a Washington State Court 
proceeding, the Judge ruled that the Department of Ecology 
lacked legislative authority to regulate non-emitting sources, 
such as local distribution companies. The DOE has not yet 
indicated whether it will appeal the ruling. Currently, the 
Washington state legislature is considering other similar 
legislation. 

Additionally, the Oregon legislature is currently considering 
various greenhouse gas reduction proposals, including cap 
and trade. One such bill would create a declining cap, 
beginning 2021, on greenhouse gas emissions emitted by a 
wide variety of emission sources, including electric and 
natural gas utilities, and would require large utilities to hold 
permits, or allowances, to emit greenhouse gas emissions 
on a per ton basis. The Oregon legislature is currently 
reviewing these proposals, and we expect them to review 
similar proposals in the future. While there is uncertainty 
regarding potential compliance costs and revenue sharing 
impacts of these and other similar proposals, we currently 
expect to be able to recover compliance costs in rates, and 
as such, do not expect this legislation to materially affect our 
consolidated financial position and results of operations.

The outcome of these or any additional federal and state 
policy developments in the area of climate change cannot 

11

be determined at this time, but these initiatives could 
produce a number of results including new regulations, legal 
actions, additional charges to fund energy efficiency 
activities, or other regulatory actions. The adoption and 
implementation of any regulations limiting emissions of 
greenhouse gases from our operations could require us to 
incur costs to reduce emissions of greenhouse gases 
associated with our operations, which could result in an 
increase in the prices we charge our customers or a decline 
in the demand for natural gas. On the other hand, because 
natural gas is a low-carbon fuel, it is also possible future 
carbon constraints could create additional demand for 
natural gas for electric generation, direct use of natural gas 
in homes and businesses, and as a reliable and relatively 
low-emission back-up fuel source for alternative energy 
sources. Requirements to reduce greenhouse gas 
emissions from the transportation sector, such as those in 
Oregon’s clean fuel standard, could also result in additional 
demand for natural gas fueled vehicles. 

We continue to take proactive steps to collaboratively 
address future greenhouse gas emission matters, including 
actively participating in policy development in Oregon and, 
at the federal level, within the American Gas Association. 
We engage in policy development to help drive policies that 
result in real and meaningful greenhouse gas emission 
reductions that are affordable for our customers, and identify 
ways to reduce greenhouse gas emissions in our own 
operations. We have developed a voluntary carbon savings 
initiative consisting of activities that fall into three broad 
categories: (1) reducing the carbon intensity of our product, 
(2) helping customers use less energy, and (3) displacing 
higher carbon fuels, such as replacing diesel in heavy duty 
vehicles. Additionally, we help our customers reduce and 
offset their gas use through partnership with the Energy 
Trust of Oregon offering efficiency programs and the Smart 
Energy program, which allows customers to voluntarily 
contribute funds to projects such as biodigesters on dairy 
farms that offset the greenhouse gases produced from their 
natural gas use.

EMPLOYEES 

At December 31, 2017, our utility workforce consisted of 
1,146 employees, of which 629 were members of the Office 
and Professional Employees International Union (OPEIU) 
Local No. 11, AFL-CIO, and 517 were non-union employees. 
Our labor agreement with members of OPEIU covers 
wages, benefits, and working conditions. On May 22, 2014, 
our union employees ratified a new labor agreement (Joint 
Accord) that extends to November 30, 2019, and thereafter 
from year to year unless either party serves notice of its 
intent to negotiate modifications to the collective bargaining 
agreement. 

At December 31, 2017, our non-utility subsidiaries had a 
combined workforce of 14 non-union employees, of which 
eight had unionized as part of IBEW Local Union No. 1245 
(IBEW) and were in the process of negotiating a collective 
bargaining agreement. In January 2018, we were notified by 
the majority of those represented employees that they no 
longer wished to be represented by IBEW as their 
bargaining agent. Therefore, our gas storage segment is no 
longer recognizing IBEW as the bargaining agent for these 
eight employees.

12

Our subsidiaries receive certain services from centralized 
operations at the utility, and the utility is reimbursed for 
those services pursuant to a Shared Services Agreement.

ADDITIONS TO INFRASTRUCTURE

We make capital expenditures in order to maintain and 
enhance the safety and integrity of our pipelines, gate 
stations, storage facilities, and related assets, to expand the 
reach or capacity of those assets, or improve the efficiency 
of our operations. We expect to make a significant level of 
capital expenditures for additions to utility and gas storage 
infrastructure over the next five years, reflecting continued 
investments in customer growth, distribution system 
improvements, technology, and an expansion at our North 
Mist gas storage facility. 

For the five-year period from 2018 to 2022, capital 
expenditures are estimated to be between $750 and $850 
million.

Included in the five year period, 2018 utility capital 
expenditures are estimated to be between $190 and $220 
million, including $20 to $30 million to complete the 
construction of our North Mist gas storage facility expansion. 
We expect to invest less than $5 million in non-utility capital 
investments for gas storage and other activities in 2018. 
Additional investments in our infrastructure during and after 
2018 will depend largely on additional regulations and 
expansion opportunities. See additional discussion in Part II, 
Item 7 "Financial Condition—Cash Flows—Investing 
Activities". 

EXECUTIVE OFFICERS OF THE REGISTRANT

For information concerning our executive officers, see Part 
III, Item 10.

AVAILABLE INFORMATION

We file annual, quarterly and current reports and other 
information with the Securities and Exchange Commission 
(SEC). Reports, proxy statements, and other information 
filed by us can be read, copied, and requested through the 
SEC by mail at U.S. Securities and Exchange Commission, 
100 F Street, N.E., Washington, D.C. 20549, or online at its 
website (http://www.sec.gov). You can obtain information 
about access to the Public Reference Room and how to 
access or request records by calling the SEC at 1-800-
SEC-0330. The SEC website contains reports, proxy and 
information statements, and other information we file 
electronically. In addition, we make available on our website 
(http://www.nwnatural.com), our annual report on Form 10-
K, quarterly reports on Form 10-Q, current reports on Form 
8-K, and amendments to those reports filed or furnished 
pursuant to Section 13(a) or 15(d) and proxy materials filed 
under Section 14 of the Securities Exchange Act of 1934, as 
amended (Exchange Act), as soon as reasonably 
practicable after we electronically file such material with, or 
furnish it to, the SEC. We have included our website 
address as an inactive textual reference only. Information 
contained on our website is not incorporated by reference 
into this annual report on Form 10-K.

We have adopted a Code of Ethics for all employees, 
officers, and directors that is available on our website. We 
intend to disclose revisions and amendments to, and any 
waivers from, the Code of Ethics for officers and directors 
on our website. Our Corporate Governance Standards, 
Director Independence Standards, charters of each of the 
committees of the Board of Directors, and additional 
information about the Company are also available at the 
website. Copies of these documents may be requested, at 
no cost, by writing or calling Shareholder Services, NW 
Natural, One Pacific Square, 220 N.W. Second Avenue, 
Portland, Oregon 97209, telephone 503-226-4211 ext. 2402.

13

ITEM 1A. RISK FACTORS 

Our business and financial results are subject to a number 
of risks and uncertainties, many of which are not within our 
control, which could adversely affect our business, financial 
condition, and results of operations. Additional risks and 
uncertainties that are not currently known to the Company 
or that are not currently believed by the Company to be 
material may also harm the Company's business, financial 
condition, and results of operations. When considering any 
investment in our securities, investors should carefully 
consider the following information, as well as information 
contained in the caption "Forward-Looking Statements", 
Item 7A, and other documents we file with the SEC. This list 
is not exhaustive and the order of presentation does not 
reflect management’s determination of priority or likelihood. 
Additionally, our listing of risk factors that primarily affects 
one of our business segments does not mean that such risk 
factor is inapplicable to our other business segments.

Risks Related to our Business Generally
REGULATORY RISK. Regulation of our businesses, including 
changes in the regulatory environment, failure of regulatory 
authorities to approve rates which provide for timely 
recovery of our costs and an adequate return on invested 
capital, or an unfavorable outcome in regulatory 
proceedings may adversely impact our financial condition 
and results of operations.

The OPUC and WUTC have general regulatory authority 
over our utility business in Oregon and Washington, 
respectively, including the rates charged to customers, 
authorized rates of return on rate base, including ROE, the 
amounts and types of securities we may issue, services we 
provide and the manner in which we provide them, the 
nature of investments we make, actions investors may take 
with respect to our company, and deferral and recovery of 
various expenses, including, but not limited to, pipeline 
replacement, environmental remediation costs, commodity 
hedging expense, transactions with affiliated interests, 
weather adjustment mechanisms and other matters. 
Similarly, in our gas storage businesses FERC has 
regulatory authority over interstate storage services, the 
CPUC has regulatory authority over our Gill Ranch storage 
operations, and the WUTC and OPUC have regulatory 
authority over our Mist storage operations. Additionally, 
expansion of our business, including into water or other 
sectors, could result in regulation by other regulatory 
authorities. 

The prices the OPUC and WUTC allow us to charge for 
retail service, and the maximum FERC-approved rates 
FERC authorizes us to charge for interstate storage and 
related transportation services, are the most significant 
factors affecting our financial position, results of operations 
and liquidity. The OPUC and WUTC have the authority to 
disallow recovery of costs they find imprudently incurred or 
otherwise disallowed. Additionally, the rates allowed by the 
FERC may be insufficient for recovery of costs incurred. We 
expect to continue to make expenditures to expand, improve 
and operate our utility distribution and gas storage systems. 
Regulators can find such expansions or improvements of 
expenditures were not prudently incurred, and deny 
recovery. Additionally, while the OPUC and WUTC have 

14

established an authorized rate of return for our utility 
through the ratemaking process, the regulatory process 
does not provide assurance that we will be able to achieve 
the earnings level authorized. Moreover, in the normal 
course of business we may place assets in service or incur 
higher than expected levels of operating expense before 
rate cases can be filed to recover those costs—this is 
commonly referred to as regulatory lag. The failure of any 
regulatory commission to approve requested rate increases 
on a timely basis to recover increased costs or to allow an 
adequate return could adversely impact our financial 
condition and results of operations.

As a regulated utility, we frequently have dockets open with 
our regulators. The regulatory proceedings for these 
dockets typically involve multiple parties, including 
governmental agencies, consumer advocacy groups, and 
other third parties. Each party has differing concerns, but all 
generally have the common objective of limiting amounts 
included in rates. We cannot predict the timing or outcome 
of these deferred proceedings or the effects of those 
outcomes on our results of operations and financial 
condition.

ENVIRONMENTAL LIABILITY RISK. Certain of our properties 
and facilities may pose environmental risks requiring 
remediation, the costs of which are difficult to estimate and 
which could adversely affect our financial condition, results 
of operations, and cash flows.

We own, or previously owned, properties that require 
environmental remediation or other action. We accrue all 
material loss contingencies relating to these properties. A 
regulatory asset at the utility has been recorded for 
estimated costs pursuant to a Deferral Order from the 
OPUC and WUTC. In addition to maintaining regulatory 
deferrals, we settled with most of our historical liability 
insurers for only a portion of the costs we have incurred to 
date and expect to incur in the future. To the extent amounts 
we recovered from insurance are inadequate or we are 
unable to recover these deferred costs in utility customer 
rates, we would be required to reduce our regulatory assets 
which would result in a charge to current year earnings. In 
addition, in Oregon, the OPUC approved the SRRM, which 
limits recovery of our deferred amounts to those amounts 
which satisfy an annual prudence review and earnings test 
that requires the Company to contribute additional amounts 
toward environmental remediation costs above 
approximately $10 million in years in which the Company 
earns above its authorized Return on Equity (ROE). To the 
extent the Company earns more than its authorized ROE in 
a year, the Company would be required to cover 
environmental expenses greater than the $10 million with 
those earnings that exceed its authorized ROE. In addition, 
the OPUC ordered a review of the SRRM in 2018 or when 
we obtain greater certainty of environmental costs, 
whichever occurs first. These ongoing prudence reviews, 
the earnings test, or the three-year review could reduce the 
amounts we are allowed to recover, and could adversely 
affect our financial condition, results of operations and cash 
flows.

Moreover, we may have disputes with regulators and other 
parties as to the severity of particular environmental 
matters, what remediation efforts are appropriate, and the 

portion of the costs we should bear. We cannot predict with 
certainty the amount or timing of future expenditures related 
to environmental investigation, remediation or other action, 
the portions of these costs allocable to us, or disputes or 
litigation arising in relation thereto. 

Our liability estimates are based on current remediation 
technology, industry experience gained at similar sites, an 
assessment of our probable level of responsibility, and the 
financial condition of other potentially responsible parties. 
However, it is difficult to estimate such costs due to 
uncertainties surrounding the course of environmental 
remediation, the preliminary nature of certain of our site 
investigations, and the application of environmental laws 
that impose joint and several liabilities on all potentially 
responsible parties. These uncertainties and disputes 
arising therefrom could lead to further adversarial 
administrative proceedings or litigation, with associated 
costs and uncertain outcomes, all of which could adversely 
affect our financial condition, results of operations and cash 
flows. 

ENVIRONMENTAL REGULATION COMPLIANCE RISK. We are 
subject to environmental regulations for our ongoing 
operations, compliance with which could adversely affect 
our operations or financial results.

We are subject to laws, regulations and other legal 
requirements enacted or adopted by federal, state and local 
governmental authorities relating to protection of the 
environment, including those legal requirements that govern 
discharges of substances into the air and water, the 
management and disposal of hazardous substances and 
waste, groundwater quality and availability, plant and wildlife 
protection, and other aspects of environmental regulation. 
For example, we are subject to reporting requirements to 
the Environmental Protection Agency and the Oregon 
Department of Environmental Quality regarding greenhouse 
gas emissions. Similarly, there are current legislative efforts 
in Oregon and Washington to cap or otherwise restrict the 
maximum GHGs an entity may emit without reduction efforts 
or other undertakings. These and other current and future 
additional environmental regulations could result in 
increased compliance costs or additional operating 
restrictions, which may or may not be recoverable in 
customer rates or through insurance. If these costs are not 
recoverable, they could have an adverse effect on our 
financial condition and results of operations.

GLOBAL CLIMATE CHANGE RISK. Future legislation to 
address global climate change may expose us to regulatory 
and financial risk. Additionally, our business may be subject 
to physical risks associated with climate change, all of which 
could adversely affect our financial condition, results of 
operations and cash flows.

There are a number of international, federal and state 
legislative and regulatory initiatives being proposed and 
adopted in an attempt to measure, control or limit the effects 
of global warming and climate change, including 
greenhouse gas emissions such as carbon dioxide and 
methane. Such current or future legislation or regulation 
could impose on us operational requirements, additional 
charges to fund energy efficiency initiatives, or levy a tax 
based on carbon content. Such initiatives could result in us 

15

incurring additional costs to comply with the imposed 
restrictions, provide a cost advantage to energy sources 
other than natural gas, reduce demand for natural gas, 
impose costs or restrictions on end users of natural gas, 
impact the prices we charge our customers, impose 
increased costs on us associated with the adoption of new 
infrastructure and technology to respond to such 
requirements, and may impact cultural perception of our 
service or products negatively, diminishing the value of our 
brand, all of which could adversely affect our business 
practices, financial condition and results of operations.

Climate change may cause physical risks, including an 
increase in sea level, intensified storms, water scarcity and 
changes in weather conditions, such as changes in 
precipitation, average temperatures and extreme wind or 
other climate conditions. A significant portion of the nation’s 
gas infrastructure is located in areas susceptible to storm 
damage that could be aggravated by wetland and barrier 
island erosion, which could give rise to gas supply 
interruptions and price spikes.

These and other physical changes could result in 
disruptions to natural gas production and transportation 
systems potentially increasing the cost of gas and affecting 
our ability to procure gas to meet our customer demand. 
These changes could also affect our distribution systems 
resulting in increased maintenance and capital costs, 
disruption of service, regulatory actions and lower customer 
satisfaction. Additionally, to the extent that climate change 
adversely impacts the economic health or weather 
conditions of our service territory directly, it could adversely 
impact customer demand or our customers' ability to pay. 
Such physical risks could have an adverse effect on our 
financial condition, results of operations, and cash flows.

STRATEGIC TRANSACTION RISK. Our ability to successfully 
complete strategic transactions, including merger, 
acquisition, divestiture, joint venture, business development 
projects or other strategic transactions is subject to 
significant risks, including the risk that required regulatory or 
governmental approvals may not be obtained, risks relating 
to unknown or undisclosed problems or liabilities, and the 
risk that for these or other reasons, we may be unable to 
achieve some or all of the benefits that we anticipate from 
such transactions which could adversely affect our financial 
condition, results of operations, and cash flows.

From time to time, we have pursued and may continue to 
pursue strategic transactions including merger, acquisition, 
divestiture, joint venture, business development projects or 
other strategic transactions. Any such transactions involve 
substantial risks, including the following:

• 

• 

acquired businesses or assets may not produce 
revenues, earnings or cash flow at anticipated 
levels;
acquired businesses or assets could have, or 
supply, environmental, permitting, or other 
problems for which contractual protections prove 
inadequate;

•  we may experience difficulties in integration or 

operation costs of new businesses;

•  we may assume liabilities which were not disclosed 
to us, that exceed our estimates, or for which our 
rights to indemnification from the seller are limited;

 
•  we may be unable to obtain the necessary 

regulatory or governmental approvals to close a 
transaction, such approvals may be granted 
subject to terms that are unacceptable to us, or we 
may be unable to achieve anticipated regulatory 
treatment of any such transaction, or such benefits 
may be delayed or not occur at all;

•  we may agree to sell assets for a price that is less 

than the book value of those assets.

One of more of these conditions could affect our financial 
condition, results of operations, and cash flows.

BUSINESS DEVELOPMENT RISK. Our business development 
projects may encounter unanticipated obstacles, costs, 
changes or delays that could result in a project becoming 
impaired, which could negatively impact our financial 
condition, results of operations and cash flows.

Business development projects involve many risks. We are 
currently engaged in several business development 
projects, including, but not limited to, the early planning and 
development stages for a regional pipeline in Oregon, and 
an expansion of our gas storage facility at Mist. We may 
also engage in other business development projects such 
as investment in additional long-term gas reserves, CNG 
refueling stations, or projects in the water sector. These 
projects may not be successful.  Additionally, we may not be 
able to obtain required governmental permits and approvals 
to complete our projects in a cost-efficient or timely manner 
potentially resulting in delays or abandonment of the 
projects. We could also experience startup and construction 
delays, construction cost overruns, disputes with 
contractors, inability to negotiate acceptable agreements 
such as rights-of-way, easements, construction, gas supply 
or other material contracts, changes in customer demand or 
commitment, public opposition to projects, changes in 
market prices, and operating cost increases. Additionally, we 
may be unable to finance our business development 
projects at acceptable interest rates or within a scheduled 
time frame necessary for completing the project. One or 
more of these events could result in the project becoming 
impaired, and such impairment could have an adverse effect 
on our financial condition and results of operations.

JOINT PARTNER RISK. Investing in business development 
projects through partnerships, joint ventures or other 
business arrangements affects our ability to manage certain 
risks and could adversely impact our financial condition, 
results of operations and cash flows.

We use joint ventures and other business arrangements to 
manage and diversify the risks of certain utility and non-
utility development projects, including our Trail West 
pipeline, Gill Ranch storage and our gas reserves 
agreements. We may acquire or develop part-ownership 
interests in other projects in the future, including but not 
limited to, in the water sector. Under these arrangements, 
we may not be able to fully direct the management and 
policies of the business relationships, and other participants 
in those relationships may take action contrary to our 
interests including making operational decisions that could 
affect our costs and liabilities. In addition, other participants 
may withdraw from the project, divest important assets, 
become financially distressed or bankrupt, or have 

16

economic or other business interests or goals that are 
inconsistent with ours. 

For example, our gas reserves arrangements, which 
operate as a hedge backed by physical gas supplies, 
involve a number of risks. These risks include gas 
production that is significantly less than the expected 
volumes, or no gas volumes; operating costs that are higher 
than expected; changes in our consolidated tax position or 
tax laws that could affect our ability to take, or timing of, 
certain tax benefits that impact the financial outcome of this 
transaction; inherent risks of gas production, including 
disruption to operations or complete shut-in of the field; and 
a participant in one of these business arrangements acting 
contrary to our interests. In addition, while the cost of the 
original gas reserves venture is currently included in 
customer rates and additional wells under that arrangement 
are recovered at a specific cost, the occurrence of one or 
more of these risks, could affect our ability to recover this 
hedge in rates.  Further, any new gas reserves 
arrangements have not been approved for inclusion in rates, 
and our regulators may ultimately determine to not include 
all or a portion of future transactions in rates. The realization 
of any of these situations could adversely impact the project 
as well as our financial condition, results of operations and 
cash flows. 

OPERATING RISK. Transporting and storing natural gas 
involves numerous risks that may result in accidents and 
other operating risks and costs, some or all of which may 
not be fully covered by insurance, and which could 
adversely affect our financial condition, results of operations 
and cash flows.

Our operations are subject to all of the risks and hazards 
inherent in the businesses of local gas distribution and 
storage, including:
• 

earthquakes, floods, storms, landslides and other 
adverse weather conditions and hazards;
leaks or other losses of natural gas or other chemicals 
or compounds as a result of the malfunction of 
equipment or facilities;
damages from third parties, including construction, farm 
and utility equipment or other surface users;
operator errors;
negative performance by our storage reservoirs that 
could cause us to fail to meet expected or forecasted 
operational levels or contractual commitments to our 
customers;
problems maintaining, or the malfunction of, pipelines, 
wellbores and related equipment and facilities that form 
a part of the infrastructure that is critical to the operation 
of our gas distribution and storage facilities;
collapse of underground storage caverns;
operating costs that are substantially higher than 
expected;

• 

• 

• 
• 

• 

• 
• 

• 

•  migration of natural gas through faults in the rock or to 
some area of the reservoir where existing wells cannot 
drain the gas effectively resulting in loss of the gas;
blowouts (uncontrolled escapes of gas from a pipeline 
or well) or other accidents, fires and explosions; and
risks and hazards inherent in the drilling operations 
associated with the development of the gas storage 
facilities and/or wells.

• 

 
These risks could result in personal injury or loss of human 
life, damage to and destruction of property and equipment, 
pollution or other environmental damage, breaches of our 
contractual commitments, and may result in curtailment or 
suspension of our operations, which in turn could lead to 
significant costs and lost revenues. Further, because our 
pipeline, storage and distribution facilities are in or near 
populated areas, including residential areas, commercial 
business centers, and industrial sites, any loss of human life 
or adverse financial outcomes resulting from such events 
could be significant. Additionally, we may not be able to 
maintain the level or types of insurance we desire, and the 
insurance coverage we do obtain may contain large 
deductibles or fail to cover certain hazards or cover all 
potential losses. The occurrence of any operating risks not 
covered by insurance could adversely affect our financial 
condition, results of operations and cash flows.

BUSINESS CONTINUITY RISK. We may be adversely 
impacted by local or national disasters, pandemic illness, 
terrorist activities, including cyber-attacks or data breaches, 
and other extreme events to which we may not be able to 
promptly respond.

Local or national disasters, pandemic illness, terrorist 
activities, including cyber-attacks and data breaches, and 
other extreme events are a threat to our assets and 
operations. Companies in critical infrastructure industries 
may face a heightened risk due to exposure to acts of 
terrorism, including physical and security breaches of our 
information technology infrastructure in the form of cyber-
attacks.  These attacks could target or impact our 
technology or mechanical systems that operate our 
distribution, transmission or storage facilities and result in a 
disruption in our operations, damage to our system and 
inability to meet customer requirements. In addition, the 
threat of terrorist activities could lead to increased economic 
instability and volatility in the price of natural gas or other 
necessary commodities that could affect our operations. 
Threatened or actual national disasters or terrorist activities 
may also disrupt capital or bank markets and our ability to 
raise capital or obtain debt financing, or impact our suppliers 
or our customers directly. Local disaster or pandemic illness 
could result in part of our workforce being unable to operate 
or maintain our infrastructure or perform other tasks 
necessary to conduct our business. A slow or inadequate 
response to events may have an adverse impact on 
operations and earnings. We may not be able to maintain 
sufficient insurance to cover all risks associated with local 
and national disasters, pandemic illness, terrorist activities 
and other events.  Additionally, large scale natural disasters 
or terrorist attacks could destabilize the insurance industry 
making insurance we do have unavailable, which could 
increase the risk that an event could adversely affect our 
operations or financial results.

HOLDING COMPANY DIVIDEND RISK.  If we were to 
reorganize as a holding company, the holding company 
would depend on its operating subsidiaries to meet financial 
obligations and the ability of the holding company to pay 
dividends on its common stock would be dependent on the 
receipt of dividends and other payments from its 
subsidiaries. 

If we were to implement a holding company structure, NW 

17

Natural common stock would be converted or exchanged 
into shares of a holding company with the only significant 
assets being the stock of its operating subsidiaries, 
including NW Natural. NW Natural and its current 
subsidiaries, which would become NW Holding’s direct and 
indirect subsidiaries, are separate and distinct legal entities, 
managed by their own boards of directors, and, as is 
currently the case, would have no obligation to pay any 
amounts to their respective shareholders, whether through 
dividends, loans or other payments. The ability of these 
companies to pay dividends or make other distributions on 
their common stock is now, and would continue to be, 
subject to, among other things: their results of operations, 
net income, cash flows and financial condition, as well as 
the success of their business strategies and general 
economic and competitive conditions; the prior rights of 
holders of existing and future debt securities and any future 
preferred stock issued by those companies; and any 
applicable legal restrictions.

In addition, the ability of the holding company’s subsidiaries 
to pay upstream dividends and make other distributions 
would be subject to applicable state law and regulatory 
restrictions. Under the OPUC and WUTC regulatory 
approvals for the holding company formation, if NW Natural 
ceases to comply with credit and capital structure 
requirements approved by the OPUC and WUTC, it will not, 
with limited exceptions, be permitted to pay dividends to the 
holding company. Under the OPUC and WUTC orders 
authorizing the Company to form a holding company, NW 
Natural may not pay dividends or make distributions to the 
holding company if NW Natural’s credit ratings and common 
equity levels fall below specified ratings and levels. If NW 
Natural’s long-term secured credit ratings are below A- for 
S&P and A3 for Moody’s, dividends may be issued so long 
as NW Natural’s common equity is 45% or above. If NW 
Natural’s long-term secured credit ratings are below BBB for 
S&P and Baa2 for Moody’s, dividends may be issued so 
long as NW Natural’s common equity is 46% or above. 
Dividends may not be issued if NW Natural’s long-term 
secured credit ratings fall to BB+ or below for S&P or Ba1 or 
below for Moody’s, or if NW Natural’s common equity is 
below 44%. In each case, with the common equity level to 
be determined on a preceding or projected 13-month basis.

HOLDING COMPANY PRIORITY RISK.  If a holding company 
structure is completed, the holding company’s ability to pay 
dividends on its common stock would be subject to the prior 
rights of holders of its indebtedness and preferred stock, if 
any. 

If we were to form a holding company, it may from time to 
time issue debt securities and preferred stock, as well as 
additional shares of holding company common stock, in 
order to make capital contributions to one or more of its 
subsidiaries or for other reasons, although NW Natural 
would likely continue to issue its own debt securities and 
may issue preferred stock. The holding company could also 
guarantee indebtedness of non-utility subsidiaries. The 
issuance or guaranty of securities by the holding company 
would not be subject to the prior approval of the state utility 
commissions. The consolidated enterprise could thus be 
more highly leveraged than NW Natural and its current 
subsidiaries. The holding company’s ability to pay dividends 
on its common stock would be subject to the prior rights of 

holders of the holding company’s debt securities (including 
guarantees) and preferred stock, if any.

In addition, the right of the holding company, as a 
shareholder, to receive assets of any of its direct or indirect 
subsidiaries upon the subsidiary’s liquidation or 
reorganization would be subject to the prior rights of the 
holders of existing and future debt securities and preferred 
stock issued by such subsidiaries, and, as in the case of 
dividends, the rights of holders of the holding company 
common stock to receive any such assets would be subject 
to the prior rights of the holders of the holding company’s 
debt securities (including guarantees) and preferred stock.

HOLDING COMPANY DIVERSIFICATION RISK.  The holding 
company may invest in unregulated activities that may prove 
to be riskier than the current activities of NW Natural, which 
could result in losses and adversely affect the holding 
company’s financial condition, results of operations and 
cash flows. 

The holding company structure may allow us greater 
opportunities to invest in regulated and unregulated 
businesses. These investments may involve greater risk 
than an investment in NW Natural. If losses are incurred in 
unregulated businesses, they will likely not be recoverable 
through utility rates and they could adversely affect the 
holding company’s financial condition, results of operations 
and cash flows. 

EMPLOYEE BENEFIT RISK. The cost of providing pension 
and postretirement healthcare benefits is subject to changes 
in pension assets and liabilities, changing employee 
demographics and changing actuarial assumptions, which 
may have an adverse effect on our financial condition, 
results of operations and cash flows.

Until we closed the pension plans to new hires, which for 
non-union employees was in 2006 and for union employees 
was in 2009, we provided pension plans and postretirement 
healthcare benefits to eligible full-time utility employees and 
retirees. Most of our current utility employees were hired 
prior to these dates, and therefore remain eligible for these 
plans. Our cost of providing such benefits is subject to 
changes in the market value of our pension assets, changes 
in employee demographics including longer life 
expectancies, increases in healthcare costs, current and 
future legislative changes, and various actuarial calculations 
and assumptions. The actuarial assumptions used to 
calculate our future pension and postretirement healthcare 
expense may differ materially from actual results due to 
significant market fluctuations and changing withdrawal 
rates, wage rates, interest rates and other factors. These 
differences may result in an adverse impact on the amount 
of pension contributions, pension expense or other 
postretirement benefit costs recorded in future periods. 
Sustained declines in equity markets and reductions in bond 
rates may have a material adverse effect on the value of our 
pension fund assets and liabilities. In these circumstances, 
we may be required to recognize increased contributions 
and pension expense earlier than we had planned to the 
extent that the value of pension assets is less than the total 
anticipated liability under the plans, which could have a 
negative impact on our financial condition, results of 
operations and cash flows.

18

WORKFORCE RISK. Our business is heavily dependent on 
being able to attract and retain qualified employees and 
maintain a competitive cost structure with market-based 
salaries and employee benefits, and workforce disruptions 
could adversely affect our operations and results.

Our ability to implement our business strategy and serve our 
customers is dependent upon our continuing ability to attract 
and retain talented professionals and a technically skilled 
workforce, and being able to transfer the knowledge and 
expertise of our workforce to new employees as our largely 
older workforce retires. We expect that a significant portion 
of our workforce will retire within the current decade, which 
will require that we attract, train and retain skilled workers to 
prevent loss of institutional knowledge or skills gap.  Without 
an appropriately skilled workforce, our ability to provide 
quality service and meet our regulatory requirements will be 
challenged and this could negatively impact our earnings. 
Additionally, within our utility segment, a majority of our 
workers are represented by the OPEIU Local No.11 AFL-
CIO, and are covered by a collective bargaining agreement 
that extends to November 30, 2019. Disputes with the union 
representing our employees over terms and conditions of 
their agreement could result in instability in our labor 
relationship and work stoppages that could impact the timely 
delivery of gas and other services from our utility and 
storage facilities, which could strain relationships with 
customers and state regulators and cause a loss of 
revenues. Our collective bargaining agreements may also 
limit our flexibility in dealing with our workforce, and our 
ability to change work rules and practices and implement 
other efficiency-related improvements to successfully 
compete in today’s challenging marketplace, which may 
negatively affect our financial condition and results of 
operations.

LEGISLATIVE, COMPLIANCE AND TAXING AUTHORITY RISK. 
We are subject to governmental regulation, and compliance 
with local, state and federal requirements, including taxing 
requirements, and unforeseen changes in or interpretations 
of such requirements could affect our financial condition and 
results of operations.

We are subject to regulation by federal, state and local 
governmental authorities. We are required to comply with a 
variety of laws and regulations and to obtain authorizations, 
permits, approvals and certificates from governmental 
agencies in various aspects of our business. Significant 
changes in federal, state, or local governmental leadership 
can accelerate or amplify changes in existing laws or 
regulations, or the manner in which they are interpreted or 
enforced. For example, the U.S. Presidential Administration 
has made numerous leadership changes at federal 
administrative agencies since the 2016 U.S. Presidential 
election. Moreover, the U.S. Congress and the U.S. 
Presidential Administration may make substantial changes 
to fiscal, tax, regulation and other federal policies. The U.S. 
Presidential Administration has called for significant 
changes to U.S. fiscal policies, U.S. trade, healthcare, 
immigration, foreign, and government regulatory policy. To 
the extent the U.S. Congress or U.S. Presidential 
Administration implements changes to U.S. policy, those 
changes may impact, among other things, the U.S. and 
global economy, international trade and relations, 
unemployment, immigration, corporate taxes, healthcare, 

the U.S. regulatory environment, inflation and other areas. 
Although we cannot predict the impact, if any, of these 
changes to our business, they could adversely affect our 
financial condition and results of operations. Until we know 
what policy changes are made and how those changes 
impact our business and the business of our competitors 
over the long term, we will not know if, overall, we will 
benefit from them or be negatively affected by them.

Though we cannot predict the changes in laws, regulations, 
or enforcement that are likely as a result of these transitions, 
we expect there to be a number of significant changes. We 
cannot predict with certainty the impact of any future 
revisions or changes in interpretations of existing 
regulations or the adoption of new laws and regulations. 
Additionally, any failure to comply with existing or new laws 
and regulations could result in fines, penalties or injunctive 
measures that could affect operating assets. For example, 
under the Energy Policy Act of 2005, the FERC has civil 
authority under the Natural Gas Act to impose penalties for 
current violations of up to $1 million per day for each 
violation. In addition, as the regulatory environment for our 
industry increases in complexity, the risk of inadvertent 
noncompliance may also increase. Changes in regulations, 
the imposition of additional regulations, and the failure to 
comply with laws and regulations could negatively influence 
our operating environment and results of operations. 

Additionally, changes in federal, state or local tax laws and 
their related regulations, or differing interpretations or 
enforcement of applicable law by a federal, state or local 
taxing authority, could result in substantial cost to us and 
negatively affect our results of operations. Tax law and its 
related regulations and case law are inherently complex and 
dynamic. Disputes over interpretations of tax laws may be 
settled with the taxing authority in examination, upon appeal 
or through litigation. Our judgments may include reserves 
for potential adverse outcomes regarding tax positions that 
have been taken that may be subject to challenge by taxing 
authorities. Changes in laws, regulations or adverse 
judgments and the inherent difficulty in quantifying potential 
tax effects of business decisions may negatively affect our 
financial condition and results of operations.

In this regard, the Tax Cuts and Jobs Act of 2017 was 
approved by the U.S. Congress on December 20, 2017 and 
signed into law by the U.S. President on December 22, 
2017. This legislation makes significant changes to the U.S. 
Internal Revenue Code. Such changes include a reduction 
in the corporate tax rate from 35% to 21% and limitations on 
certain corporate deductions and credits, among other 
changes. Certain of these changes may negatively affect 
our financial condition and results of operations. 

We expect that the elimination of bonus depreciation may 
increase taxes in 2018 and 2019, which may have an 
adverse effect on cash flows during this period. In addition, 
there is uncertainty as to how our regulators will reflect the 
impact of the legislation in rates. The resulting ratemaking 
treatment may negatively affect our financial condition and 
results of operations.

SAFETY REGULATION RISK. We may experience increased 
federal, state and local regulation of the safety of our 

systems and operations, which could adversely affect our 
operating costs and financial results.

The safety and protection of the public, our customers and 
our employees is and will remain our top priority. We are 
committed to consistently monitoring and maintaining our 
distribution system and storage operations to ensure that 
natural gas is acquired, stored and delivered safely, reliably 
and efficiently. Given recent high-profile natural gas 
explosions, leaks and accidents in other parts of the country 
involving both distribution systems and storage facilities, we 
anticipate that the natural gas industry may be the subject of 
even greater federal, state and local regulatory oversight. 
For example, in 2016, the Protecting our Infrastructure of 
Pipelines and Enhancing Safety Act (PIPES Act) was signed 
into law increasing regulations for natural gas storage 
pipelines and underground storage facilities. Similarly, in 
2016, California passed legislation directing the Department 
of Oil, Gas and Geothermal Resources (DOGGR) to 
develop regulations affecting gas storage operations. 
DOGGR has issued proposed regulations which we expect 
to go into effect within the first half of 2018. As currently 
written, these regulations require mechanical integrity 
testing and implementation of gas flow limited to tubing only 
for all wells at Gill Ranch within the next 7 years.

We intend to work diligently with industry associations and 
federal and state regulators to seek to ensure compliance 
with these and other new laws. We expect there to be 
increased costs associated with compliance, and those 
costs could be significant. If these costs are not recoverable 
in our customer rates, they could have a negative impact on 
our operating costs and financial results.

HEDGING RISK. Our risk management policies and hedging 
activities cannot eliminate the risk of commodity price 
movements and other financial market risks, and our 
hedging activities may expose us to additional liabilities for 
which rate recovery may be disallowed, which could result in 
an adverse impact on our operating revenues, costs, 
derivative assets and liabilities and operating cash flows.

Our gas purchasing requirements expose us to risks of 
commodity price movements, while our use of debt and 
equity financing exposes us to interest rate, liquidity and 
other financial market risks. In our Utility segment, we 
attempt to manage these exposures with both financial and 
physical hedging mechanisms, including our gas reserves 
transactions which are hedges backed by physical gas 
supplies. While we have risk management procedures for 
hedging in place, they may not always work as planned and 
cannot entirely eliminate the risks associated with hedging. 
Additionally, our hedging activities may cause us to incur 
additional expenses to obtain the hedge. We do not hedge 
our entire interest rate or commodity cost exposure, and the 
unhedged exposure will vary over time. Gains or losses 
experienced through hedging activities, including carrying 
costs, generally flow through the PGA mechanism or are 
recovered in future general rate cases. However, the hedge 
transactions we enter into for the utility are subject to a 
prudence review by the OPUC and WUTC, and, if found 
imprudent, those expenses may be, and have been 
previously, disallowed, which could have an adverse effect 
on our financial condition and results of operations. 

19

 
In addition, our actual business requirements and available 
resources may vary from forecasts, which are used as the 
basis for our hedging decisions, and could cause our 
exposure to be more or less than we anticipated. Moreover, 
if our derivative instruments and hedging transactions do not 
qualify for regulatory deferral and we do not elect hedge 
accounting treatment under generally accepted accounting 
standards, our results of operations and financial condition 
could be adversely affected.

We also have credit-related exposure to derivative 
counterparties. Counterparties owing us money or physical 
natural gas commodities could breach their obligations. 
Should the counterparties to these arrangements fail to 
perform, we may be forced to enter into alternative 
arrangements to meet our normal business requirements. In 
that event, our financial results could be adversely affected. 
Additionally, under most of our hedging arrangements, any 
downgrade of our senior unsecured long-term debt credit 
rating could allow our counterparties to require us to post 
cash, a letter of credit or other form of collateral, which 
would expose us to additional costs and may trigger 
significant increases in borrowing from our credit facilities if 
the credit rating downgrade is below investment grade.  
Further, based on current interpretations, we are not 
considered a "swap dealer" or "major swap participant" in 
2017, so we are exempt from certain requirements under 
the Dodd-Frank Act.  If we are unable to claim this 
exemption, we could be subject to higher costs for our 
derivatives activities. 

INABILITY TO ACCESS CAPITAL MARKET RISK. Our inability 
to access capital, or significant increases in the cost of 
capital, could adversely affect our financial condition and 
results of operations.

Our ability to obtain adequate and cost effective short-term 
and long-term financing depends on maintaining investment 
grade credit ratings as well as the existence of liquid and 
stable financial markets. Our businesses rely on access to 
capital and bank markets, including commercial paper, bond 
and equity markets, to finance our operations, construction 
expenditures and other business requirements, and to 
refund maturing debt that cannot be funded entirely by 
internal cash flows. Disruptions in capital markets could 
adversely affect our ability to access short-term and long-
term financing. Our access to funds under committed credit 
facilities, which are currently provided by a number of 
banks, is dependent on the ability of the participating banks 
to meet their funding commitments. Those banks may not 
be able to meet their funding commitments if they 
experience shortages of capital and liquidity. Disruptions in 
the bank or capital financing markets as a result of 
economic uncertainty, changing or increased regulation of 
the financial sector, or failure of major financial institutions 
could adversely affect our access to capital and negatively 
impact our ability to run our business and make strategic 
investments.

A negative change in our current credit ratings, particularly 
below investment grade, could adversely affect our cost of 
borrowing and access to sources of liquidity and capital. 
Such a downgrade could further limit our access to 
borrowing under available credit lines. Additionally, 
downgrades in our current credit ratings below investment 

20

grade could cause additional delays in accessing the capital 
markets by the utility while we seek supplemental state 
regulatory approval, which could hamper our ability to 
access credit markets on a timely basis. A credit downgrade 
could also require additional support in the form of letters of 
credit, cash or other forms of collateral and otherwise 
adversely affect our financial condition and results of 
operations.

REPUTATIONAL RISKS. Customers', legislators', and 
regulators' opinions of us are affected by many factors, 
including system reliability and safety, protection of 
customer information, rates, media coverage, and public 
sentiment. To the extent that customers, legislators, or 
regulators have or develop a negative opinion of us, our 
financial positions, results of operations and cash flows 
could be adversely affected. 

A number of factors can affect customer satisfaction 
including: service interruptions or safety concerns due to 
failures of equipment or facilities or from other causes, and 
our ability to promptly respond to such failures; our ability to 
safeguard sensitive customer information; and the timing 
and magnitude of rate increases, and volatility of rates. 
Customers', legislators', and regulators' opinions of us can 
also be affected by media coverage, including the 
proliferation of social media, which may include information, 
whether factual or not, that damages our brand and 
reputation.

If customers, legislators, or regulators have or develop a 
negative opinion of us and our utility services, this could 
result in increased regulatory oversight and could affect the 
returns on common equity we are allowed to earn. 
Additionally, negative opinions about us could make it more 
difficult for us to achieve favorable legislative or regulatory 
outcomes. Negative opinions could also result in sales 
volumes reductions or increased use of other sources of 
energy. Any of these consequences could adversely affect 
our financial position, results of operations and cash flows. 

Risks Related Primarily to Our Local Utility Business
REGULATORY ACCOUNTING RISK. In the future, we may no 
longer meet the criteria for continued application of 
regulatory accounting practices for all or a portion of our 
regulated operations. 

If we could no longer apply regulatory accounting, we could 
be required to write off our regulatory assets and precluded 
from the future deferral of costs not recovered through rates 
at the time such amounts are incurred, even if we are 
expected to recover these amounts from customers in the 
future. 

GAS PRICE RISK. Higher natural gas commodity prices and 
volatility in the price of gas may adversely affect our results 
of operations and cash flows.

The cost of natural gas is affected by a variety of factors, 
including weather, changes in demand, the level of 
production and availability of natural gas supplies, 
transportation constraints, availability and cost of pipeline 
capacity, federal and state energy and environmental 
regulation and legislation, natural disasters and other 
catastrophic events, national and worldwide economic and 

political conditions, and the price and availability of 
alternative fuels. In our utility segment, the cost we pay for 
natural gas is generally passed through to our customers 
through an annual PGA rate adjustment. If gas prices were 
to increase significantly, it would raise the cost of energy to 
our utility customers, potentially causing those customers to 
conserve or switch to alternate sources of energy. 
Significant price increases could also cause new home 
builders and commercial developers to select alternative 
energy sources. Decreases in the volume of gas we sell 
could reduce our earnings, and a decline in customers could 
slow growth in our future earnings. Additionally, because a 
portion of any (10% or 20%) difference between the 
estimated average PGA gas cost in rates and the actual 
average gas cost incurred is recognized as current income 
or expense, higher average gas costs than those assumed 
in setting rates can adversely affect our operating cash 
flows, liquidity and results of operations. Additionally, 
notwithstanding our current rate structure, higher gas costs 
could result in increased pressure on the OPUC or the 
WUTC to seek other means to reduce rates, which also 
could adversely affect our results of operations and cash 
flows.

Higher gas prices may also cause us to experience an 
increase in short-term debt and temporarily reduce liquidity 
because we pay suppliers for gas when it is purchased, 
which can be in advance of when these costs are recovered 
through rates. Significant increases in the price of gas can 
also slow our collection efforts as customers experience 
increased difficulty in paying their higher energy bills, 
leading to higher than normal delinquent accounts 
receivable resulting in greater expense associated with 
collection efforts and increased bad debt expense.

CUSTOMER GROWTH RISK. Our utility margin, earnings and 
cash flow may be negatively affected if we are unable to 
sustain customer growth rates in our local gas distribution 
segment.

Our utility margins and earnings growth have largely 
depended upon the sustained growth of our residential and 
commercial customer base due, in part, to the new 
construction housing market, conversions of customers to 
natural gas from other energy sources and growing 
commercial use of natural gas. The last recession slowed 
new construction. While construction has resumed and the 
multi-family composition has been higher than its pre-
recession pace, overall construction has not returned to the 
pre-recession pace. Insufficient growth in these markets, for 
economic, political or other reasons could result in an 
adverse long-term impact on our utility margin, earnings and 
cash flows.

RISK OF COMPETITION. Our gas distribution business is 
subject to increased competition which could negatively 
affect our results of operations.

In the residential and commercial markets, our gas 
distribution business competes primarily with suppliers of 
electricity, fuel oil, and propane. In the industrial market, we 
compete with suppliers of all forms of energy. Competition 
among these forms of energy is based on price, efficiency, 
reliability, performance, market conditions, technology, 
environmental impacts and public perception.

21

Technological improvements in other energy sources such 
as heat pumps, batteries or other alternative technologies 
could erode our competitive advantage. If natural gas prices 
rise relative to other energy sources, or if the cost, 
environmental impact or public perception of such other 
energy sources improves relative to natural gas, it may 
negatively affect our ability to attract new customers or 
retain our existing residential, commercial and industrial 
customers, which could have a negative impact on our 
customer growth rate and results of operations.

RELIANCE ON THIRD PARTIES TO SUPPLY NATURAL GAS 
RISK. We rely on third parties to supply the natural gas in 
our distribution segment, and limitations on our ability to 
obtain supplies, or failure to receive expected supplies for 
which we have contracted, could have an adverse impact on 
our financial results.

Our ability to secure natural gas for current and future sales 
depends upon our ability to purchase and receive delivery of 
supplies of natural gas from third parties. We, and in some 
cases, our suppliers of natural gas do not have control over 
the availability of natural gas supplies, competition for those 
supplies, disruptions in those supplies, priority allocations on 
transmission pipelines, or pricing of those supplies. 
Additionally, third parties on whom we rely may fail to deliver 
gas for which we have contracted. If we are unable or are 
limited in our ability to obtain natural gas from our current 
suppliers or new sources, we may not be able to meet our 
customers' gas requirements and would likely incur costs 
associated with actions necessary to mitigate services 
disruptions, both of which could significantly and negatively 
impact our results of operations.

SINGLE TRANSPORTATION PIPELINE RISK. We rely on a 
single pipeline company for the transportation of gas to our 
service territory, a disruption of which could adversely 
impact our ability to meet our customers’ gas requirements.

Our distribution system is directly connected to a single 
interstate pipeline, which is owned and operated by 
Northwest Pipeline. The pipeline’s gas flows are bi-
directional, transporting gas into the Portland metropolitan 
market from two directions: (1) the north, which brings 
supplies from the British Columbia and Alberta supply 
basins; and (2) the east, which brings supplies from the 
Alberta and the U.S. Rocky Mountain supply basins. If there 
is a rupture or inadequate capacity in the pipeline, we may 
not be able to meet our customers’ gas requirements and 
we would likely incur costs associated with actions 
necessary to mitigate service disruptions, both of which 
could significantly and negatively impact our results of 
operations.

WEATHER RISK. Warmer than average weather may have a 
negative impact on our revenues and results of operations.

We are exposed to weather risk primarily in our utility 
segment. A majority of our volume is driven by gas sales to 
space heating residential and commercial customers during 
the winter heating season. Current utility rates are based on 
an assumption of average weather. Warmer than average 
weather typically results in lower gas sales. Colder weather 
typically results in higher gas sales. Although the effects of 
warmer or colder weather on utility margin in Oregon are 

expected to be mitigated through the operation of our 
weather normalization mechanism, weather variations from 
normal could adversely affect utility margin because we may 
be required to purchase more or less gas at spot rates, 
which may be higher or lower than the rates assumed in our 
PGA. Also, a portion of our Oregon residential and 
commercial customers (usually less than 10%) have opted 
out of the weather normalization mechanism, and 11% of 
our customers are located in Washington where we do not 
have a weather normalization mechanism. These effects 
could have an adverse effect on our financial condition, 
results of operations and cash flows.

CUSTOMER CONSERVATION RISK. Customers’ conservation 
efforts may have a negative impact on our revenues.

An increasing national focus on energy conservation, 
including improved building practices and appliance 
efficiencies may result in increased energy conservation by 
customers. This can decrease our sales of natural gas and 
adversely affect our results of operations because revenues 
are collected mostly through volumetric rates, based on the 
amount of gas sold. In Oregon, we have a conservation tariff 
which is designed to recover lost utility margin due to 
declines in residential and small commercial customers’ 
consumption. However, we do not have a conservation tariff 
in Washington that provides us this margin protection on 
sales to customers in that state.

RELIANCE ON TECHNOLOGY RISK. Our efforts to integrate, 
consolidate and streamline our operations have resulted in 
increased reliance on technology, the failure or security 
breach of which could adversely affect our financial 
condition and results of operations.

Over the last several years we have undertaken a variety of 
initiatives to integrate, standardize, centralize and 
streamline our operations. These efforts have resulted in 
greater reliance on technological tools such as: an 
enterprise resource planning system, an automated 
dispatch system, an automated meter reading system, a 
customer information system, a web-based ordering and 
tracking system, and other similar technological tools and 
initiatives. The failure of any of these or other similarly 
important technologies, or our inability to have these 
technologies supported, updated, expanded or integrated 
into other technologies, could adversely impact our 
operations. We take precautions to protect our systems, but 
there is no guarantee that the procedures we have 
implemented to protect against unauthorized access to 
secured data and systems are adequate to safeguard 
against all security breaches. Our utility could experience 
breaches of security pertaining to sensitive customer, 
employee, and vendor information maintained by the utility 
in the normal course of business, which could adversely 
affect the utility’s reputation, diminish customer confidence, 
disrupt operations, materially increase the costs we incur to 
protect against these risks, and subject us to possible 
financial liability or increased regulation or litigation, any of 
which could adversely affect our financial condition and 
results of operations.

Furthermore, we rely on information technology systems in 
our operations of our distribution and storage operations. 
There are various risks associated with these systems, 

22

including, hardware and software failure, communications 
failure, data distortion or destruction, unauthorized access to 
data, misuse of proprietary or confidential data, 
unauthorized control through electronic means, 
programming mistakes and other inadvertent errors or 
deliberate human acts. In particular, cyber security attacks, 
terrorism or other malicious acts could damage, destroy or 
disrupt all of our business systems. Any failure of 
information technology systems could result in a loss of 
operating revenues, an increase in operating expenses and 
costs to repair or replace damaged assets. As these 
potential cyber security attacks become more common and 
sophisticated, we could be required to incur costs to 
strengthen our systems or obtain specific insurance 
coverage against potential losses.

Risks Related Primarily to Our Gas Storage 
Businesses
LONG-TERM LOW OR STABILIZATION OF GAS PRICE RISK. 
Any significant stabilization of natural gas prices or long-
term low gas prices could have a negative impact on the 
demand for our natural gas storage services, which could 
adversely affect our financial results.

Storage businesses benefit from price volatility, which 
impacts the level of demand for services and the rates that 
can be charged for storage services. Largely due to the 
abundant supply of natural gas made available by hydraulic 
fracturing techniques, natural gas prices have dropped 
significantly to levels that are near historic lows. If prices 
and volatility remain low or decline further, then the demand 
for storage services, and the prices that we will be able to 
charge for those services, may decline or be depressed for 
a prolonged period of time. Prices below the costs to 
operate the storage facility could result in a decision to shut-
in all or a portion of the facility. A sustained decline in these 
prices or a shut-in of all or a portion of the facility could have 
an adverse impact on our financial condition, results of 
operations and cash flows.

NATURAL GAS STORAGE COMPETITION RISK. Increasing 
competition in the natural gas storage business could 
reduce the demand for our storage services and drive prices 
down for storage, which could adversely affect our financial 
condition, results of operations and cash flows.

Our natural gas storage segment competes primarily with 
other storage facilities and pipelines. Natural gas storage is 
an increasingly competitive business, with the ability to 
expand or build new storage capacity in California, the U.S. 
Rocky Mountains and elsewhere in the United States and 
Canada. Increased competition in the natural gas storage 
business could reduce the demand for our natural gas 
storage services, drive prices down for our storage 
business, and adversely affect our ability to renew or 
replace existing contracts at rates sufficient to maintain 
current revenues and cash flows, which could adversely 
affect our financial condition, results of operations and cash 
flows.

IMPAIRMENT OF LONG-LIVED ASSETS RISK. Additional 
impairments of the value of long-lived assets could have a 
material effect on our financial condition, or results of 
operations.

 
We review the carrying value of long-lived assets whenever 
events or changes in circumstances indicate the carrying 
amount of the assets might not be recoverable. The 
determination of recoverability is based on the undiscounted 
net cash flows expected to result from the operation of such 
assets. Projected cash flows depend on the future operating 
costs and projected revenues associated with the asset, 
storage pricing, the ability to contract with higher value 
customers, and the future market and price for gas storage 
over the remaining life of the asset. We recognized a $192.5 
million impairment of long-lived assets at the Gill Ranch 
Facility as of December 31, 2017. Further changes in 
revenues, operating costs, or a decision to sell the facility 
may result in an additional impairment of long-lived assets 
at the Gill Ranch Facility. Additionally, we review our other 
long-lived assets to determine if an impairment analysis is 
necessary. Any impairment charge taken with respect to our 
long-lived assets could be material and could have a 
material effect on our financial condition and results of 
operations.

THIRD-PARTY PIPELINE RISK. Our gas storage businesses 
depend on third-party pipelines that connect our storage 
facilities to interstate pipelines, the failure or unavailability of 
which could adversely affect our financial condition, results 
of operations and cash flows.

Our gas storage facilities are reliant on the continued 
operation of a third-party pipeline and other facilities that 
provide delivery options to and from our storage facilities. 
Because we do not own all of these pipelines, their 
operations are not within our control. If the third-party 
pipeline to which we are connected were to become 
unavailable for current or future withdrawals or injections of 
natural gas due to repairs, damage to the infrastructure, lack 
of capacity or other reasons, our ability to operate efficiently 
and satisfy our customers’ needs could be compromised, 
thereby potentially having an adverse impact on our 
financial condition, results of operations and cash flows.

ITEM 1B. UNRESOLVED STAFF COMMENTS

We have no unresolved comments.

23

 
ITEM 2. PROPERTIES

ITEM 3. LEGAL PROCEEDINGS 

Other than the proceedings disclosed in Note 15, we have 
only nonmaterial litigation in the ordinary course of 
business.

ITEM 4. MINE SAFETY DISCLOSURES

Not applicable.

Utility Properties
Our natural gas pipeline system consists of approximately 
20,000 miles of distribution and transmission mains located 
in our service territory in Oregon and Washington. In 
addition, the pipeline system includes service pipelines, 
meters and regulators, and gas regulating and metering 
stations. Pipeline mains are located in municipal streets or 
alleys pursuant to franchise or occupation ordinances, in 
county roads or state highways pursuant to agreements or 
permits granted pursuant to statute, or on lands of others 
pursuant to easements obtained from the owners of such 
lands. We also hold permits for the crossing of numerous 
navigable waterways and smaller tributaries throughout our 
entire service territory.

We own service building facilities in Portland, Oregon, as 
well as various satellite service centers, garages, 
warehouses, and other buildings necessary and useful in 
the conduct of our business. We also lease office space in 
Portland for our corporate headquarters, which expires on 
May 31, 2020. Resource centers are maintained on owned 
or leased premises at convenient points in the distribution 
system to provide service within our utility service territory. 
We also own LNG storage facilities in Portland and near 
Newport, Oregon.

In October 2017, we entered into a 20-year operating lease 
agreement for a new headquarters in Portland in 
anticipation of the expiration of our current lease in 2020. 
We executed an extensive search and evaluation process 
that focused on seismic preparedness, safety, reliability, the 
least cost to our customers, and a continued commitment to 
our employees and the communities we serve. Payments 
under the new lease are expected to commence in 2020.

Gas Storage Properties 
We hold leases and other property interests in 
approximately 12,000 net acres of underground natural gas 
storage in Oregon, approximately 5,000 net acres of 
underground natural gas storage in California, and 
easements and other property interests related to pipelines 
associated with those facilities. We own rights to depleted 
gas reservoirs near Mist, Oregon that are continuing to be 
developed and operated as underground gas storage 
facilities. We also hold all future storage rights in certain 
other areas of the Mist gas field in Oregon, as well as in 
California related to the Gill Ranch Facility.

We consider all of our properties currently used in our 
operations, both owned and leased, to be well maintained, 
in good operating condition, and, along with planned 
additions, adequate for our present and foreseeable future 
needs.

Our Mortgage and Deed of Trust (Mortgage) is a first 
mortgage lien on substantially all of the property constituting 
our utility plant.

24

  
 
 
  
PART II

ITEM 5. MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDER MATTERS AND 
ISSUER PURCHASES OF EQUITY SECURITIES

Our common stock is listed and trades on the New York Stock Exchange under the symbol NWN. The high and low trades for 
our common stock during the past two years were as follows:

Quarter Ended

March 31

June 30

September 30

December 31

2017

2016

High

Low

High

Low

$

61.70

$

56.53

$

54.51

$

63.40

68.60

69.50

57.65

59.15

58.55

64.84

66.17

61.85

The closing price for our common stock on the last trading day of 2017 and 2016 was $59.65 and $59.80, respectively. 

As of February 16, 2018, there were 5,213 holders of record of our common stock.

Dividends per share paid during the past two years were as follows:

Payment Month

February

May

August

November

Total per share

2017

2016

$

$

0.4700

$

0.4700

0.4700

0.4725

1.8825

$

48.90

49.46

57.96

53.50

0.4675

0.4675

0.4675

0.4700

1.8725

The declaration and amount of future dividends depend upon our earnings, cash flows, financial condition, and other factors. The 
amount and timing of dividends payable on our common stock are within the sole discretion of our Board of Directors. Subject to 
Board approval, we expect to continue paying cash dividends on our common stock on a quarterly basis. 

The following table provides information about purchases of our equity securities that are registered pursuant to Section 12 of 
the Securities Exchange Act of 1934 during the quarter ended December 31, 2017:

Period

Balance forward

10/01/17-10/31/17

11/01/17-11/30/17

12/01/17-12/31/17

Total

Issuer Purchases of Equity Securities

Total Number
of Shares Purchased(1)

Average
Price Paid per Share

Total Number of Shares
Purchased as Part of
Publicly Announced 
Plans or Programs(2)

Maximum Dollar Value of
Shares that May Yet Be
Purchased Under the 
Plans or Programs(2)

2,124,528

$

16,732,648

657

$

14,239

650

15,546

66.33

67.89

64.98

67.71

—

—

—

—

—

—

2,124,528

$

16,732,648

(1)  During the quarter ended December 31, 2017, the following number of shares of our common stock were purchased on the open market: 
13,539 shares to meet the requirements of our Dividend Reinvestment and Direct Stock Purchase Plan and 2,007 shares to meet the 
requirements of our share-based programs. No shares of our common stock were accepted as payment for stock option exercises pursuant 
to our Restated Stock Option Plan.

(2)  During the quarter ended December 31, 2017, no shares of our common stock were repurchased pursuant to our Board-Approved share 

repurchase program. For more information on this program, see Note 6.

25

 
 
 
ITEM 6. SELECTED FINANCIAL DATA

In thousands, except per share data

2017

2016

2015

2014

2013

Operating revenues

Net income (loss)

$

762,173

$

675,967

$

723,791

$

754,037

$

758,518

(55,623)

58,895

53,703

58,692

60,538

For the year ended December 31,

Earnings (Loss) per share of common stock:

Basic

Diluted

Dividends paid per share of common stock

$

(1.94) $

2.13

$

1.96

$

2.16

$

(1.94)

1.88

2.12

1.87

1.96

1.86

2.16

1.85

2.24

2.24

1.83

Total assets, end of period

$

3,039,746

$

3,079,801

$

3,069,410

$

3,056,326

$

2,960,808

Total equity

Long-term debt

742,776

683,184

850,497

679,334

780,972

569,445

767,321

613,095

751,872

671,643

26

 
 
 
 
 
ITEM 7. MANAGEMENT'S DISCUSSION AND 
ANALYSIS OF FINANCIAL CONDITION AND 
RESULTS OF OPERATIONS

The following is management’s assessment of Northwest 
Natural Gas Company’s (NW Natural or the Company) 
financial condition, including the principal factors that affect 
results of operations. The discussion refers to our 
consolidated results for the years ended December 31, 
2017, 2016, and 2015. References in this discussion to 
"Notes" are to the Notes to Consolidated Financial 
Statements in Item 8 of this report.

The consolidated financial statements include NW Natural 
and its direct and indirect wholly-owned subsidiaries 
including: 
•  NW Natural Energy, LLC (NWN Energy); 
•  NW Natural Gas Storage, LLC (NWN Gas Storage);
•  Gill Ranch Storage, LLC (Gill Ranch);
•  NNG Financial Corporation (NNG Financial);
•  Northwest Energy Corporation (Energy Corp); 
•  NW Natural Water Company, LLC (NWN Water); and
•  NWN Gas Reserves LLC (NWN Gas Reserves).

We operate in two primary reportable business segments: 
local gas distribution and gas storage. We also have other 
investments and business activities not specifically related 
to one of these two reporting segments, which we 
aggregate and report as other. We refer to our local gas 
distribution business as the utility, and our gas storage 
segment and other as non-utility. Our utility segment 
includes our NW Natural local gas distribution business, 
NWN Gas Reserves, which is a wholly-owned subsidiary of 
Energy Corp, and the utility portion of our Mist underground 
storage facility in Oregon (Mist). Our gas storage segment 
includes NWN Gas Storage, which is a wholly-owned 

subsidiary of NWN Energy, Gill Ranch, which is a wholly-
owned subsidiary of NWN Gas Storage, the non-utility 
portion of Mist, and asset management services. Other 
includes NWN Energy's equity investment in Trail West 
Holding, LLC (TWH), which is pursuing the development of 
a proposed natural gas pipeline through its wholly-owned 
subsidiary, Trail West Pipeline, LLC (TWP), NNG 
Financial's investment in Kelso-Beaver Pipeline (KB 
Pipeline), and NWN Water, which pursuing investments in 
the water sector itself and through its wholly-owned 
subsidiary FWC Merger Sub, Inc. For a further discussion 
of our business segments and other, see Note 4.

NON-GAAP FINANCIAL MEASURES. In addition to presenting 
the results of operations and earnings amounts in total, 
certain financial measures are expressed in cents per share 
or exclude the effects of certain items, which are non-GAAP 
financial measures. We present net income or loss and 
earnings or loss per share adjusted for certain items along 
with the U.S. GAAP measures to illustrate their magnitude 
on ongoing business and operational results. Although the 
excluded amounts are properly included in the 
determination of net income or loss and earnings or loss 
per share under U.S. GAAP, we believe the amount and 
nature these items make period to period comparisons of 
operations difficult or potentially confusing. We use such 
non-GAAP financial measures to analyze our financial 
performance because we believe they provide useful 
information to our investors and creditors in evaluating our 
financial condition and results of operations. Our non-GAAP 
financial measures should not be considered a substitute 
for, or superior to, measures calculated in accordance with 
U.S. GAAP. Reconciliations of the non-GAAP financial 
measures to their closest U.S. GAAP measure used in 
subsequent sections of Item 7 are provided below. 

27

 
NON-GAAP RECONCILIATIONS

In millions, except per share data

Consolidated net income (loss)

Adjustments:

Regulatory environmental disallowance(1)
Impairment of long-lived assets(2)
Tax effects on TCJA(3)

Tax effects on non-GAAP adjustments

Adjusted consolidated net income

Utility net income (loss)

Adjustments:

Regulatory environmental disallowance(1)
Tax effects on TCJA(3)

Tax effects on non-GAAP adjustments

Adjusted utility net income

Gas storage net income (loss)

Adjustments:

Impairment of long-lived assets(2)
Tax effects on TCJA(3)

Tax effects on non-GAAP adjustments

Adjusted gas storage net income

Other net income (loss)

Adjustments:

Tax effects on TCJA(3)

2017

2016

2015

Amount

Per Share

Amount

Per Share

Amount

Per Share

$ (55.6)

$

(1.94)

$

58.9

$

2.12

$

53.7

$

1.96

$

$

—

192.5

(21.4)

(51.0)

64.5

60.5

—

1.0

—

$

61.5

$ (116.2)

192.5

(21.9)

(51.0)

3.4

0.1

$

$

$

$

$

$

$

$

—

6.71

(0.75)

(1.78)

2.24

2.11

—

0.03

—

2.14

(4.05)

6.71

(0.76)

(1.78)

$

$

$

$

3.3

—

—

(1.3)

60.9

54.6

3.3

—

(1.3)

56.6

4.3

—

—

—

$

$

$

$

0.12

—

—

(0.05)

2.19

1.96

0.12

—

(0.05)

2.03

0.16

—

—

—

$

$

$

$

0.12

$

4.3

$

0.16

$

0.2

— $

— $

— $

0.1

15.0

0.55

—

—

(5.9)

62.8

53.4

15.0

—

(5.9)

62.5

0.2

—

—

—

$

$

$

$

$

$

—

—

(0.22)

2.29

1.95

0.55

—

(0.22)

2.28

0.01

—

—

—

0.01

—

—

—

(0.6)

(0.02)

—

—

—

Adjusted other net income (loss)

$

(0.5)

$

(0.02)

$

— $

— $

0.1

$

(1)     Regulatory environmental disallowance of $3.3 million in 2016 includes $2.8 million recorded in utility other income (expense), net and $0.5 

million recorded in utility operations and maintenance expense. Regulatory environmental disallowance of $15.0 million in 2015 is recorded in 
utility operations and maintenance expense. The tax effect of both years' adjustments are calculated using a combined federal and state 
statutory rate of 39.5%. EPS amounts for the 2016 and 2015 adjustments are calculated using diluted shares of 27.8 million and 27.4 million, 
respectively, as shown on our Consolidated Statements of Comprehensive Income (Loss).

(2)     Non-cash impairment of long-lived assets at the Gill Ranch Facility of $192.5 million was recorded on December 31, 2017. The tax effect of 

this adjustment is calculated using our new combined federal and state statutory tax rate of 26.5%. EPS amounts are calculated using diluted 
shares of 28.7 million as shown on our Consolidated Statements of Comprehensive Income (Loss). See Part II, Item 7, "Application of Critical 
Accounting Policies and Estimates—Impairment of Long-Lived Assets" for additional information on the impairment analysis.

(3)     Non-cash Tax Cuts and Jobs Act (TCJA) benefit (expense) of $21.4 million was recorded in income tax expense (benefit) in the fourth quarter 
of 2017 as a result of the federal tax rate changing from 35% to 21% effective December 22, 2017. EPS amounts are calculated using diluted 
shares of 28.7 million as shown on our Consolidated Statements of Comprehensive Income (Loss), and the TCJA impacts in the segments 
and other may not correlate exactly to the consolidated amount due to rounding. See Note 9 for additional information on TCJA.

28

EXECUTIVE SUMMARY

We manage our business and strategic initiatives with a 
long-term view of providing natural gas service safely and 
reliably to customers, working with regulators on key policy 
initiatives, and remaining focused on growing our business. 
See "2018 Outlook" below for more information. Highlights 
for the year include:
• 

added over 12,700 customers in 2017 for a growth rate 
of 1.8% at December 31, 2017;
invested $214 million in our distribution system and 
facilities for growth and reliability;
completed key components of the North Mist Gas 
Storage Expansion Project with $107 million capital 

• 

• 

Key financial highlights include: 

In millions, except per share data

Consolidated net income (loss)

Adjusted consolidated net income(1)

Utility margin

• 

• 

• 

• 

expenditures incurred as of December 31, 2017, with 
an additional $20 to $30 million expected in 2018;
ranked first in the West in the 2017 J.D. Powers' Gas 
Utility Residential Customer Satisfaction Study and Gas 
Utility Business Customer Satisfaction Study;
filed for a general rate increase in Oregon for first time 
in six years; 
delivered increasing dividends for the 62nd consecutive 
year; and
announced our intent to expand into the regulated 
water utility sector by entering into agreements to 
acquire two small privately owned water utilities.

2017

2016

2015

Amount

Per Share

Amount

Per Share

Amount

Per Share

$ (55.6)

$

64.5

$ 392.6

$

$

(1.94)

2.24

$

$

58.9

60.9

$

$

2.12

2.19

$ 376.6

$

$

$

53.7

62.8

$

$

1.96

2.29

371.4

Gas storage operating revenues
(1)     See the Non-GAAP Reconciliations table at the beginning of Item 7 for a reconciliation of this non-GAAP measure to its closest U.S.GAAP 

23.6

25.3

21.4

$

$

$

measure.

2017 COMPARED TO 2016. Consolidated net loss was $55.6 
million compared to consolidated net income of $58.9 million 
in 2016, including $192.5 million pre-tax for the impairment 
of long-lived assets at the Gill Ranch Facility and the $21.4 
million benefit associated with TCJA in 2017, and the $3.3 
million pre-tax regulatory environmental disallowance in 
2016. 

2016 COMPARED TO 2015. Overall, consolidated net income 
increased $5.2 million. The increase was primarily due to 
the $9.1 million after-tax charge from 2015 and a $2.0 
million after-tax charge in 2016 related to the regulatory 
disallowances associated with a February 2015 OPUC 
Order and subsequent Order in our SRRM docket.  

Excluding these items, adjusted consolidated net income 
increased $3.6 million. See the Non-GAAP reconciliations at 
the beginning of Item 7 for additional information. Adjusted 
consolidated net income increased $3.6 million primarily due 
to the following factors: 
• 

a $16.0 million increase in utility margin primarily due to 
customer growth and effects of colder than average 
weather in 2017 compared to warmer than average 
weather in 2016; and
a $3.1 million increase in other income (expense), net 
primarily due an increase of the equity portion of 
AFUDC; partially offset by
a $15.7 million increase in operations and maintenance 
expense driven by higher utility payroll and benefits 
increases, as well as increased safety equipment 
upgrade costs; and
a $1.6 million decrease in gas storage revenues driven 
by lower revenues from our asset management 
agreements for our Mist storage and transportation 
capacity.

• 

• 

• 

Excluding the impact of the non-cash charges from the 
SRRM docket in 2015 and 2016, adjusted consolidated net 
income decreased $1.9 million primarily due to the following 
factors:
• 

a $7.0 million increase in operations and maintenance 
expense primarily due to cost savings initiatives that 
were implemented in the second half of 2015 that did 
not recur in 2016; and 
a $5.5 million decrease in other income (expense), net 
primarily related to the recognition of $5.3 million of 
equity earnings on deferred regulatory asset balances 
as a result of the 2015 OPUC Order; partially offset by
a $5.2 million increase in utility margin primarily due to 
customer growth and gains from gas cost incentive 
sharing; and
a $3.9 million increase in gas storage revenues largely 
due to higher revenues from our asset management 
agreements at both storage facilities and slightly higher 
contract values at the Gill Ranch Facility for the 
2016-17 gas year.

• 

• 

• 

29

 
 
 
 
 
2018 OUTLOOK

Our 2018 goals leverage our resources and history of innovation to continue meeting the evolving needs of customers, 
regulators, and shareholders. Our near-term outlook is centered on following six long-term strategic objectives: 

Deliver Gas

Ensure Safe and Reliable Service

Provide a Superior Customer Experience

Advance Constructive Policies and Regulation

Grow Our Businesses

Enable Utility Growth

Lead in a Low-Carbon Future

Pursue Strategic Investments

SAFETY AND RELIABILITY. Delivering natural gas safely and 
reliably to customers is our first priority. During 2018, we will 
maintain our vigilant focus on safety and emergency 
response through our hands-on scenario-based training for 
our employees, third-party contractors, and local 
authorities. To ensure reliability, resiliency, and safety of our 
infrastructure, we intend to continue to invest in the 
maintenance and necessary upgrades of our pipeline 
system, including multi-year projects to replace end-of-life 
equipment at our Mist storage facility and renovate several 
resource centers. Safety also includes our vigilance in 
maintaining strong cybersecurity defenses and preparing 
for large-scale emergency events, such as seismic hazards 
in our region. 

SUPERIOR CUSTOMER EXPERIENCE. NW Natural has a 
legacy of providing excellent customer service and a long-
standing dedication to continuous improvement, which have 
resulted in consistently high rankings in the J.D. Power and 
Associates customer satisfaction studies. In 2018, we will 
continue to enhance our customers' experience to meet 
their evolving expectations by prioritizing improvements to 
technology which supports our customers' frequent 
interactions and highest value touchpoints. 

POLICIES AND REGULATION. We remain committed to 
working constructively with policymakers and regulators to 
provide the best outcomes for both our customers and 
shareholders. We are working closely with the Oregon 
commission and other stakeholders on several significant 
dockets, including the best way to return TCJA benefits to 
our customers and process our Oregon general rate case, 
which we filed in December 2017. The rate case supports 
the continued investment and maintenance of our system 
for safety, reliability and resiliency. Additionally, we plan to 
file an updated IRP in 2018 to support the long-term 
investments needed for the growth and continued reliability 
of our utility infrastructure. Finally, we will continue working 
with the EPA and other stakeholders on an environmentally 
protective and cost effective clean-up for the Portland 
Harbor Superfund Site.

UTILITY GROWTH. Natural gas is the preferred energy 
choice in our service territory given its efficient, affordable, 
and clean-burning qualities. We are focused on leveraging 
these key attributes to capitalize on our region's strong 
economic growth. We continue to grow our market share in 
the single-family residential sector and capture new 
commercial customers. We have also focused on 
expanding our share of mixed-use developments, a 
growing segment of the multifamily housing market, through 
equipment incentives, streamlined gas infrastructure 
designs, promotional support, and a recently approved new 
tariff. We will continue to pursue growth in all sectors in 
2018. 

LOW-CARBON PATHWAY. The Pacific Northwest and NW 
Natural are deeply committed to a clean energy future. It's 
why we launched our low-carbon initiative to further 
emission savings for both the Company and our 
communities by leveraging our modern pipeline systems in 
new ways, working closely with customers, policymakers 
and regulators, and embracing cutting-edge technology. We 
have partnered with the City of Portland to bring renewable 
natural gas (RNG) onto our system. We expect the entire 
project to be operational in 2019. We will continue helping 
our customers reduce and offset their consumption as we 
support the development of renewable natural gas supply 
and explore other cutting edge solutions to lower the 
carbon intensity of our product, such as power to gas.

STRATEGIC INVESTMENTS. We remain focused on creating 
value in all our businesses. We are investing in the 
regulated utility expansion of our Mist gas storage facility, 
which will provide innovative no-notice gas storage service 
for a local electric company who will use the reliability of 
natural gas to integrate more intermittent renewable energy 
— like solar and wind — into the energy grid. In 2017, we 
announced our intent to expand into the regulated water 
utility sector and will continue pursuing this strategy in 2018 
with a focus on water sector investments that fit our 
conservative risk profile and core competencies. Our 
pursuit of a holding company structure is important to this 
growth strategy. With the OPUC and WUTC approvals for a 
holding company reorganization received, we will be 
focused on seeking shareholder approval for conversion to 
a holding company structure at our 2018 annual 
shareholders' meeting and executing on the conversions in 
late 2018 or early 2019.

30

HOLDING COMPANY

Formation of a Holding Company 
Holding company structures are well-established corporate 
structures, and exist across all industries. In the utility 
industry, holding companies have become the norm, and 
are employed for the same purposes holding companies are 
used in other industries. NW Natural intends to pursue 
formation of a holding company to best position it to be able 
to respond to opportunities and risks in a manner that 
serves the best interests of its shareholders and customers. 
We have received regulatory approval from the OPUC and 
WUTC and expect regulatory approval from the CPUC to 
reorganize into a holding company structure. Our Board of 
Directors has determined to recommend a holding company 
structure to our shareholders for vote at our 2018 Annual 
Shareholders Meeting. If our shareholders approve, the 
Board and Management must take additional actions to 
implement the holding company structure, which we 
currently expect to happen in the latter half of 2018 or at the 
beginning of 2019. To implement a holding company 
structure, NW Natural common stock would be converted or 
exchanged into the same relative percentages of the holding 
company that they own of NW Natural immediately prior to 
the reorganization. The structure currently contemplated 
involves placing a non-operating corporate entity over the 
existing consolidated structure, and “ring-fencing” NW 
Natural as described below to insulate the gas utility from 
the operations of the holding company and its other direct 
and indirect subsidiaries. NW Natural management 
continuously looks for growth opportunities that would build 
on core competencies and match the risk profile that NW 
Natural and its shareholders seek. We believe a holding 
company structure is a more agile and efficient platform 
from which to pursue, finance and oversee new business 
growth opportunities, such as in the water sector. Following 
the formation of the holding company, NW Natural would 
continue to operate as a gas utility subject to the jurisdiction 
of the OPUC and the WUTC.

Holding Company Regulatory Restrictions and Conditions
The regulatory approvals for the formation of a holding 
company require NW Natural and its holding company to 
enter into and file an agreement with the OPUC and the 
WUTC, which includes a number of “ring-fencing” 
conditions. The ring-fencing provisions are designed to 
operate the gas utility business conservatively and insulate 
it from risks associated with other holding company 
businesses. The ring-fencing and other provisions of the 
approvals include the following:
•  NW Natural may not pay dividends or make 

distributions to the holding company if NW Natural’s 
credit ratings and common equity levels fall below 
specified ratings and levels. If NW Natural’s long-term 
secured credit ratings are below A- for S&P and A3 for 
Moody’s, dividends may be issued so long as NW 
Natural’s common equity is 45% or above. If NW 
Natural’s long-term secured credit ratings are below 
BBB for S&P and Baa2 for Moody’s, dividends may be 
issued so long as NW Natural’s common equity is 46% 
or above. Dividends may not be issued if NW Natural’s 
long-term secured credit ratings fall to BB+ or below for 
S&P or Ba1 or below for Moody’s, or if NW Natural’s 
common equity is below 44%. In each case, with the 
common equity level to be determined on a preceding 

31

or projected 13-month basis. 

• 

•  Maintenance of separate credit ratings, long-term debt 
ratings, and preferred stock ratings, if any, by NW 
Natural and its holding company;
In the event NW Natural’s common equity, on a 
preceding or projected basis, falls below 46%, NW 
Natural is required to notify the OPUC, and if the level 
of common equity falls below 44%, file a plan with the 
OPUC to restore its equity to that level. Under the 
WUTC order, the average equity component must not 
exceed 56%;

•  NW Natural must have one director who is independent 
from NW Natural management and from the holding 
company;

•  NW Natural and its subsidiaries will not be permitted to 

hold holding company investments, except under NW 
Natural-sponsored employee benefit plans or employee 
compensation plans;

• 

• 

•  NW Natural must issue one share of preferred stock to 
an independent party and require that NW Natural may 
only file a voluntary petition for bankruptcy if approved 
unanimously by the Board of Directors of NW Natural, 
including the independent director, and by the holder of 
the preferred share;
As is the case currently, NW Natural will be prohibited 
from cross-subsidizing any business, including the 
holding company and its unregulated subsidiaries;  
The costs of the holding company reorganization must 
be separately tracked and not charged or allocated to 
NW Natural, and those costs and all other costs related 
to future business endeavors of the holding company 
must be excluded from NW Natural rate cases. NW 
Natural and its holding company are required to 
guarantee that NW Natural customers will not be 
harmed by any increases in NW Natural costs that 
result from the holding company reorganization, 
including any higher costs of debt or equity, higher 
revenue requirement, tax costs, or rate of return, due to 
the reorganization; and
For three years, NW Natural will be required to provide 
an annual $500,000 credit to Oregon customers and a 
$55,000 credit to Washington customers. Cost-savings 
over $50,000 that are allocable to NW Natural as a 
result of holding company acquisition activity will be 
deferred and credited to Oregon and Washington 
customers until after NW Natural’s next general rate 
case following the Company’s 2017 general rate case.

• 

DIVIDENDS

Dividend highlights include:  

Per common share

Dividends paid

2017

2016

2015

$ 1.8825

$ 1.8725

$ 1.8625

In January 2018, the Board of Directors declared a quarterly 
dividend on our common stock of $0.4725 per share, 
payable on February 15, 2018, to shareholders of record on 
January 31, 2018, reflecting an indicated annual dividend 
rate of $1.89 per share.

RESULTS OF OPERATIONS

Regulatory Matters

Regulation and Rates 
UTILITY. Our utility business is subject to regulation by the 
OPUC, WUTC, and FERC with respect to, among other 
matters, rates and terms of service. The OPUC and WUTC 
also regulate the system of accounts and issuance of 
securities by our utility. In 2017, approximately 89% of our 
utility gas customers were located in Oregon, with the 
remaining 11% in Washington. Earnings and cash flows 
from utility operations are largely determined by rates set in 
general rate cases and other proceedings in Oregon and 
Washington. They are also affected by the local economies 
in Oregon and Washington, the pace of customer growth in 
the residential, commercial, and industrial markets, and our 
ability to remain price competitive, control expenses, and 
obtain reasonable and timely regulatory recovery of our 
utility-related costs, including operating expenses and 
investment costs in utility plant and other regulatory assets. 
See "Most Recent General Rate Cases" below.

GAS STORAGE. Our gas storage business is subject to 
regulation by the OPUC, WUTC, CPUC, and FERC with 
respect to, among other matters, rates and terms of service. 
The OPUC and CPUC also regulate the issuance of 
securities, system of accounts, and regulate intrastate 
storage services. The FERC regulates interstate storage 
services. The FERC uses a maximum cost of service model 
which allows for gas storage prices to be set at or below the 
cost of service as approved by each agency in their last 
regulatory filing. The OPUC Schedule 80 rates are tied to 
the FERC rates, and are updated whenever we modify our 
FERC maximum rates. The CPUC regulates Gill Ranch 
under a market-based rate model which allows for the price 
of storage services to be set by the marketplace. In 2017, 
approximately 70% of our storage revenues were derived 
from FERC, Oregon, and Washington regulated operations 
and approximately 30% from California operations.

Most Recent General Rate Cases  
OREGON. Effective November 1, 2012, the OPUC 
authorized rates to customers based on an ROE of 9.5%, an 
overall rate of return of 7.78%, and a capital structure of 
50% common equity and 50% long-term debt. 

WASHINGTON. Effective January 1, 2009, the WUTC 
authorized rates to customers based on an ROE of 10.1% 
and an overall rate of return of 8.4% with a capital structure 
of 51% common equity, 5% short-term debt, and 44% long-
term debt.

FERC. We are required under our Mist interstate storage 
certificate authority and rate approval orders to file every 
five years either a petition for rate approval or a cost and 
revenue study to change or justify maintaining the existing 
rates for our interstate storage services. In December 2013, 
we filed a rate petition, which was approved in 2014, and 
allows for the maximum cost-based rates for our interstate 
gas storage services. These rates were effective January 1, 
2014, with the rate changes having no significant impact on 
our revenues. In January 2018, various state parties filed a 
request with the FERC to adjust the revenue requirements 

32

of public utilities to reflect the recent reduction in the federal 
corporate income tax rate and other impacts resulting from 
the TCJA. We will monitor this request and work the FERC 
to evaluate the potential impact to these approved rates.

We continuously monitor the utility and evaluate the need 
for a rate case. In December 2017, we filed a rate case in 
Oregon with the OPUC. For additional information, see 
"Regulatory Proceeding Updates—Rate Case" below. 

Regulatory Proceeding Updates
During 2017, we were involved in the regulatory activities 
discussed below. 

HEDGING. In 2014, the OPUC opened a docket to discuss 
broader gas hedging practices across gas utilities in 
Oregon. In January 2018, the OPUC accepted the parties' 
proposal to follow a uniform process to address any future 
proposed long-term hedges and closed the docket.

The WUTC also conducted an investigation into the hedging 
practices of gas utilities operating in Washington and 
considered whether it should require gas utilities to 
implement certain hedging practices. The WUTC issued and 
outlined their policy in March 2017. The policy supports risk-
responsive hedging strategies that are adaptable to 
variability in the market and required gas utilities to submit 
with their 2017 PGA a preliminary hedging plan that outlines 
the utilities' intended path to incorporate risk-responsive 
hedging strategies. Beginning with the 2018 PGA, gas 
utilities must submit an annual comprehensive hedging plan 
that supports integration of risk responsive strategies into 
their hedging framework. Beginning with the 2019 PGA 
filing, utilities must provide a full strategy implementation 
plan for year 2020 and beyond. As directed by the WUTC, 
we submitted our preliminary hedging plan with our 2017 
PGA in September 2017, and plan to submit our annual 
comprehensive hedging plan with our 2018 PGA.

INTERSTATE STORAGE AND OPTIMIZATION SHARING. We 
received an Order from the OPUC in March 2015 on their 
review of the current revenue sharing arrangement that 
allocates a portion of the net revenues generated from non-
utility Mist storage services and third-party asset 
management services to utility customers. The Order 
requires a third-party cost study to be performed and the 
results of the cost study may initiate a new docket or the re-
opening of the original docket. In 2017, a third-party 
consultant completed a cost study. We will continue to work 
with all stakeholders as we review this completed study, and 
expect resolution of this docket in 2018.

INTEGRATED RESOURCE PLAN (IRP). We file a full IRP with 
Oregon and Washington bi-annually and file updates 
between filings. Our last full IRPs were filed in 2016, and we 
received a letter of compliance from the WUTC in December 
of 2016 and acknowledgment by the OPUC in February of 
2017. The IRP included analysis of different growth 
scenarios and corresponding resource acquisition 
strategies. The analysis is needed to develop supply and 
demand resource requirements, consider uncertainties in 
the planning process, and establish a plan for providing 
reliable and low cost natural gas service. We anticipate filing 
our next full IRP in 2018.

DEPRECIATION STUDY. Under OPUC regulations, the utility 
is required to file a depreciation study every five years to 
update or justify maintaining the existing depreciation rates. 
In December 2016, we filed the required depreciation study 
with the Commission. In September 2017, the parties to the 
docket filed a settlement with the Commission requesting 
approval of updated depreciation rates negotiated with the 
parties. In January 2018, OPUC issued an order adopting 
the stipulation. The depreciation rates included in the 
stipulation do not materially change our current depreciation 
rates. 

HOLDING COMPANY APPLICATION. In February 2017, we 
filed applications with the OPUC, WUTC, and CPUC for 
approval to reorganize under a holding company structure. 
In 2017, the OPUC and WUTC approved our applications 
subject to certain restrictions or "ring-fencing" provisions 
applicable to NW Natural, the entity that currently, and 
would continue to, house our utility operations, and the 
holding company. We continue to work with the CPUC, and 
expect resolutions by the end of the first quarter of 2018.

MULTI-FAMILY TARIFF. In June 2017, we filed a request with 
the OPUC to create a multi-family tariff to establish an 
optional program to serve the mixed-use, multi-family 
residential market. Under the tariff, NW Natural will provide 
upfront incentives for builders to offset the initial cost of 
installing natural gas piping to individual units, and then 
recover the costs of the incentives through a fixed charge on 
the customer's monthly bills. In July 2017, the OPUC 
approved the tariff allowing us to further serve the multi-
family customer sector. 

TAX REFORM DEFERRAL. In December 2017, we filed 
applications with the OPUC and WUTC to defer the overall 
net benefit associated with the TCJA that was enacted on 
December 22, 2017 with a January 1, 2018 effective date. 
We anticipate the impacts from the TCJA will accrue to our 
customers in a manner approved by the Commissions. We 
will continue to work with the OPUC and WUTC on this 
throughout 2018. See Note 9 for more information on TCJA.

REGULATED WATER UTILITY. In December 2017, we entered 
into agreements to acquire two privately-owned water 
utilities: Salmon Valley Water Company, based in Welches, 
Oregon, and Falls Water Company, based in Idaho Falls, 
Idaho. These transactions are subject to certain conditions, 
including approvals from the OPUC and the Idaho Public 
Utilities Commission (IPUC), respectively. In January 2018, 
we filed our application with the OPUC to acquire Salmon 
Valley Water Company and filed with the IPUC in February 
2018 to acquire Falls Water Company. We do not expect 
these transactions or their continuing operations to have a 
material financial impact. We continue to work with the 
OPUC and IPUC and anticipate receiving approvals and 
completing these acquisitions in 2018.

GENERAL RATE CASE. On December 29, 2017, we filed an 
Oregon general rate case requesting a 6% revenue 
increase, after an adjustment for the conservation tariff 
deferral, to continue operating and maintaining our 
distribution system and continue providing safe, reliable 
service to our customers. Our December general rate case 
filing was based on the following:

• 

• 
• 
• 
• 

forward test year from November 1, 2018 through 
October 31, 2019;
capital structure of 50% debt and 50% equity;
return on equity of 10.0%;
cost of capital of 7.62%; and
rate base of $1.19 billion, an increase of $304 million 
since the last Oregon rate case in 2012.

The general rate case filing in December 2017 does not 
include the benefit to customers’ rates of the newly passed 
federal tax legislation. In the coming months, we will be 
working with the OPUC to determine how to return these 
benefits to customers, and we expect to amend or refile our 
rate case to incorporate the benefit of the TCJA, which 
would likely lower the original revenue requirement 
requested. It is possible through this rate case proceeding 
or another proceeding that the OPUC will also determine 
how to treat historical deferred tax liabilities, which may 
result in additional changes to our rate case request as well. 
The general rate case review and approval process could 
take up to 10 months with new rates anticipated to be 
effective November 1, 2018. 

Rate Mechanisms
During 2017, our approved rates and recovery mechanisms 
for each service area included:

Authorized Rate Structure:

ROE

ROR

Oregon

Washington

9.5%

7.8%

10.1%

8.4%

Debt/Equity Ratio

50%/50%

49%/51%

Key Regulatory Mechanisms:

PGA

Gas Cost Incentive Sharing

Decoupling

WARM

Environmental Cost Deferral

SRRM

Pension Balancing

Interstate Storage Sharing

X

X

X

X

X

X

X

X

X

X

X

PURCHASED GAS ADJUSTMENT. Rate changes are 
established for the utility each year under PGA mechanisms 
in Oregon and Washington to reflect changes in the 
expected cost of natural gas commodity purchases. This 
includes gas costs under spot purchases as well as contract 
supplies, gas costs hedged with financial derivatives, gas 
costs from the withdrawal of storage inventories, the 
production of gas reserves, interstate pipeline demand 
costs, temporary rate adjustments, which amortize balances 
of deferred regulatory accounts, and the removal of 
temporary rate adjustments effective for the previous year.

In September 2017, we filed our PGA and received OPUC 
and WUTC approval in October 2017. PGA rate changes 
were effective November 1, 2017. The rate changes 
decreased the average monthly bills of residential 
customers by approximately 6.4% and 3.1% in Oregon and 
Washington, respectively. The decrease in Oregon reflected 

33

customers' portion of adjustments mainly for the effect of 
changes in wholesale natural gas costs and for a portion of 
WARM amounts that exceeded the maximum monthly 
allowable amount to be returned to customers during the 
2016-17 gas year. Oregon rates were offset by adjustments 
related to our energy efficiency programs and additional 
annual adjustments based on ongoing orders with the 
OPUC. Washington rates reflected the effect of changes in 
wholesale natural gas costs.

Each year, we typically hedge gas prices on a portion of our 
utility's annual sales requirement based on normal weather, 
including both physical and financial hedges. We entered 
the 2017-18 gas year with our forecasted sales volumes 
hedged at 49% in financial swap and option contracts and 
26% in physical gas supplies. For additional hedging 
matters from the WUTC and OPUC, see "Regulatory 
Proceeding Updates—Hedging" above.

As of December 31, 2017, we have also hedged future gas 
years with approximately 24% for the 2018-19 gas year and 
between 4% and 11% over the subsequent five gas years 
for utility's annual sales requirements based on normal 
weather. Our hedge levels are subject to change based on 
actual load volumes, which depend, to a certain extent, on 
weather, economic conditions, and estimated gas reserve 
production. Also, our gas storage inventory levels may 
increase or decrease with storage expansion, changes in 
storage contracts with third parties, variations in the heat 
content of the gas, and/or storage recall by the utility. 

Under the current PGA mechanism in Oregon, there is an 
incentive sharing provision whereby we are required to 
select each year an 80% deferral or a 90% deferral of higher 
or lower actual gas costs compared to estimated PGA 
prices, such that the impact on current earnings from the 
incentive sharing is either 20% or 10% of the difference 
between actual and estimated gas costs, respectively. For 
the 2016-17 and 2017-18 gas years, we selected the 90% 
deferral option. Under the Washington PGA mechanism, we 
defer 100% of the higher or lower actual gas costs, and 
those gas cost differences are passed on to customers 
through the annual PGA rate adjustment.

EARNINGS TEST REVIEW. We are subject to an annual 
earnings review in Oregon to determine if the utility is 
earning above its authorized ROE threshold. If utility 
earnings exceed a specific ROE level, then 33% of the 
amount above that level is required to be deferred or 
refunded to customers. Under this provision, if we select the 
80% deferral gas cost option, then we retain all of our 
earnings up to 150 basis points above the currently 
authorized ROE. If we select the 90% deferral option, then 
we retain all of our earnings up to 100 basis points above 
the currently authorized ROE. For the 2015-16 gas year, we 
selected the 80% deferral option. For the 2016-17 and 
2017-18 gas years, we selected the 90% deferral option. 
The ROE threshold is subject to adjustment annually based 
on movements in long-term interest rates. For calendar 
years 2015, 2016, and 2017, the ROE threshold was 
10.60%, 11.06%, and 10.66%, respectively. There were no 
refunds required for 2015 and 2016. We do not expect a 
refund for 2017 based on our results and anticipate filing the 
2017 earnings test in May 2018. 

34

GAS RESERVES. In 2011, the OPUC approved the Encana 
gas reserves transaction to provide long-term gas price 
protection for our utility customers and determined our costs 
under the agreement would be recovered on an ongoing 
basis through our annual PGA mechanism. Gas produced 
from our interests is sold at then prevailing market prices, 
and revenues from such sales, net of associated operating 
and production costs and amortization, are included in our 
cost of gas. The cost of gas, including a carrying cost for the 
rate base investment made under the original agreement, is 
included in our annual Oregon PGA filing, which allows us to 
recover these costs through customer rates. Our net 
investment under the original agreement earns a rate of 
return.

In 2014, we amended the original gas reserves agreement 
in response to Encana's sale of its interest in the Jonah field 
located in Wyoming to Jonah Energy. Under our amended 
agreement with Jonah Energy, we have the option to invest 
in additional wells on a well-by-well basis with drilling costs 
and resulting gas volumes shared at our amended 
proportionate working interest for each well in which we 
invest. Volumes produced from the additional wells drilled 
after our amended agreement are included in our Oregon 
PGA at a fixed rate of $0.4725. We did not have the 
opportunity to participate in additional wells in 2015, 2016, 
or 2017. 

DECOUPLING. In Oregon, we have a decoupling 
mechanism. Decoupling is intended to break the link 
between utility earnings and the quantity of gas consumed 
by customers, removing any financial incentive by the utility 
to discourage customers’ efforts to conserve energy.
The Oregon decoupling mechanism was reauthorized and 
the baseline expected usage per customer was set in the 
2012 Oregon general rate case. This mechanism employs a 
use-per-customer decoupling calculation, which adjusts 
margin revenues to account for the difference between 
actual and expected customer volumes. The margin 
adjustment resulting from differences between actual and 
expected volumes under the decoupling component is 
recorded to a deferral account, which is included in the 
annual PGA filing. In Washington, customer use is not 
covered by such a tariff. 

WARM. In Oregon, we have an approved weather 
normalization mechanism, which is applied to residential 
and commercial customer bills. This mechanism is designed 
to help stabilize the collection of fixed costs by adjusting 
residential and commercial customer billings based on 
temperature variances from average weather, with rate 
decreases when the weather is colder than average and 
rate increases when the weather is warmer than average. 
The mechanism is applied to bills from December through 
May of each heating season. The mechanism adjusts the 
margin component of customers’ rates to reflect average 
weather, which uses the 25-year average temperature for 
each day of the billing period. Daily average temperatures 
and 25-year average temperatures are based on a set point 
temperature of 59 degrees Fahrenheit for residential 
customers and 58 degrees Fahrenheit for commercial 
customers. The collections of any unbilled WARM amounts 
due to tariff caps and floors are deferred and earn a carrying 
charge until collected in the PGA the following year. This 
weather normalization mechanism was reauthorized in the 

2012 Oregon general rate case without an expiration date. 
Residential and commercial customers in Oregon are 
allowed to opt out of the weather normalization mechanism, 
and as of December 31, 2017, 9% of total customers had 
opted out. We do not have a weather normalization 
mechanism approved for residential and commercial 
Washington customers, which account for about 11% of total 
customers. See "Business Segments—Local Gas 
Distribution Utility Operations" below.

INDUSTRIAL TARIFFS. The OPUC and WUTC have 
approved tariffs covering utility service to our major 
industrial customers, which are intended to give us certainty 
in the level of gas supplies we need to acquire to serve this 
customer group. The approved terms include, among other 
things, an annual election period, special pricing provisions 
for out-of-cycle changes, and a requirement that industrial 
customers complete the term of their service election under 
our annual PGA tariff.

ENVIRONMENTAL COST DEFERRAL AND SRRM. We have a 
SRRM through which we track and have the ability to 
recover past deferred and future prudently incurred 
environmental remediation costs allocable to Oregon, 
subject to an earnings test. 

Under the SRRM collection process, there are three types of 
deferred environmental remediation expense:
• 

Pre-review - This class of costs represents remediation 
spend that has not yet been deemed prudent by the 
OPUC. Carrying costs on these remediation expenses 
are recorded at our authorized cost of capital. We 
anticipate the prudence review for annual costs and 
approval of the earnings test prescribed by the OPUC 
to occur by the third quarter of the following year. 
Post-review - This class of costs represents 
remediation spend that has been deemed prudent and 
allowed after applying the earnings test, but is not yet 
included in amortization. We earn a carrying cost on 
these amounts at a rate equal to the five-year treasury 
rate plus 100 basis points. 
Amortization - This class of costs represents amounts 
included in current customer rates for collection and is 
generally calculated as one-fifth of the post-review 
deferred balance. We earn a carrying cost equal to the 
amortization rate determined annually by the OPUC, 
which approximates a short-term borrowing rate. We 
included $7.4 million and $10.0 million of deferred 
remediation expense approved by the OPUC for 
collection during the 2017-18 and 2016-17 PGA years, 
respectively.

• 

• 

In addition, the SRRM also provides for the annual 
collection of $5.0 million from Oregon customers through a 
tariff rider. As we collect amounts from customers, we 
recognize these collections as revenue and separately 
amortize an equal and offsetting amount of our deferred 
regulatory asset balance through the environmental 
remediation operating expense line shown separately in the 
operating expense section of our Consolidated Statement of 
Comprehensive Income (Loss). See Note 15 for more 
information on our environmental matters.

The SRRM earnings test is an annual review of our adjusted 
utility ROE compared to our authorized utility ROE, which is 

35

currently 9.5%. To apply the earnings test first we must 
determine what if any costs are subject to the test through 
the following calculation:

Annual spend
Less: $5.0 million base rate rider(1)
          Prior year carry-over(2)
          $5.0 million insurance + interest on insurance

Total deferred annual spend subject to earnings test

Less: over-earnings adjustment, if any
Add:  deferred interest on annual spend(3)
Total amount transferred to post-review

(1)   Base rate rider went into Oregon customer rates beginning 

November 1, 2015.

(2)   Prior year carry-over results when the prior year amount 

transferred to post-review is negative. The negative amount is 
carried over to offset annual spend in the following year. 
(3)   Deferred interest is added to annual spend to the extent the 

spend is recoverable. 

To the extent the utility earns at or below its authorized 
ROE, the total amount transferred to post-review is 
recoverable through the SRRM. To the extent the utility 
earns more than its authorized ROE in a year, the amount 
transferred to post-review would be reduced by those 
earnings that exceed its authorized ROE.

For 2017, we have performed this test, which we anticipate 
submitting to the OPUC in May 2018, and we do not expect 
an earnings test adjustment for 2017.  

The WUTC has also previously authorized the deferral of 
environmental costs, if any, that are appropriately allocated 
to Washington customers. This Order was effective in 
January 2011 with cost recovery and carrying charges on 
amount deferred for costs associated with services provided 
to Washington customers to be determined in a future 
proceeding. Annually, or more often if circumstances 
warrant, we review all regulatory assets for recoverability. If 
we should determine all or a portion of these regulatory 
assets no longer meet the criteria for continued application 
of regulatory accounting, then we would be required to 
write-off the net unrecoverable balances against earnings in 
the period such a determination was made.

PENSION COST DEFERRAL AND PENSION BALANCING 
ACCOUNT. The OPUC permits us to defer annual pension 
expenses above the amount set in rates, with recovery of 
these deferred amounts through the implementation of a 
balancing account, which includes the expectation of higher 
and lower pension expenses in future years. Our recovery of 
these deferred balances includes accrued interest on the 
account balance at the utility’s authorized rate of return. 
Future years’ deferrals will depend on changes in plan 
assets and projected benefit liabilities based on a number 
of key assumptions and our pension contributions. Pension 
expense deferrals, excluding interest, were $6.5 million, 
$6.3 million, and $8.2 million in 2017, 2016 and 2015, 
respectively. 

INTERSTATE STORAGE AND OPTIMIZATION SHARING. On an 
annual basis, we credit amounts to Oregon and Washington 
customers as part of our regulatory incentive sharing 

 
  
 
 
mechanism related to net revenues earned from Mist gas 
storage and asset management activities. Generally, 
amounts are credited to Oregon customers in June, while 
credits are given to customers in Washington through 
reductions in rates through the annual PGA filing in 
November.

Excluding these items, adjusted utility net income increased 
$5.0 million, or $0.11 per share. The primary factors 
contributing to this increase in adjusted utility net income 
were as follows:
• 

a $16.0 million increase in utility margin primarily due 
to:

The following table presents the credits to customers: 

In millions

Oregon utility
customer credit

Washington utility
customer credit

2017

2016

2015

$

11.7

$

9.4

$

1.0

1.0

9.6

0.8

Business Segments - Local Gas Distribution Utility 
Operations
Utility margin results are primarily affected by customer 
growth, revenues from rate-base additions, and, to a certain 
extent, by changes in delivered volumes due to weather and 
customers’ gas usage patterns because a significant portion 
of our utility margin is derived from natural gas sales to 
residential and commercial customers. In Oregon, we have 
a conservation tariff (also called the decoupling 
mechanism), which adjusts utility margin up or down each 
month through a deferred regulatory accounting adjustment 
designed to offset changes resulting from increases or 
decreases in average use by residential and commercial 
customers. We also have a weather normalization tariff in 
Oregon, WARM, which adjusts customer bills up or down to 
offset changes in utility margin resulting from above- or 
below-average temperatures during the winter heating 
season. Both mechanisms are designed to reduce, but not 
eliminate, the volatility of customer bills and our utility’s 
earnings. See "Regulatory Matters—Rate Mechanisms" 
above. 

Utility segment highlights include:  

Dollars and therms in
millions, except EPS data

2017

2016

2015

Utility net income

$

60.5

$

54.6

$

53.4

Adjusted utility net 
income(1)

EPS - utility segment

Adjusted EPS - utility 
segment(1)

61.5

2.11

2.14

56.6

1.96

2.03

62.5

1.95

2.28

Gas sold and delivered
(in therms)
Utility margin(2)
371.4
(1) See the Non-GAAP Reconciliations table at the beginning of Item 
7 for a reconciliation of this non-GAAP measure to its closest 
U.S.GAAP measure.

1,240

376.6

392.6

1,085

1,029

$

$

$

(2)  See Utility Margin Table below for a reconciliation and additional 

detail. 

2017 COMPARED TO 2016. Utility net income was $60.5 
million in 2017 compared to $54.6 million in 2016, which 
includes the $1.0 million loss associated with the TCJA in 
2017 and the after-tax $2.0 million regulatory environmental 
disallowance in 2016. See the Non-GAAP reconciliations at 
the beginning of Item 7 for additional information.

36

a $6.8 million increase from customer growth; 
partially offset by
a $2.7 million decrease in gains in gas cost 
incentive sharing due to actual gas prices being 
lower than those estimated in the 2016-17 PGA, 
but not by the same magnitude as in the prior 
period.
a portion of the remaining increase was due to the 
effects of colder than average weather in 2017 
compared to warmer than average weather in 
2016.

• 

• 

• 

a $3.1 million increase in other income (expense), net, 
primarily due to an increase in the equity portion of 
AFUDC in 2017; partially offset by
a $9.5 million increase in operations and maintenance 
expense driven largely from payroll and benefits due to 
increased headcount, general salary increases, and 
increased safety equipment update costs; and 
a $3.4 million increase in depreciation expense 
primarily due to additional capital expenditures.

Total utility volumes sold and delivered in 2017 increased 
14% over 2016 primarily due to the impact of weather that 
was 28% colder than the prior period and 7% colder than 
average.

2016 COMPARED TO 2015. The primary factors contributing 
to the $1.2 million, or $0.01 per share, increase in utility net 
income were as follows:
• 

a $5.2 million increase in utility margin primarily due to:
a $5.7 million increase from customer growth; 
a $0.8 million increase from gains in gas cost 
incentive sharing resulting from lower gas prices 
than those estimated in the PGA; partially offset by
a $1.3 million decrease due to lower contributions 
from our gas reserve investments, which 
decreased due to amortization.

• 

• 

• 

an $8.3 million decrease in operations and 
maintenance expense primarily due to the 
environmental disallowance recognized in 2015, offset 
in part by increases in payroll costs due to additional 
headcount and general pay increases along with 
increased non-payroll costs for professional services 
and contract work; partially offset by
an $8.7 million, decrease in other income (expense), 
net, primarily due to the environmental interest 
disallowance recognized in 2016 and the recognition of 
$5.3 million of equity earnings on deferred regulatory 
asset balances in 2015; and 
a $1.9 million, increase in depreciation expense 
primarily due to additional capital expenditures. 

Total utility volumes sold and delivered in 2016 increased 
5% over 2015 primarily due to comparatively colder weather 
in the first quarter during our peak heating season and 
colder weather in December 2016. 

                                                                                                                                                                                                                              
 
 
 
 
 
 
UTILITY MARGIN TABLE. The following table summarizes the composition of utility gas volumes, revenues, and cost of sales: 

In thousands, except degree day and customer data

2017

2016

2015

Utility volumes (therms):

Residential and commercial sales

Industrial sales and transportation

740,369

499,924

609,222

475,774

570,728

457,884

Total utility volumes sold and delivered

1,240,293

1,084,996

1,028,612

Favorable/(Unfavorable)

2017 vs.
2016

2016 vs.
2015

131,147

24,150

155,297

38,494

17,890

56,384

Utility operating revenues:

Residential and commercial sales

Industrial sales and transportation

Other revenues

Less: Revenue taxes

Total utility operating revenues

Less: Cost of gas

Less: Environmental remediation expense

Utility margin

Utility margin:(1)

Residential and commercial sales

Industrial sales and transportation

Miscellaneous revenues

Gain from gas cost incentive sharing

Other margin adjustments

Utility margin

Degree days
Average(2)

Actual
Percent colder (warmer) than average weather(2)

Customers - end of period:

Residential customers

Commercial customers

Industrial customers

$ 684,214

$ 604,390

$ 644,835

$

79,824

$ (40,445)

63,925

3,872

19,069

732,942

325,019

15,291

59,386

3,812

17,111

650,477

260,588

13,298

71,495

3,914

18,034

702,210

327,305

3,513

$ 392,632

$ 376,591

$ 371,392

$ 355,736

$ 338,060

$ 334,134

31,847

30,989

30,081

3,865

1,237

(53)

3,796

3,960

(214)

3,913

3,182

82

4,539

60

1,958

82,465

(12,109)

(102)

(923)

(51,733)

(64,431)

66,717

$

$

$

$

(1,993)

16,041

17,676

858

69

(2,723)

161

(9,785)

5,199

3,926

908

(117)

778

(296)

$ 392,632

$ 376,591

$ 371,392

$

16,041

$

5,199

4,240

4,553

4,256

3,551

4,240

3,458

(16)

28%

16

3%

7%

(17)%

(18)%

668,803

656,855

646,841

11,948

10,014

68,050

1,021

67,278

1,013

66,584

1,003

772

8

694

10

Total number of customers

737,874

725,146

714,428

12,728

10,718

Customer growth:

Residential customers

Commercial customers

Industrial customers

Total customer growth

1.8%

1.1%

0.8%

1.8%

1.5 %

1.0 %

1.0 %

1.5 %

(1)  Amounts reported as margin for each category of customers are operating revenues, which are net of revenue taxes, less cost of gas and 

environmental remediation expense.

(2)  Average weather represents the 25-year average of heating degree days, as determined in our 2012 Oregon general rate case.

37

Residential and Commercial Sales
The primary factors that impact results of operations in the 
residential and commercial markets are customer growth, 
seasonal weather patterns, energy prices, competition from 
other energy sources, and economic conditions in our 
service areas. The impact of weather on margin is 
significantly reduced through our weather normalization 
mechanism in Oregon; approximately 80% of our total 
customers are covered under this mechanism. The 
remaining customers either opt out of the mechanism or are 
located in Washington, which does not have a similar 
mechanism in place. For more information on our weather 
mechanism, see "Regulatory Matters—Rate Mechanisms—
Weather Normalization Mechanism" above.

Residential and commercial sales highlights include:

In millions

Volumes (therms):

Residential sales

Commercial sales

Total volumes

Operating revenues:

2017

2016

2015

465.2

275.2

740.4

379.2

230.0

609.2

350.9

219.8

570.7

Residential sales

$

455.9

$

404.3

$

424.6

• 

partially offset by a 7% increase in sales volumes; and
utility margin increased $4.0 million, due to both 
residential and commercial customer growth offset by 
lower contributions from our gas reserve investments, 
which decreased due to amortization. 

Industrial Sales and Transportation
Industrial customers have the option of purchasing sales or 
transportation services from the utility. Under the sales 
service, the customer buys the gas commodity from the 
utility. Under the transportation service, the customer buys 
the gas commodity directly from a third-party gas marketer 
or supplier. Our gas commodity cost is primarily a pass-
through cost to customers; therefore, our profit margins are 
not materially affected by an industrial customer's decision 
to purchase gas from us or from third parties. Industrial and 
large commercial customers may also select between firm 
and interruptible service options, with firm services generally 
providing higher profit margins compared to interruptible 
services. To help manage gas supplies, our industrial tariffs 
are designed to provide some certainty regarding industrial 
customers' volumes by requiring an annual service election 
which becomes effective November 1, special charges for 
changes between elections, and in some cases, a minimum 
or maximum volume requirement before changing options. 

228.3

200.1

220.2

Industrial sales and transportation highlights include:

$

684.2

$

604.4

$

644.8

In millions

2017

2016

2015

Commercial sales

Total operating
revenues

Utility margin:

Residential:

Sales

Weather normalization

Decoupling

Total residential utility
margin

Commercial:

Sales

Weather normalization

Decoupling

Total commercial utility
margin

$

262.1

$

223.2

$

211.6

(11.9)

(2.4)

12.7

0.8

14.0

7.2

247.8

236.7

232.8

101.5

(4.6)

11.1

87.2

5.0

9.2

84.8

5.8

10.7

108.0

101.4

101.3

Total utility margin

$

355.8

$

338.1

$

334.1

2017 COMPARED TO 2016. The primary factors contributing 
to changes in the residential and commercial markets were 
increases of $79.8 million in operating revenue and $17.7 
million in utility margin as a result of sales volume increases 
of 131.2 million therms, or 22%, due to customer growth and 
the effects of colder than average weather in 2017 
compared to warmer than average weather in the prior 
period.

2016 COMPARED TO 2015. The primary factors contributing 
to changes in the residential and commercial markets were 
as follows:
• 

sales volumes increased 38.5 million therms, or 7%, 
due to customer growth and comparatively colder 
weather in the first quarter and December of 2016 
compared to record warm weather in 2015;
operating revenues decreased $40.4 million, due to a 
24% decrease in average cost of gas over last year, 

• 

Volumes (therms):

Industrial - firm sales

35.7

33.8

32.4

Industrial - firm
transportation

Industrial - interruptible
sales

Industrial - interruptible
transportation

Total volumes

Utility margin:

Industrial - sales and
transportation

167.7

156.9

144.0

55.1

50.4

57.3

241.4

499.9

234.7

475.8

224.2

457.9

$

31.8

$

31.0

$

30.1

2017 COMPARED TO 2016. Sales and transportation volumes 
increased by 24.1 million therms and utility margin 
increased $0.8 million due to higher usage from colder than 
average weather in 2017 compared to warmer than average 
weather in 2016, and increased usage from higher 
production load.

2016 COMPARED TO 2015. Sales and transportation volumes 
increased by 17.9 million therms and utility margin 
increased $0.9 million due to annual customer service 
election changes, higher fee revenue due to system 
restrictions from cold weather in December 2016, and an 
increase in usage from a few large customers.

Other Revenues
Other revenues include miscellaneous fee income as well 
as regulatory revenue adjustments, which reflect current 
period deferrals to and prior year amortizations from 
regulatory asset and liability accounts, except for gas cost 
deferrals which flow through cost of gas. Decoupling and 
other regulatory amortizations from prior year deferrals are 
included in revenues from residential, commercial, and 

38

industrial firm customers.

Other revenue for 2017, 2016, and 2015 remained flat year-
over-year as expected.

In millions

2017

2016

2015

Other revenues

$

3.9

$

3.8

$

3.9

Cost of Gas
Cost of gas as reported by the utility includes gas 
purchases, gas withdrawn from storage inventory, gains and 
losses from commodity hedges, pipeline demand costs,  
seasonal demand cost balancing adjustments, regulatory 
gas cost deferrals, gas reserves costs, and company gas 
use. The OPUC and WUTC generally require natural gas 
commodity costs to be billed to customers at the actual cost 
incurred, or expected to be incurred, by the utility. Customer 
rates are set each year so that if cost estimates were met 
we would not earn a profit or incur a loss on gas commodity 
purchases; however, in Oregon we have an incentive 
sharing mechanism which has been described under 
"Regulatory Matters—Rate Mechanisms—Purchased Gas 
Adjustment" above. In addition to the PGA incentive sharing 
mechanism, gains and losses from hedge contracts entered 
into after annual PGA rates are effective for Oregon 
customers are also required to be shared and therefore may 
impact net income. Further, we also have a regulatory 
agreement whereby we earn a rate of return on our 
investment in the gas reserves acquired under the original 
agreement with Encana and include gas from our amended 
gas reserves agreement at a fixed rate of $0.4725 per 
therm, which are also reflected in utility margin. See 
"Application of Critical Accounting Policies and Estimates—
Accounting for Derivative Instruments and Hedging 
Activities" below.

Cost of gas highlights include:

Dollars and therms in
millions

2017

2016

2015

Cost of gas

$

325.0

$

260.6

$

327.3

Volumes sold (therms)

831

693

660

Average cost of gas
(cents per therm)

Gain from gas cost
incentive sharing

$

0.39

$

0.38

$

0.50

1.2

4.0

3.2

2017 COMPARED TO 2016. Cost of gas increased $64.4 
million, or 25%, primarily due to the 20% increase in 
volumes sold due to colder than average weather in 2017 
compared to warmer than average weather in 2016, and 
customer growth.

2016 COMPARED TO 2015. Cost of gas decreased $66.7 
million, or 20%, reflecting lower natural gas prices and 
resulting in a $19.4 million credit to customers, partially 
offset by a 5% increase in volume mainly from 
comparatively colder weather in the first quarter and 
December 2016.

The effect on net income from our gas cost incentive 
sharing mechanism resulted in a margin gain of $1.2 million, 
$4.0 million and $3.2 million for 2017, 2016 and 2015, 
respectively, as actual prices were lower than the estimated 

prices included in customer rates due to national warmer 
than average weather, which resulted in lower national 
natural gas commodity prices. For a discussion of our gas 
cost incentive sharing mechanism, see “Regulatory Matters
—Rate Mechanisms—Purchased Gas Adjustment” above.

Business Segments - Gas Storage
Our gas storage segment primarily consists of the non-utility 
portion of our Mist underground storage facility in Oregon 
and our 75% undivided ownership interest in the Gill Ranch 
Facility, an underground storage facility in California. We 
also contract with an independent energy marketing 
company to provide asset management services using our 
utility and non-utility storage and transportation capacity, the 
results of which are included in the gas storage business 
segment. For additional information, see also Note 4.

At Mist, we provide gas storage services to customers in the 
interstate and intrastate markets using storage capacity that 
has been developed in advance of core utility customers’ 
requirements. Pre-tax income from gas storage at Mist and 
asset management services is subject to revenue sharing 
with core utility customers. Under this regulatory incentive 
sharing mechanism, we retain 80% of pre-tax income from 
Mist gas storage services and asset management services 
when the underlying costs of the capacity being used are 
not included in our utility rates, and 33% of pre-tax income 
from such storage and asset management services when 
the capacity being used is included in utility rates. The 
remaining 20% and 67%, respectively, are credited to a 
deferred regulatory account for credit to our core utility 
customers. See "Regulatory Matters—Regulatory 
Proceeding Updates" above for information regarding an 
open docket related to this incentive sharing mechanism.

Our 75% undivided ownership interest in the Gill Ranch 
Facility is held by our wholly-owned subsidiary Gill Ranch, 
LLC, which is also the operator of the facility. Our portion of 
the facility is approximately 15 Bcf of designed gas storage 
capacity. 

Gas storage segment highlights include:

In millions, except EPS data

2017

2016

2015

Operating revenues

Operating expenses

Gas storage net income (loss)
Adjusted gas storage net income(1)

208.7

(116.2)

3.4

16.1

4.3

4.3

$

23.6

$

25.3

$

21.4

EPS - gas storage segment

(4.05)

0.16

16.3

0.2

0.2

0.01

Adjusted EPS - gas storage 
segment(1)
(1)  See the Non-GAAP Reconciliations table at the beginning of Item 
7 for a reconciliation of this non-GAAP measure to its closest 
U.S.GAAP measure.

0.01

0.16

0.12

2017 COMPARED TO 2016. Our gas storage segment net loss 
was $116.2 million, or $4.05 per share, compared to net 
income of $4.3 million, or $0.16 per share, which includes 
the non-cash after-tax impairment of long-lived assets at the 
Gill Ranch Facility of $141.5 million in the fourth quarter of 
2017 and a $21.9 million benefit associated with the TCJA in 
2017. In the fourth quarter, we completed a comprehensive 
strategic review and evaluation process of the Gill Ranch 
Facility that evaluated various alternatives, including a 

39

standards, an increase in use of alternative fuels to meet 
carbon emissions reduction targets, recovery of the 
California economy, growth of domestic industrial 
manufacturing, potential exports of liquefied natural gas 
from the west coast and other favorable storage market 
conditions in and around California. We have not seen the 
rebound in storage prices that we originally anticipated. For 
the last few years, we have worked diligently to operate the 
facility efficiently and have been pursuing various strategic 
alternatives to increase revenues. These efforts included 
working to identify higher-value customers in and/or near 
the northern California market that Gill Ranch serves as well 
as exploring the possibility of providing energy storage 
services such as compressed gas energy storage (CGES). 
In the fourth quarter of 2017, we completed our 
comprehensive strategic review process, which included a 
sale process for the Gill Ranch Facility, and made a 
determination that the Gill Ranch Facility is no longer core to 
our long-term plans.

Additionally, in late 2015, a significant natural gas leak 
occurred at an unaffiliated southern California gas storage 
facility. In response to the incident, both state and federal 
additional regulations were developed. The California 
Department of Oil, Gas and Geothermal Resources 
(DOGGR) developed and proposed new regulations for gas 
storage wells that focus on implementing additional well 
integrity requirements. DOGGR released a new formulation 
of these rules on February 12, 2018.  Although these rules 
are subject to a comment period and possible revision, 
these rules establish a timeframe for completion of 
compliance of seven years, a period much shorter than the 
15 or more years we previously anticipated. In addition, 
PHMSA proposed new federal regulations for underground 
natural gas storage facilities that focus on implementing 
additional pipeline safety requirements of downhole 
facilities, including operations, maintenance and emergency 
response activities regarding wells, wellbore tubing, and 
casing.

While both sets of regulations are still under development, 
and their ultimate impact is unknown, it is likely that the final 
PHMSA and DOGGR regulations will likely result in higher 
costs for all storage providers.  

We will continue to evaluate all strategic options for the 
facility to maximize the value of this asset, and in the 
meantime, we are committed to operating the facility to the 
highest safety standards.

Other
Other primarily consists of our non-utility appliance retail 
center operations, NNG Financial's investment in KB 
Pipeline, an equity investment in TWH, which has invested 
in the Trail West pipeline project, and other miscellaneous 
non-utility investments and business activities. See Note 4 
and Note 12 for further details on other activities and our 
investment in TWH.

potential sale of the asset and we substantially completed 
contracting for the 2018-19 gas year at lower than 
anticipated pricing. These events triggered a requirement 
that management re-evaluate the carrying value of the Gill 
Ranch Facility. That analysis resulted in the non-cash 
impairment.

Excluding these items, adjusted gas storage net income 
decreased $0.9 million, or $0.04 per share, primarily due to 
a decrease in gas storage revenues largely due to lower 
asset management revenues from our Mist facility and 
transportation capacity. See the Non-GAAP reconciliations 
at the beginning of Item 7 for additional information.

2016 COMPARED TO 2015. Our gas storage segment net 
income increased $4.1 million, or $0.15 per share, primarily 
due to the following factors:
• 

a $3.9 million increase in operating revenue primarily 
from higher asset management revenues from our Mist 
facility and transportation capacity, and slightly higher 
firm contract prices at the Gill Ranch Facility for the 
2016-17 gas year; and 
a $2.8 million decrease in interest expense from the 
early retirement of $20 million of Gill Ranch debt in 
December 2015.

• 

We have completed contracting for the 2017-18 gas year for 
our Mist facility, which remains under long-term contracts at 
similar prices to prior periods. Our Mist facility benefits from 
limited competition from other Pacific Northwest storage 
facilities primarily because of its geographic location.

The gas storage market dynamics at the Gill Ranch Facility 
differ from our Mist facility. Over the past few years, market 
prices for natural gas storage, particularly in California, were 
negatively affected by the abundant supply of natural gas, 
low volatility of natural gas prices, and surplus gas storage 
capacity. 

In 2007, NW Natural's subsidiary Gill Ranch Storage, LLC 
jointly with Pacific Gas and Electric (PG&E) made an 
investment decision to build the Gill Ranch Facility, a gas 
storage facility in California. At that time, our market analysis 
projected that natural gas storage would be critical in 
achieving California's renewable portfolio standards and 
supporting the region's drive to a lower carbon energy 
landscape. Construction was completed and operations 
began at the Gill Ranch Facility in 2010 under multi-year 
storage agreements with terms that ended as the full market 
implications from the shale gas revolution were transforming 
the natural gas industry. The additional shale gas eliminated 
the resource constraints that were expected to exist over the 
long term and resulted in lower gas prices, decreased 
seasonal price spreads and volatility, and consequently, 
reduced the value of gas storage to customers. As a result, 
over the last few years, we have contracted the Gill Ranch 
Facility under short-term agreements to allow us to take 
advantage of any rebound in storage prices or other 
strategies that would increase revenues.

We have believed and continue to believe that we may see 
storage price improvement or an increase in the demand for 
natural gas storage in California in the future driven by a 
number of factors, including changes in the electric 
generation triggered by California’s renewable portfolio 

40

Consolidated Operations

Operations and Maintenance
Operations and maintenance highlights include:

In millions

2017

2016

2015

Operations and maintenance

$ 165.2

$ 150.0

$ 157.5

2017 COMPARED TO 2016. Operations and maintenance 
expense increased $15.3 million, primarily due to the 
following factors:
• 

a $6.4 million increase in utility payroll and benefits due 
to increased headcount and general salary increases; 
and
a $1.0 million increase in safety equipment upgrade 
costs.

• 

2016 COMPARED TO 2015. Operations and maintenance 
expense decreased $7.5 million, primarily due to the 
following factors:
• 

the $15.0 million pre-tax charge for the regulatory 
disallowance associated with the February 2015 OPUC 
Order on the recovery of past environmental cost 
deferrals recorded in 2015. We also expensed an 
additional $1.0 million related to the 2015 Order; 
partially offset by
a $6.5 million increase in non-payroll costs, which 
returned to a more sustainable level in 2016 after 
temporary cost savings initiatives in the prior year. Non-
payroll increases were primarily related to higher 
professional service and contract work costs due to 
general customer service cost increases from system 
integrity work, and other maintenance; and
a $1.2 million increase in payroll and benefits due to 
increased headcount and general pay increases.

• 

• 

Depreciation and Amortization
Depreciation and amortization highlights include:

In millions

2017

2016

2015

Depreciation and amortization

$

85.6

$

82.3

$

80.9

2017 COMPARED TO 2016. Depreciation and amortization 
expense increased by $3.3 million due to utility plant 
additions that included investments in our natural gas 
transmission and distribution system, facility upgrades, and 
enhanced technology.

2016 COMPARED TO 2015. Depreciation and amortization 
expense increased by $1.4 million due to utility plant 
additions that included investments in our natural gas 
transmission and distribution system, storage facilities, and 
technology.

Other Income (Expense), Net
Other income (expense), net highlights include:

In millions

2017

2016

2015

Equity portion of AFUDC

$

2.7

$

— $

Gains from company-
owned life insurance

Interest income

Loss from equity
investments

Net interest income
(expense) on deferred
regulatory accounts

Other non-operating

Total other income
(expense), net

2.5

0.2

1.7

0.1

—

2.2

0.1

(0.1)

(0.1)

(0.1)

2.0

(2.0)

(0.1)

(2.1)

8.2

(2.7)

$

5.3

$

(0.5) $

7.7

Delinquent customer receivable balances continue to 
remain at historically low levels. The utility's bad debt 
expense as a percent of revenues was 0.1% for 2017, 2016, 
and 2015.

In addition to fluctuations in operations and maintenance 
expense reported above, we have OPUC approval to defer 
certain utility pension costs in excess of what is currently 
recovered in customer rates. This pension cost deferral is 
recorded to a regulatory balancing account, which stabilizes 
the amount of operations and maintenance expense each 
year. Pension cost deferrals, excluding interest, were $6.5 
million, $6.3 million, and $8.2 million for the years ended 
December 31, 2017, 2016 and 2015, respectively. As a 
result, increased pension costs had a minimal effect on 
operations and maintenance expense in 2017, 2016, and 
2015, with the increase principally related to the costs 
allocated to our Washington operations, which are not 
covered by the pension balancing account. For further 
explanation of the pension balancing account, see Note 8 
and “Regulatory Matters—Rate Mechanisms—Pension Cost 
Deferral and Prepaid Pension Assets,” above.

2017 COMPARED TO 2016. Other income (expense), net, 
increased $5.9 million primarily due to the January 2016 
Order from the OPUC, which resulted in a pre-tax $2.8 
million interest disallowance in 2016, an increase of $2.7 
million in the equity portion of AFUDC, and $0.8 million of 
gains from company-owned life insurance.

2016 COMPARED TO 2015. Other income (expense), net, 
increased $8.3 million primarily due to the recognition of 
$5.3 million of the equity component in interest income from 
our deferred environmental expenses in the prior year, 
which did not recur in 2016. We recognized the equity 
earnings of these deferred regulatory asset balances as a 
result of the OPUC SRRM Order we received in February 
2015. In addition, a January 2016 Order from the OPUC 
resulted in a write-off of $2.8 million of interest during 2016.

Interest Expense, Net 
Interest expense, net highlights include:

In millions

2017

2016

2015

Interest expense, net

$

38.5

$

39.1

$

42.5

2017 COMPARED TO 2016. Interest expense, net decreased 
$0.6 million primarily due to a $2.1 million increase in the 
interest-related portion of AFUDC, partially offset by 
increased interest expense of $1.5 million due to the 

41

issuance of long-term debt in December 2016 and August 
2017. 

Our consolidated capital structure was as follows:

2016 COMPARED TO 2015.  Interest expense, net of amounts 
capitalized, decreased $3.4 million primarily due to the 
redemption of $40 million of utility First Mortgage Bonds 
(FMBs) in June 2015 and the early retirement of $20 million 
of Gill Ranch's debt in December 2015, which included a 
make whole interest provision.

Income Tax Expense
Income tax expense highlights include:

In millions

2017

2016

2015

Income tax (benefit) expense

$ (30.8)

$ 40.7

$ 35.8

Effects of non-GAAP 
adjustments(1)
Effects from the TCJA(1)

51.0

21.4

1.3

—

5.9

—

Adjusted income tax expense

$ 41.6

$ 42.0

$ 41.7

Effective tax rate

35.6%

40.9%

40.0%

Adjusted effective tax rate

39.2%

40.8%

39.9%

(1) See the Non-GAAP Reconciliations table at the beginning of Item 
7 for a reconciliation of this non-GAAP measure to its closest 
U.S.GAAP measure.

2017 COMPARED TO 2016. Our effective tax rate decreased 
by 5.3%. Excluding the tax benefits associated with the 
impairment of long-lived assets at the Gill Ranch Facility 
and the TCJA enactment in 2017 of $51.0 million and $21.4 
million, respectively, and the $1.3 million tax effects of non-
GAAP adjustments in 2016, our adjusted effective tax rate 
decreased 1.6%. See the Non-GAAP reconciliations at the 
beginning of Item 7 for additional information. The adjusted 
effective tax rate decreased primarily as a result of AFUDC 
equity income and increased stock-based compensation 
deductions in 2017. 

2016 COMPARED TO 2015. The increase in the effective 
income tax rate is due to lower benefits of depletion 
deductions from our gas reserves activity.

FINANCIAL CONDITION

Capital Structure
One of our long-term goals is to maintain a strong 
consolidated capital structure with a long-term target utility 
capital structure of 50% common stock and 50% long-term 
debt. When additional capital is required, debt or equity 
securities are issued depending on both the target capital 
structure and market conditions. These sources of capital 
are also used to fund long-term debt retirements and short-
term commercial paper maturities. See "Liquidity and 
Capital Resources" below and Note 7. 

Achieving the target capital structure and maintaining 
sufficient liquidity to meet operating requirements are 
necessary to maintain attractive credit ratings and provide 
access to capital markets at reasonable costs. 

Common stock equity

Long-term debt

Short-term debt, including current
maturities of long-term debt

Total

December 31,

2017

2016

47.1%

43.3

52.4%

41.9

9.6

5.7

100.0%

100.0%

During 2017, changes to our capital structure were primarily 
due to issuances of long-term debt instruments and the 
impairment of long-lived assets at the Gill Ranch Facility. 
The net proceeds from the debt issuances will be used for 
general corporate purposes, primarily to fund our ongoing 
utility construction programs.  See further discussion below 
in "Cash Flows — Financing Activities".

Liquidity and Capital Resources 
At both December 31, 2017 and December 31, 2016, we 
had approximately $3.5 million of cash and cash 
equivalents. In order to maintain sufficient liquidity during 
periods when capital markets are volatile, we may elect to 
maintain higher cash balances and add short-term 
borrowing capacity. In addition, we may also pre-fund utility 
capital expenditures when long-term fixed rate environments 
are attractive. As a regulated entity, our issuance of equity 
securities and most forms of debt securities are subject to 
approval by the OPUC and WUTC. Our use of retained 
earnings is not subject to those same restrictions.

Utility Segment  
For the utility segment, the short-term borrowing 
requirements typically peak during colder winter months 
when the utility borrows money to cover the lag between 
natural gas purchases and bill collections from customers. 
Our short-term liquidity for the utility is primarily provided by 
cash balances, internal cash flow from operations, proceeds 
from the sale of commercial paper notes, as well as 
available cash from multi-year credit facilities, short-term 
credit facilities, company-owned life insurance policies, the 
sale of long-term debt, and issuances of equity. Utility long-
term debt and equity issuance proceeds are primarily used 
to finance utility capital expenditures, refinance maturing 
debt of the utility, and provide temporary funding for other 
general corporate purposes of the utility. 

Based on our current debt ratings (see "Credit Ratings" 
below), we have been able to issue commercial paper and 
long-term debt at attractive rates and have not needed to 
borrow or issue letters of credit from our back-up credit 
facility. In the event we are not able to issue new debt due to 
adverse market conditions or other reasons, we expect our 
near-term liquidity needs can be met using internal cash 
flows or, for the utility segment, drawing upon our committed 
credit facility. We also have a universal shelf registration 
statement filed with the SEC for the issuance of secured 
and unsecured debt or equity securities, subject to market 
conditions and certain regulatory approvals. As of December 
31, 2017, we have Board authorization to issue up to $75 
million of additional FMBs. We also have OPUC approval to 
issue up to $75 million of additional long-term debt for 
approved purposes.

42

  
Our issuance of FMBs, which includes our medium-term 
notes, under our mortgage and deed of trust is limited by 
eligible properties, satisfaction of an adjusted net earnings 
test, and other provisions of the mortgage. The non-cash 
impairment of long-lived assets at the Gill Ranch Facility is 
expected to result in our inability to satisfy the earnings test 
throughout most of 2018. However, we are permitted to 
issue FMBs without meeting the earnings test on the basis 
of the $97.0 million of FMBs which will mature in 2018, an 
amount that is sufficient to accommodate our expected 
issuances of FMBs in 2018. There is no similar restriction on 
our ability to issue unsecured long-term debt.

In the event our senior unsecured long-term debt ratings are 
downgraded, or our outstanding derivative position exceeds 
a certain credit threshold, our counterparties under 
derivative contracts could require us to post cash, a letter of 
credit, or other forms of collateral, which could expose us to 
additional cash requirements and may trigger increases in 
short-term borrowings while we were in a net loss position. 
We were not required to post collateral at December 31, 
2017. However, if the credit risk-related contingent features 
underlying these contracts were triggered on December 31, 
2017, assuming our long-term debt ratings dropped to non-
investment grade levels, we could have been required to 
post $15.4 million in collateral with our counterparties. See 
"Credit Ratings" below and Note 13. 

Other items that may have a significant impact on our 
liquidity and capital resources include pension contribution 
requirements and environmental expenditures. 

PENSION CONTRIBUTION. We expect to make significant 
contributions to our company-sponsored defined benefit 
plan, which is closed to new employees, over the next 
several years until we are fully funded under the Pension 
Protection Act rules, including the new rules issued under 
the Moving Ahead for Progress in the 21st Century Act 
(MAP-21) and the Highway and Transportation Funding Act 
of 2014 (HATFA). See "Application of Critical Accounting 
Policies—Accounting for Pensions and Postretirement 
Benefits" below. 

BONUS DEPRECIATION. Regarding income tax, 50 percent 
bonus depreciation was available for a large portion of our 
capital expenditures in 2015, 2016 and most of 2017 for 
both federal and Oregon. This reduced taxable income and 
provided cash flow benefits. However, due to the enactment 
of TCJA on December 22, 2017, bonus depreciation is 
eliminated for property acquired after September 27, 2017. 
Accordingly, we do not anticipate similar cash flow benefits 
related to bonus depreciation in the future.

ENVIRONMENTAL EXPENDITURES. Concerning 
environmental expenditures, we expect to continue using 
cash resources to fund our environmental liabilities. In 2015, 
we received an Order from the OPUC regarding our SRRM 
and began recovering amounts through utility rates in 
November 2015. In addition, the OPUC issued a 
subsequent Order regarding SRRM implementation in 
January 2016. See Note 15, and "Results of Operations—
Regulatory Matters—Environmental Costs" above.

GAS STORAGE. Short-term liquidity for the gas storage 
segment is supported by cash balances, internal cash flow 

43

from operations, equity contributions from its parent 
company, and, if necessary, additional external financing. 

The amount and timing of the Gill Ranch Facility's cash 
flows from year to year are uncertain, as the majority of 
current storage contracts are short-term. In the fourth 
quarter of 2017, we recognized a non-cash pretax 
impairment of long-lived assets at the Gill Ranch Facility of 
$192.5 million, which is included in our gas storage 
segment. As a result of the impairment considerations, 
estimated cash flows from the Gill Ranch Facility were re-
evaluated, and although determined no longer sufficient to 
cover the carrying value of the assets, we do not anticipate 
material changes in our ability to access sources of cash for 
short-term liquidity.

CONSOLIDATED LIQUIDITY. Based on several factors, 
including our current credit ratings, our commercial paper 
program, current cash reserves, committed credit facilities, 
and our expected ability to issue long-term debt in the 
capital markets, we believe our liquidity is sufficient to meet 
anticipated near-term cash requirements, including all 
contractual obligations, investing, and financing activities as 
discussed in Contractual Obligations and Cash Flows below.

DIVIDEND POLICY. We have paid quarterly dividends on our 
common stock each year since stock was first issued to the 
public in 1951. Annual common stock dividend payments 
per share, adjusted for stock splits, have increased each 
year since 1956. The declarations and amount of future 
dividends will depend upon our earnings, cash flows, 
financial condition and other factors. The amount and timing 
of dividends payable on our common stock is at the sole 
discretion of our Board of Directors.

OFF-BALANCE SHEET ARRANGEMENTS. Except for certain 
lease and purchase commitments, we have no material off-
balance sheet financing arrangements. See "Contractual 
Obligations" below.

In October 2017, we entered into a 20-year operating lease 
agreement for our new headquarters location in Portland, 
Oregon. Our existing headquarters lease expires in 2020 
and after an extensive search and evaluation process with a 
focus on seismic preparedness, safety, reliability, least cost 
to our customers and a continued commitment to our 
employees and the communities we serve, we executed a 
new lease for suitable commercial office space in Portland, 
Oregon. Payments under the lease are expected to 
commence in 2020 and total estimated base rent payments 
over the life of the lease are approximately $160 million. We 
have the option to extend the term of the lease for two 
additional seven-year periods.

Additionally, the lease was analyzed in consideration of  
build-to-suit lease accounting guidance, and we concluded 
that we are the accounting owner of the asset during 
construction. As a result, we recognized $0.5 million in 
Property, plant and equipment and an obligation in Other 
non-current liabilities for the same amount on our 
consolidated balance sheet at December 31, 2017. In 2018, 
we expect to recognize an additional $27.0 million 
associated with the build-to-suit accounting treatment of this 
lease. These accounting transactions are non-cash in 
nature, and as such, are not included in our cash flow 

analysis and capital expenditures forecasts below, and have 
no impact on our short-term liquidity. In 2019, pursuant to 
the new lease standard issued by the FASB, we expect to 

de-recognize the associated build-to-suit asset and liability 
as we will not be subject to build-to-suit accounting under 
the new lease standard.

Contractual Obligations
The following table shows our contractual obligations at December 31, 2017 by maturity and type of obligation:

Payments Due in Years Ending December 31,

In millions

2018

2019

2020

2021

2022

Thereafter

Total

Short-term debt maturities

$

54.2

$

— $

— $

— $

— $

— $

Long-term debt maturities

Interest on long-term debt
Postretirement benefit payments(1)

Operating leases
Gas purchases(2)

Gas pipeline capacity commitments
Other purchase commitments(3)
Other long-term liabilities(4)

97.0

36.4

25.1

5.4

63.9

83.5

12.9

17.3

30.0

34.7

26.0

5.4

2.7

82.1

0.9

—

75.0

28.9

27.0

6.9

2.7

77.0

0.6

—

60.0

27.8

28.0

7.5

2.3

65.6

0.1

—

—

26.1

28.6

7.6

—

60.1

—

—

524.7

249.9

161.0

169.4

—

601.8

—

—

54.2

786.7

403.8

295.7

202.2

71.6

970.1

14.5

17.3

Total

$

395.7

$

181.8

$

218.1

$

191.3

$

122.4

$

1,706.8

$

2,816.1

(1)  Postretirement benefit payments primarily consists of two items: (1) estimated pension and other postretirement plan payments, which are 
funded by plan assets and future cash contributions, and (2) required payments to the Western States multiemployer pension plan due to 
our withdrawal from the plan in December 2013. See Note 8.

(2)  Gas purchases include contracts which use price formulas tied to monthly index prices. The commitment amounts presented incorporate 

the December 2017 first of month index price for each supply basin from which gas is purchased. For a summary of gas purchase and gas 
pipeline capacity commitments, see Note 14.

(3)  Other purchase commitments primarily consist of base gas requirements and remaining balances under existing purchase orders. 
(4)  Other long-term liabilities includes accrued vacation liabilities for management employees and deferred compensation plan liabilities for 
executives and directors. The timing of these payments are uncertain; however, these payments are unlikely to all occur in the next 12 
months.

In addition to known contractual obligations listed in the 
above table, we have also recognized liabilities for future 
environmental remediation or action. The exact timing of 
payments beyond 12 months with respect to those liabilities 
cannot be reasonably estimated due to numerous 
uncertainties surrounding the course of environmental 
remediation and the preliminary nature of site investigations. 
See Note 15 for a further discussion of environmental 
remediation cost liabilities.

finance gas purchases and accounts receivable, short-term 
debt may also be used to temporarily fund utility capital 
requirements. Commercial paper and bank loans are 
periodically refinanced through the sale of long-term debt or 
equity securities. When we have outstanding commercial 
paper, which is sold through two commercial banks under 
an issuing and paying agency agreement, it is supported by 
one or more unsecured revolving credit facilities. See 
“Credit Agreements” below. 

At December 31, 2017, 629 of our utility employees were 
members of the Office and Professional Employees 
International Union (OPEIU) Local No. 11. In May 2014, our 
union employees ratified a new labor agreement (Joint 
Accord) that expires on November 30, 2019, and thereafter 
from year to year unless either party serves notice of its 
intent to negotiate modifications to the collective bargaining 
agreement. The remaining terms of Joint Accord include the 
following items: a scheduled 3% wage increase effective 
December 1 each year with the potential for up to an 
additional 3% per year based on wage inflation at or above 
4%. The Joint Accord also maintains competitive health 
benefits, including a 15% to 20% premium cost sharing by 
employees, a 401(k) contribution of 4% for employees hired 
after our pension plan was closed on December 31, 2009, 
and a 401(k) match of 50% of the first 6% of savings, and 
other flexibility provisions benefiting the Company. 

At December 31, 2017 and 2016, our utility had short-term 
debt outstanding of $54.2 million and $53.3 million, 
respectively.  The effective interest rate on short-term debt 
outstanding at December 31, 2017 and 2016 was 1.9% and 
0.8%, respectively. 

Credit Agreements
We have a $300 million credit agreement, with a feature that 
allows us to request increases in the total commitment 
amount, up to a maximum of $450 million. The maturity date 
of the agreement is December 20, 2019. 

All lenders under the agreement are major financial 
institutions with committed balances and investment grade 
credit ratings as of December 31, 2017 as follows:

In millions

Lender rating, by category

Loan Commitment

Short-Term Debt
Our primary source of utility short-term liquidity is from the 
sale of commercial paper and bank loans. In addition to 
issuing commercial paper or bank loans to meet working 
capital requirements, including seasonal requirements to 

AA/Aa

A/A1

Total

44

$

$

201,000

99,000

300,000

 
 
 
 
Based on credit market conditions, it is possible one or more 
lending commitments could be unavailable to us if the 
lender defaulted due to lack of funds or insolvency; 
however, we do not believe this risk to be imminent due to 
the lenders' strong investment-grade credit ratings.

Our credit agreement permits the issuance of letters of 
credit in an aggregate amount of up to $100 million. The 
principal amount of borrowings under the credit agreement 
is due and payable on the maturity date. There were no 
outstanding balances under this credit agreement at 
December 31, 2017 or 2016. The credit agreement requires 
us to maintain a consolidated indebtedness to total 
capitalization ratio of 70% or less. Failure to comply with this 
covenant would entitle the lenders to terminate their lending 
commitments and accelerate the maturity of all amounts 
outstanding. We were in compliance with this covenant at 
December 31, 2017 and 2016, with consolidated 
indebtedness to total capitalization ratios of 52.9% and 
47.6%, respectively.

The agreement also requires us to maintain credit ratings 
with Standard & Poor's (S&P) and Moody's Investors 
Service, Inc. (Moody’s) and notify the lenders of any change 
in our senior unsecured debt ratings or senior secured debt 
ratings, as applicable, by such rating agencies. A change in 
our debt ratings by S&P or Moody’s is not an event of 
default, nor is the maintenance of a specific minimum level 
of debt rating a condition of drawing upon the credit 
agreement. Rather, interest rates on any loans outstanding 
under the credit agreements are tied to debt ratings and 
therefore, a change in the debt rating would increase or 
decrease the cost of any loans under the credit agreements 
when ratings are changed. See "Credit Ratings" below.

Credit Ratings
Our credit ratings are a factor of our liquidity, potentially 
affecting our access to the capital markets including the 
commercial paper market. Our credit ratings also have an 
impact on the cost of funds and the need to post collateral 
under derivative contracts. The following table summarizes 
our current debt ratings:

Commercial paper (short-term debt)

Senior secured (long-term debt)

Senior unsecured (long-term debt)

Corporate credit rating

Ratings outlook

S&P

Moody's

A-1

AA-

n/a

A+

P-2

A1

A3

n/a

Stable

Negative

• 

• 

• 

In January 2018, Moody's revised our ratings outlook from 
"stable" to "negative". This revision was a result of their view 
of the potential negative impact that TCJA could have on our 
regulated utility cash flow metrics. We expect the elimination 
of bonus depreciation on regulated utilities will increase 
cash taxes in the near term. However, we expect to see a 
net increase in cash flows as a result of TCJA over the 
longer term as taxes are a pass through to customers and 
lower deferred tax liabilities and no bonus depreciation are 
expected to increase regulatory returns.

The above credit ratings and ratings outlook are dependent 
upon a number of factors, both qualitative and quantitative, 

and are subject to change at any time. The disclosure of or 
reference to these credit ratings is not a recommendation to 
buy, sell or hold NW Natural securities. Each rating should 
be evaluated independently of any other rating.

Long-Term Debt
The following debentures were retired:

In millions

Utility First Mortgage Bonds

Years Ended December 31,

2017

2016

2015

4.70% Series B due 2015

$

— $

— $

5.15% Series B due 2016

7.00% Series B due 2017

Subsidiary Debt

Fixed-rate

Cash Flows

—

40

40

$

25

—

25

$

— $

— $

40

$

25

$

$

$

$

40

—

—

40

20

60

Operating Activities
Changes in our operating cash flows are primarily affected 
by net income or loss, changes in working capital 
requirements, and other cash and non-cash adjustments to 
operating results. 

Operating activity highlights include:

In millions

2017

2016

2015

Cash provided by operating
activities

$ 206.7

$ 222.1

$ 184.7

2017 COMPARED TO 2016. The significant factors 
contributing to the $15.4 million decrease in cash flows 
provided by operating activities were as follows:
• 

a decrease of $21.9 million due to $14.8 million income 
taxes paid in 2017 compared to a refund of $7.2 million 
in 2016 as a result of the enactment of bonus 
depreciation in December 2015; 
a decrease of $5.0 million due to an increase in 
contributions paid to qualified defined benefit pension 
plans; and 
a net decrease of $11.4 million from changes in working 
capital related to receivables, inventories, and accounts 
payable reflecting colder than average weather in 2017 
compared to the prior period; partially offset by
an increase of $27.3 million in cash flow benefits from 
changes in deferred gas cost balances primarily due to 
the $19.4 million gas cost savings credited to 
customers in 2016 that did not occur in 2017.

2016 COMPARED TO 2015. The significant factors 
contributing to the $37.5 million increase in operating cash 
flows provided by operating activities were as follows:
• 

a net increase of $29.4 million from changes in working 
capital related to cold weather in December 2016 and 
its impact on receivables, inventories, and accounts 
payable; and
an increase of $27.6 million in tax related accounts 
primarily due to a federal tax refund and an increase in 
accrued taxes and net deferred tax liabilities primarily 

• 

45

 
 
 
 
 
 
 
• 

• 

• 

due to the enactment of bonus depreciation;
an increase of $17.7 million from increased cash 
collections from our decoupling mechanism;
an increase of $9.8 million from collections under the 
SRRM; partially offset by 
a decrease of $42.1 million from changes in deferred 
gas cost balances due to lower natural gas prices than 
those embedded in the PGA, which also resulted in a 
$19.4 million early credit to customers’ bills in June 
2016.

During the year ended December 31, 2017, we contributed 
$19.4 million to our utility's qualified defined benefit pension 
plan, compared to $14.5 million for 2016 and $14.1 million 
for 2015. The amount and timing of future contributions will 
depend on market interest rates and investment returns on 
the plans’ assets. See Note 8.

Bonus depreciation of 50% has been available for federal 
and Oregon purposes in 2015, 2016 and most of 2017. This 
reduced taxable income and provided cash flow benefits. 
Bonus depreciation for 2015 was not enacted until 
December 18, 2015, and was extended retroactively back to 
January 1, 2015 of the respective year. As a result, 
estimated income tax payments were made throughout 
2015 without the benefit of bonus depreciation for the year. 
This delayed the cash flow benefit of bonus depreciation 
until refunds could be requested and received. We received 
refunds of federal income tax overpayments of $7.9 million 
and $2.0 million in during 2016 and 2015, respectively. As a 
result of TCJA, bonus depreciation was eliminated for 
property acquired after September 27, 2017. Accordingly, 
we do not anticipate similar cash flow benefits related to 
bonus depreciation in the future.

We have lease and purchase commitments relating to our 
operating activities that are financed with cash flows from 
operations. For information on cash flow requirements 
related to leases and other purchase commitments, see 
“Financial Condition—Contractual Obligations” above and 
Note 14.

Investing Activities
Investing activity highlights include:

In millions

2017

2016

2015

Total cash used in investing
activities

$ (214.2) $ (136.6) $ (115.3)

Capital expenditures

(213.6)

(139.5)

(118.3)

2017 COMPARED TO 2016. The $77.6 million increase in cash 
used in investing activities was primarily due to higher 
capital expenditures primarily related to our North Mist Gas 
Storage Expansion Project as well as customer growth, 
system reinforcement, technology, and facilities. 

2016 COMPARED TO 2015. The $21.3 million increase in cash 
used in investing activities was primarily due to higher utility 
capital expenditures related to improvements at our Newport 
LNG facility in Oregon, additional infrastructure investments 
in Clark County, Washington, and capital expenditures for 
our North Mist gas storage expansion project.

For the five-year period 2018 to 2022, capital expenditures 

are estimated to be between $750 and $850 million. This 
includes investments ranging from $650 to $700 million for 
core utility capital expenditures that will support continued 
customer growth, distribution system maintenance and 
improvements, technology investments, and utility gas 
storage facility maintenance. In addition, the five-year period 
range includes $20 to $30 million of additional investments 
to complete the North Mist gas storage expansion in 2018, 
and investments of $60 to $70 million related to planned 
upgrades and refurbishments to utility storage facilities and 
resource centers. Most of the required funds for these 
investments are expected to be internally generated over 
the five-year period, with short-term and long-term debt and 
equity providing liquidity.

Included in the five year period, 2018 utility capital 
expenditures are estimated to be between $190 and $220 
million, including $20 to $30 million to complete the 
construction of our North Mist gas storage facility expansion. 
We expect to invest less than $5 million in non-utility capital 
expenditures for gas storage and other activities during 
2018. Additional spend for gas storage and other 
investments during and after 2018 are expected to be paid 
from working capital and additional equity contributions from 
NW Natural as needed.

Financing Activities
Financing activity highlights include:

In millions

2017

2016

2015

Total cash provided by (used
in) financing activities

$

Change in short-term debt

Change in long-term debt

Change in common stock
issued, net

7.4

0.9

60.0

$

(86.2) $

(74.7)

(216.7)

125.0

35.3

(60.0)

—

52.8

—

2017 COMPARED TO 2016. The $93.6 million increase in cash 
provided by financing activities was primarily due to $217.6 
million lower repayments of short-term debt compared to the 
prior period, partially offset by $65.0 million lower net 
proceeds from long-term debt activity in 2017 and $52.8 
million of common stock proceeds in 2016.

2016 COMPARED TO 2015. The $11.5 million increase in cash 
used in financing activities was primarily due to higher 
repayments of short term loans and commercial paper of 
$252 million, partially offset by proceeds from $150 million 
of long-term debt issued in December 2016 and $53 million 
of common stock issued in November 2016, along with a 
$35 million decrease in repayments of long-term debt as 
compared to 2015.

Pension Cost and Funding Status of Qualified 
Retirement Plans
Pension costs are determined in accordance with 
accounting standards for compensation and retirement 
benefits. See “Application of Critical Accounting Policies and 
Estimates – Accounting for Pensions and Postretirement 
Benefits” below. Pension expense for our qualified defined 
benefit plan, which is allocated between operations and 
maintenance expenses, capital expenditures, and the 
deferred regulatory balancing account, totaled $18.1 million 
in 2017, an increase of $0.8 million from 2016. The fair 

46

market value of pension assets in this plan increased to 
$287.9 million at December 31, 2017 from $257.7 million at 
December 31, 2016. The increase was due to a return on 
plan assets of $40.3 million and $19.4 million in employer 
contributions, offset by benefit payments of $29.5 million.

•  derivative instruments and hedging activities;
•  pensions and postretirement benefits;
•  income taxes;
•  environmental contingencies; and
•  impairment of long-lived assets.

We make contributions to the company-sponsored qualified 
defined benefit pension plan based on actuarial 
assumptions and estimates, tax regulations, and funding 
requirements under federal law. Our qualified defined 
benefit pension plan was underfunded by $161.7 million at 
December 31, 2017. We plan to make contributions during 
2018 of $15.5 million. See Note 8 for further pension 
disclosures.

Ratios of Earnings to Fixed Charges
For the year ended December 31, 2017, our earnings were 
insufficient to cover our fixed charges by $86.4 million as a 
result of the non-cash impairment of long-lived assets at the 
Gill Ranch Facility. For the years ended December 31, 2016 
and 2015, our ratios of earnings to fixed charges, computed 
using the method outlined by the SEC, were 3.39 and 3.00, 
respectively. For this purpose, earnings consist of net 
income before income taxes plus fixed charges, and fixed 
charges consist of interest on all indebtedness, the 
amortization of debt expense and discount or premium, and 
the estimated interest portion of rentals charged to income 
or loss. See Exhibit 12 for the detailed ratio calculation.

Contingent Liabilities
Loss contingencies are recorded as liabilities when it is 
probable that a liability has been incurred and the amount of 
the loss is reasonably estimable in accordance with 
accounting standards for contingencies. See “Application of 
Critical Accounting Policies and Estimates” below. At 
December 31, 2017, our total estimated liability related to 
environmental sites is $127.4 million. See Note 15 and 
"Results of Operations—Regulatory Matters—Rate 
Mechanisms—Environmental Costs" above.

New Accounting Pronouncements 
For a description of recent accounting pronouncements that 
may have an impact on our financial condition, results of 
operations, or cash flows, see Note 2.

APPLICATION OF CRITICAL ACCOUNTING POLICIES 
AND ESTIMATES

In preparing our financial statements in accordance with 
GAAP, management exercises judgment in the selection 
and application of accounting principles, including making 
estimates and assumptions that affect reported amounts of 
assets, liabilities, revenues, expenses, and related 
disclosures in the financial statements. Management 
considers our critical accounting policies to be those which 
are most important to the representation of our financial 
condition and results of operations and which require 
management’s most difficult and subjective or complex 
judgments, including accounting estimates that could result 
in materially different amounts if we reported under different 
conditions or used different assumptions. Our most critical 
estimates and judgments include accounting for:
•  regulatory accounting;
•  revenue recognition;

47

Management has discussed its current estimates and 
judgments used in the application of critical accounting 
policies with the Audit Committee of the Board. Within the 
context of our critical accounting policies and estimates, 
management is not aware of any reasonably likely events or 
circumstances that would result in materially different 
amounts being reported. For a description of recent 
accounting pronouncements that could have an impact on 
our financial condition, results of operations, or cash flows, 
see Note 2.

Regulatory Accounting
Our utility is regulated by the OPUC and WUTC, which 
establish the rates and rules governing utility services 
provided to customers, and, to a certain extent, set forth 
special accounting treatment for certain regulatory 
transactions. In general, we use the same accounting 
principles as non-regulated companies reporting under 
GAAP. However, authoritative guidance for regulated 
operations (regulatory accounting) requires different 
accounting treatment for regulated companies to show the 
effects of such regulation. For example, we account for the 
cost of gas using a PGA deferral and cost recovery 
mechanism, which is submitted for approval annually to the 
OPUC and WUTC. See "Results of Operations—Regulatory 
Matters—Rate Mechanisms—Purchased Gas Adjustment" 
above. There are other expenses and revenues that the 
OPUC or WUTC may require us to defer for recovery or 
refund in future periods. Regulatory accounting requires us 
to account for these types of deferred expenses (or deferred 
revenues) as regulatory assets (or regulatory liabilities) on 
the balance sheet. When we are allowed to recover these 
regulatory assets from, or refund regulatory liabilities to, 
customers, we recognize the expense or revenue on the 
income statement at the same time we realize the 
adjustment to amounts included in utility rates charged to 
customers.

The conditions we must satisfy to adopt the accounting policies 
and practices of regulatory accounting include:
an independent regulator sets rates;
• 
the regulator sets the rates to cover specific costs of 
• 
delivering service; and
the service territory lacks competitive pressures to reduce 
rates below the rates set by the regulator. 

• 

Because our utility satisfies all three conditions, we continue 
to apply regulatory accounting to our utility operations. 
Future accounting changes, regulatory changes, or changes 
in the competitive environment could require us to 
discontinue the application of regulatory accounting for 
some or all of our regulated businesses. This would require 
the write-off of those regulatory assets and liabilities that 
would no longer be probable of recovery from or refund to 
customers. 

Based on current accounting and regulatory competitive 
conditions, we believe it is reasonable to expect continued 

  
 
application of regulatory accounting for our utility activities. 
Further, it is reasonable to expect the recovery or refund of 
our regulatory assets and liabilities at December 31, 2017 
through future customer rates. If we should determine all or 
a portion of these regulatory assets or liabilities no longer 
meet the criteria for continued application of regulatory 
accounting, then we would be required to write-off the net 
unrecoverable balances against earnings in the period such 
determination is made. The net balance in regulatory asset 
and liability accounts was a net liability of $217.7 million and 
a net asset of $10.3 million as of December 31, 2017 and 
2016, respectively. See Note 2 for more detail on our 
regulatory balances.

Revenue Recognition 
Utility and non-utility revenues, which are derived primarily 
from the sale, transportation, and storage of natural gas, are 
recognized upon the delivery of gas commodity or services 
rendered to customers. 

Accrued Unbilled Revenue 
For a description of our policy regarding accrued unbilled 
revenue for both the utility and non-utility revenues, see 
Note 2. The following table presents changes in key metrics 
if the estimated percentage of unbilled volume at December 
31 was adjusted up or down by 1%:

In millions

Unbilled revenue increase (decrease)
Utility margin increase (decrease)(1)
Net loss increase (decrease)(1)
(1) 

Includes impact of regulatory mechanisms including 
decoupling mechanism.

2017

Up 1%

Down 1%

$

$

0.6

0.1

—

(0.6)

(0.1)

—

Derivative Instruments and Hedging Activities  
Our gas acquisition and hedging policies set forth guidelines 
for using financial derivative instruments to support prudent 
risk management strategies. These policies specifically 
prohibit the use of derivatives for trading or speculative 
purposes. We enter into financial derivative contracts to 
hedge a portion of our utility’s natural gas sales 
requirements. These contracts include swaps, options, and 
combinations of option contracts. We primarily use these 
derivative financial instruments to manage commodity price 
variability. A small portion of our derivative hedging strategy 
involves foreign currency exchange contracts. 

Derivative instruments are recorded on our balance sheet at 
fair value. If certain regulatory conditions are met, then the 
derivative instrument fair value is recorded together with an 
offsetting entry to a regulatory asset or liability account 
pursuant to regulatory accounting, and no unrealized gain or 
loss is recognized in current income or loss. See Regulatory 
Accounting above for additional information. The gain or 
loss from the fair value of a derivative instrument subject to 
regulatory deferral is included in the recovery from, or 
refund to, utility customers in future periods. If a derivative 
contract is not subject to regulatory deferral, then the 
accounting treatment for unrealized gains and losses is 
recorded in accordance with accounting standards for 
derivatives and hedging which is either in current income or 
loss or in accumulated other comprehensive income or loss 
(AOCI or AOCL). Our derivative contracts outstanding at 

48

December 31, 2017, 2016 and 2015 were measured at fair 
value using models or other market accepted valuation 
methodologies derived from observable market data. Our 
estimate of fair value may change significantly from period-
to-period depending on market conditions and prices. These 
changes may have an impact on our results of operations, 
but the impact would largely be mitigated due to the majority 
of our derivative activities being subject to regulatory 
deferral treatment. For more information on our derivative 
activity and associated regulatory treatment, see Note 2 and  
Note 13.

The following table summarizes the amount of losses 
realized from commodity price transactions for the last three 
years:

In millions

Net utility loss on:

Commodity

Swaps

2017

2016

2015

$

(7.8) $

(26.9) $

(37.7)

Realized losses from commodity hedges shown above were 
recorded as increases to cost of gas and were, or will be, 
included in our annual PGA rates.

Pensions and Postretirement Benefits
We maintain a qualified non-contributory defined benefit 
pension plan, non-qualified supplemental pension plans for 
eligible executive officers and certain key employees, and 
other postretirement employee benefit plans covering 
certain non-union employees. We also have a qualified 
defined contribution plan (Retirement K Savings Plan) for all 
eligible employees. Only the qualified defined benefit 
pension plan and Retirement K Savings Plan have plan 
assets, which are held in qualified trusts to fund the 
respective retirement benefits. The qualified defined benefit 
retirement plan for union and non-union employees was 
closed to new participants several years ago. These plans 
are not available to employees at any of our subsidiary 
companies. Non-union and union employees hired or re-
hired after December 31, 2006 and 2009, respectively, and 
employees of NW Natural subsidiaries are provided an 
enhanced Retirement K Savings Plan benefit. The 
postretirement Welfare Benefit Plan for non-union 
employees was also closed to new participants several 
years ago.

Net periodic pension and postretirement benefit costs 
(retirement benefit costs) and projected benefit obligations 
(benefit obligations) are determined using a number of key 
assumptions including discount rates, rate of compensation 
increases, retirement ages, mortality rates and an expected 
long-term return on plan assets. See Note 8. 

Accounting standards also require balance sheet 
recognition of the overfunded or underfunded status of 
pension and postretirement benefit plans in AOCI or AOCL, 
net of tax, based on the fair value of plan assets compared 
to the actuarial value of future benefit obligations. However, 
the retirement benefit costs related to our qualified defined 
benefit pension and postretirement benefit plans are 
generally recovered in utility rates, which are set based on 
accounting standards for pensions and postretirement 
benefit expenses. As such, we received approval from the 

  
  
OPUC to recognize the overfunded or underfunded status 
as a regulatory asset or regulatory liability based on 
expected rate recovery, rather than including it as AOCI or 
AOCL under common equity. See "Regulatory Accounting" 
above and Note 2, "Industry Regulation".

We believe our pension assumptions to be appropriate 
based on plan design and an assessment of market 
conditions. However, the following shows the sensitivity of 
our retirement benefit costs and benefit obligations to 
changes in certain actuarial assumptions:

In 2011, we received regulatory approval from the OPUC 
and began deferring a portion of our pension expense 
above or below the amount set in rates to a regulatory 
balancing account on the balance sheet. At December 31, 
2017, the cumulative amount deferred for future pension 
cost recovery was $60.4 million. The regulatory balancing 
account includes the recognition of accrued interest on the 
account balance at the utility's authorized rate of return, with 
the equity portion of this interest being deferred until 
amounts are collected in rates. 

A number of factors, as discussed above, are considered in 
developing pension and postretirement benefit assumptions. 
For the December 31, 2017 measurement date, we 
reviewed and updated:
• 

our weighted-average discount rate assumptions for 
pensions decreased from 4.00% for 2016 to 3.52% for 
2017, and our weighted-average discount rate 
assumptions for other postretirement benefits 
decreased from 3.85% for 2016 to 3.44% for 2017. The 
new rate assumptions were determined for each plan 
based on a matching of benchmark interest rates to the 
estimated cash flows, which reflect the timing and 
amount of future benefit payments. Benchmark interest 
rates are drawn from the Citigroup Above Median 
Curve, which consists of high quality bonds rated AA- or 
higher by S&P or Aa3 or higher by Moody’s;
our expected annual rate of future compensation 
increases, which remained unchanged at a range of 
3.25% to 4.5% at December 31, 2017;
our expected long-term return on qualified defined 
benefit plan assets, which remained unchanged at a 
rate of 7.50%; 
our mortality rate assumptions were updated from 
RP-2006 mortality tables for employees and healthy 
annuitants with a fully generational projection using 
scale MP-2016 to corresponding RP-2006 mortality 
tables using scale MP-2017, which partially offset 
increases of our projected benefit obligation;
other key assumptions, which were based on actual 
plan experience and actuarial recommendations.

• 

• 

• 

• 

At December 31, 2017, our net pension liability (benefit 
obligations less market value of plan assets) for the qualified 
defined benefit plan decreased $4.1 million compared to 
2016. The decrease in our net pension liability is primarily 
due to the $26.2 million increase in our pension benefit 
obligation, offset by an increase of $30.2 million in plan 
assets. The liability for non-qualified plans increased $2.3 
million, and the liability for other postretirement benefits 
decreased $0.5 million in 2017.

We determine the expected long-term rate of return on plan 
assets by averaging the expected earnings for the target 
asset portfolio. In developing our expected return, we 
analyze historical actual performance and long-term return 
projections, which gives consideration to the current asset 
mix and our target asset allocation. 

49

Change in
Assumption

(0.25)%

Dollars in millions

Discount rate:

Qualified defined
benefit plans

Non-qualified plans

Other
postretirement
benefits

Expected long-term
return on plan assets:

(0.25)

Qualified defined
benefit plans

Impact on
2017
Retirement
Benefit
Costs

Impact on
Retirement
Benefit
Obligations
at Dec. 31,
2017

$

1.4

$

—

—

15.2

0.9

0.8

0.7

N/A

In July 2012, President Obama signed into law the MAP-21 
Act. This legislation changed several provisions affecting 
pension plans, including temporary funding relief and 
Pension Benefit Guaranty Corporation (PBGC) premium 
increases, which reduces the level of minimum required 
contributions in the near-term but generally increases 
contributions in the long-run as well as increasing the 
operational costs of running a pension plan. Prior to the 
MAP-21 Act, we were using interest rates based on a 24-
month average yield of investment grade corporate bonds 
(also referred to as "segment rate") to calculate minimum 
contribution requirements. MAP-21 Act established a new 
minimum and maximum corridor for segment rates based on 
a 25-year average of bond yields, which is to be used in 
calculating contribution requirements. In August 2014, 
HATFA was signed and extends certain aspects of MAP-21 
as well as modifies the phase-out periods for the limitations. 
As a result we anticipate lower contributions over the next 
five years with contributions increasing thereafter.

Income Taxes
Valuation Allowances 
We recognize deferred tax assets to the extent that we 
believe these assets are more likely than not to be realized. 
In making such a determination, we consider the available 
positive and negative evidence, including future reversals of 
existing taxable temporary differences, projected future 
taxable income, tax-planning strategies, and results of 
recent operations. We have determined that we are more 
likely than not to realize all recorded deferred tax assets as 
of December 31, 2017. See Note 9.

Uncertain Tax Benefits 
The calculation of our tax liabilities involves dealing with 
uncertainties in the application of complex tax laws and 
regulations in the jurisdictions in which we operate. A tax 
benefit from a material uncertain tax position will only be 
recognized when it is more likely than not that the position, 
or some portion thereof, will be sustained upon examination, 
including resolution of any related appeals or litigation 
processes, on the basis of the technical merits. We 
participate in the Compliance Assurance Process (CAP) 

with the Internal Revenue Service (IRS). Under the CAP 
program the Company works with the IRS to identify and 
resolve material tax matters before the federal income tax 
return is filed each year. No reserves for uncertain tax 
benefits were recorded during 2017, 2016, or 2015. See 
Note 9.

Tax Legislation 
When significant proposed or enacted changes in income 
tax rules occur we consider whether there may be a material 
impact to our financial position, results of operations, cash 
flows, or whether the changes could materially affect 
existing assumptions used in making estimates of tax 
related balances.

On December 22, 2017, H.R.1 - An Act to provide for 
reconciliation pursuant to titles II and V of the concurrent 
resolution on the budget for fiscal year 2018, also known as 
the Tax Cuts and Jobs Act (TCJA), was enacted. The TCJA 
permanently lowers the U.S. federal corporate income tax 
rate to 21% from the existing maximum rate of 35%, 
effective for our tax year beginning January 1, 2018. The 
TCJA includes specific provisions related to regulated public 
utilities that generally provide for the continued deductibility 
of interest expense and the elimination of bonus 
depreciation for property acquired after September 27, 
2017. Certain rate normalization requirements for 
accelerated cost recovery benefits related to regulated plant 
balances also continue. 

The reduced U.S. corporate income tax rate had a material 
impact on our financial statements in 2017. As a result of the 
reduction of the U.S. corporate income tax rate to 21%, U.S. 
GAAP require deferred tax assets and liabilities be revalued 
as of the date of enactment, with resulting tax effects 
accounted for in the reporting period of enactment. We 
recorded a net revaluation of deferred tax asset and liability 
balances of $196.4 million as of December 31, 2017, 
utilizing the reduced federal rate of 21% expected to apply 
when these temporary differences are realized or settled, 
based upon balances in existence at the date of enactment. 
This revaluation had no impact on our 2017 cash flows. See 
Note 9 for more information on how we are impacted by the 
TCJA.

With respect to other tax legislation, the final tangible 
property regulations applicable to all taxpayers were issued 
on September 13, 2013 and were generally effective for 
taxable years beginning on or after January 1, 2014. In 
addition, procedural guidance related to the regulations was 
issued under which taxpayers may make accounting 
method changes to comply with the regulations. We have 
evaluated the regulations and do not anticipate any material 
impact. However, unit-of-property guidance applicable to 
natural gas distribution networks has not yet been issued 
and is expected in the near future. We will further evaluate 
the effect of these regulations after this guidance is issued, 
but believe our current method is materially consistent with 
the new regulations and do not expect this additional 
guidance to have a material effect on our financial 
statements.

Regulatory Matters 
Regulatory tax assets and liabilities are recorded to the 
extent it is probable they will be recoverable from, or 

50

refunded to, customers in future. At December 31, 2017 and 
2016, we had net regulatory income tax assets of $21.3 
million and $43.0 million, respectively, representing flow-
through future rate recovery of deferred tax liabilities 
resulting from differences in utility plant financial statement 
and tax basis and utility plant removal costs. These deferred 
tax liabilities, and the associated regulatory income tax 
assets, are currently being recovered through customer 
rates and were reduced by $17.4 million as a result of the 
TCJA. At December 31, 2017, we had a regulatory income 
tax asset of $0.9 million representing probable future rate 
recovery of deferred tax liabilities resulting from the equity 
portion of AFUDC. This regulatory asset was reduced by 
$0.8 million as a result of the TCJA.

On December 29, 2017, we filed applications with OPUC 
and WUTC seeking authorization to defer the overall net 
benefits of the utility resulting from the TCJA. On the same 
day, Staff of the OPUC filed an application seeking deferral 
of changes in our federal tax obligations resulting from the 
TCJA. On January 8, 2018, the WUTC issued a statement 
acknowledging receipt of our application and indicating their 
intention to incorporate the impact into future rate case 
proceedings.

We have recorded an estimated regulatory liability of $213.7 
million as of December 31, 2017, which includes a gross up 
for income taxes of $56.6 million, for the change in 
regulated utility deferred taxes as a result of the TCJA. The 
TCJA includes specific guidance for determining the 
shortest time period over which the portion of this regulatory 
liability resulting from accelerated cost recovery of utility 
plant may accrue to the benefit of customers to avoid 
incurring federal normalization penalties. However, it is 
anticipated that until such time that customers receive the 
direct benefit of this regulatory liability, the balance, net of 
the additional gross up for income taxes, will continue to 
provide an indirect benefit to customers by reducing the 
utility rate base which determines customer rates for 
service. It is not possible at this time to determine when the 
final resolution of these regulatory proceedings will occur, 
and as result, this regulatory liability is classified as non-
current.   

Utility rates in effect include an allowance to provide for the 
recovery of the anticipated provision for income taxes 
incurred as a result of providing regulated services. The 
provision for income taxes allowance currently in rates 
includes an allowance for federal income taxes determined 
by utilizing the pre-TCJA federal corporate income tax rate 
of 35%. Beginning in 2018, we anticipate that an additional 
regulatory liability will be recorded reflecting the deferral of a 
reduction in our provision for income taxes, incurred as a 
result of providing regulated utility services, due to the newly 
enacted 21% federal corporate income tax rate. 

Environmental Contingencies  
We account for environmental liabilities in accordance with 
accounting standards under the loss contingency guidance 
when it is probable that a liability has been incurred and the 
amount of the loss is reasonably estimable. Amounts 
recorded for environmental contingencies take numerous 
factors into consideration, including, among other variables, 
changes in enacted laws, regulatory orders, estimated 
remediation costs, interest rates, insurance proceeds, 

the strategic evaluation, which included a potential sale in 
the fourth quarter of 2017, we have lowered our views of a 
near-term market recovery and have decreased the 
likelihood associated with contracting with higher-value 
customers. These changes were the most significant 
estimates that caused our cash flow projections to decrease 
to a point where they are no longer sufficient to cover the 
carrying value of the asset. The current assumptions used in 
our fair value model include a significant amount of 
uncertainty in the estimate of future storage values. 
Although we have not seen the rebound in storage prices 
that we originally anticipated, we have worked diligently to 
operate the Gill Ranch Facility efficiently and will continue to 
evaluate all strategic options for the Gill Ranch Facility. Our 
assumptions assume a recovery of the storage market in 
California and an ability to identify and contract with higher-
value customers over the next 5 years, however not to the 
extent previously forecasted.

While many expense assumptions are included in our 
projected cash flows, the most significant assumption is our 
estimated cost and timing of complying with the proposed 
new safety regulations by DOGGR. Although significant, 
these estimates were not considered to be as impactful to 
the fair value of the assets as our estimates of the storage 
revenues referenced above, but are the most significant 
capital expense assumptions. 

Going forward, the two key estimates that could change and 
negatively impact the value of this asset are changes to the 
estimated storage revenues and the cost and timing of 
complying with the new DOGGR regulations. We currently 
assume some recovery of storage prices and assume that 
we will be required to comply with the new DOGGR 
regulations over the next seven years. Additionally, a sale of 
the asset could have an impact on fair value, should one 
occur.

participation by other parties, timing of payments, and the 
input of legal counsel and third-party experts. Accordingly, 
changes in any of these variables or other factual 
circumstances could have a material impact on the amounts 
recorded for our environmental liabilities. For a complete 
discussion of our environmental policy refer to Note 2. For a 
discussion of our current environmental sites and liabilities 
refer to Note 15 and "Contingent Liabilities" above. In 
addition, for information regarding the regulatory treatment 
of these costs and our regulatory recovery mechanism, see 
"Results of Operations—Regulatory Matters—Rate 
Mechanisms—Environmental Costs" above.

Impairment of Long-Lived Assets
We review the carrying value of long-lived assets whenever 
events or changes in circumstances indicate the carrying 
amount of the assets might not be recoverable. Factors that 
would necessitate an impairment assessment of long-lived 
assets include a significant adverse change in the extent or 
manner in which the asset is used, a significant adverse 
change in legal factors or business climate that could affect 
the value of the asset, or a significant decline in the 
observable market value or expected future cash flows of 
the asset, among others. 

When such factors are present, we assess the recoverability 
by determining whether the carrying value of the asset will 
be recovered through expected future cash flows. An asset 
is determined to be impaired when the carrying value of the 
asset exceeds the expected undiscounted future cash flows 
from the use and eventual disposition of the asset. If an 
impairment is indicated, we record an impairment loss for 
the difference between the carrying value and the fair value 
of the long-lived assets. Fair value is estimated using 
appropriate valuation methodologies, which may include an 
estimate of discounted cash flows.

In the fourth quarter of 2017, we recognized a non-cash pre-
tax impairment of long-lived assets at the Gill Ranch Facility 
of $192.5 million, which is included in our gas storage 
segment. We determined circumstances existed that 
indicated the carrying value of the assets may not be 
recoverable. Those circumstances included the completion 
of a comprehensive strategic review process that evaluated 
various alternatives including a potential sale, as well as 
contracting for available storage at lower than anticipated 
values for the coming storage year. Given these 
considerations, management was required to re-evaluate 
the estimated cash flows from our interests in the Gill Ranch 
Facility, and has determined that those estimated cash flows 
are no longer sufficient to cover the carrying value of the 
assets.

We used the income approach to estimate fair value, using 
the estimated future net cash flows. We also compared the 
results of the income approach to our own recent sale 
experience and recent market comparable transactions in 
order to estimate fair value. Many factors and assumptions 
impact the net cash flows used. The most significant and 
uncertain estimates included our forecast of gas storage 
pricing, our ability to successfully identify and contract with 
higher-value customers in and/or near the northern 
California market that Gill Ranch serves, and exploring the 
possibility of providing energy storage services such as 
compressed gas energy storage (CGES). After completing 

51

ITEM 7A. QUANTITATIVE AND QUALITATIVE 
DISCLOSURES ABOUT MARKET RISK

We are exposed to various forms of market risk including 
commodity supply risk, commodity price risk, interest rate 
risk, foreign currency risk, credit risk and weather risk. The 
following describes our exposure to these risks.

Commodity Supply Risk
We enter into spot, short-term, and long-term natural gas 
supply contracts, along with associated pipeline 
transportation contracts, to manage our commodity supply 
risk. Historically, we have arranged for physical delivery of 
an adequate supply of gas, including gas in our Mist storage 
and off-system storage facilities, to meet expected 
requirements of our core utility customers. Our long-term 
gas supply contracts are primarily index-based and subject 
to monthly re-pricing, a strategy that is intended to 
substantially mitigate credit exposure to our physical gas 
counterparties. Absolute notional amounts under physical 
gas contracts related to open positions on our derivative 
instruments were 520.3 million therms and 535.5 million 
therms as of December 31, 2017 and 2016, respectively.

Commodity Price Risk
Natural gas commodity prices are subject to market 
fluctuations due to unpredictable factors including weather, 
pipeline transportation congestion, drilling technologies, 
market speculation, and other factors that affect supply and 
demand. We manage commodity price risk with financial 
swaps and physical gas reserves from a long-term 
investment in working interests in gas leases operated by 
Jonah Energy. These financial hedge contracts and gas 
reserves volumes are generally included in our annual PGA 
filing for recovery, subject to a regulatory prudence review.  
Notional amounts under financial derivative contracts were 
$108.1 million and $123.6 million as of December 31, 2017 
and 2016, respectively. The fair value of financial swaps as 
of December 31, 2017 was an unrealized loss of $22.3 
million with future cash outflows of $14.9 million in 2018, 
$6.0 million in 2019, and $1.4 million in 2020.  

Interest Rate Risk
We are exposed to interest rate risk primarily associated 
with new debt financing needed to fund capital 
requirements, including future contractual obligations and 
maturities of long-term and short-term debt. Interest rate risk 
is primarily managed through the issuance of fixed-rate debt 
with varying maturities. We may also enter into financial 
derivative instruments, including interest rate swaps, options 
and other hedging instruments, to manage and mitigate 
interest rate exposure. We did not have any interest rate 
swaps outstanding as of December 31, 2017 or 2016.

Foreign Currency Risk
The costs of certain pipeline and off-system storage 
services purchased from Canadian suppliers are subject to 
changes in the value of the Canadian currency in relation to 
the U.S. currency. Foreign currency forward contracts are 
used to hedge against fluctuations in exchange rates for our 
commodity-related demand and reservation charges paid in 
Canadian dollars. Notional amounts under foreign currency 
forward contracts were $7.7 million and $7.5 million as of 
December 31, 2017 and 2016, respectively.  If all of the 

52

foreign currency forward contracts had been settled on 
December 31, 2017, a gain of $0.1 million would have been 
realized. See Note 13.

Credit Risk
Credit Exposure to Natural Gas Suppliers 
Certain gas suppliers have either relatively low credit ratings 
or are not rated by major credit rating agencies. To manage 
this supply risk, we purchase gas from a number of different 
suppliers at liquid exchange points. We evaluate and 
monitor suppliers’ creditworthiness and maintain the ability 
to require additional financial assurances, including 
deposits, letters of credit, or surety bonds, in case a supplier 
defaults. In the event of a supplier’s failure to deliver 
contracted volumes of gas, the regulated utility would need 
to replace those volumes at prevailing market prices, which 
may be higher or lower than the original transaction prices. 
We expect these costs would be subject to our PGA sharing 
mechanism discussed above. Since most of our commodity 
supply contracts are priced at the daily or monthly market 
index price tied to liquid exchange points, and we have 
adequate storage flexibility, we believe it is unlikely a 
supplier default would have a material adverse effect on our 
financial condition or results of operations.

Credit Exposure to Financial Derivative Counterparties 
Based on estimated fair value at December 31, 2017, our 
overall credit exposure relating to commodity contracts is 
considered immaterial as it reflects amounts owed to 
financial derivative counterparties (see table below). 
However, changes in natural gas prices could result in 
counterparties owing us money. Therefore, our financial 
derivatives policy requires counterparties to have at least an 
investment-grade credit rating at the time the derivative 
instrument is entered into and specific limits on the contract 
amount and duration based on each counterparty’s credit 
rating. Due to potential changes in market conditions and 
credit concerns, we continue to enforce strong credit 
requirements. We actively monitor and manage our 
derivative credit exposure and place counterparties on hold 
for trading purposes or require cash collateral, letters of 
credit, or guarantees as circumstances warrant. 

The following table summarizes our overall financial swap 
and option credit exposure, based on estimated fair value, 
and the corresponding counterparty credit ratings. The table 
uses credit ratings from S&P and Moody’s, reflecting the 
higher of the S&P or Moody’s rating or a middle rating if the 
entity is split-rated with more than one rating level 
difference:

In millions

AA/Aa

A/A

Total

Financial Derivative Position by Credit Rating
Unrealized Fair Value Gain (Loss)

2017

2016

$

$

(9.0) $

(13.3)

(22.3) $

13.7

1.7

15.4

In most cases, we also mitigate the credit risk of financial 
derivatives by having master netting arrangements with our 
counterparties which provide for making or receiving net 
cash settlements. Generally, transactions of the same type 
in the same currency that have settlement on the same day 
with a single counterparty are netted and a single payment 

  
  
is delivered or received depending on which party is due 
funds.

Additionally, we have master contracts in place with each 
of our derivative counterparties that include provisions for 
posting or calling for collateral. Generally, we can obtain 
cash or marketable securities as collateral with one day’s 
notice. We use various collateral management strategies to 
reduce liquidity risk. The collateral provisions vary by 
counterparty but are not expected to result in the significant 
posting of collateral, if any. We have performed stress tests 
on the portfolio and concluded the liquidity risk from 
collateral calls is not material. Our derivative credit exposure 
is primarily with investment grade counterparties rated AA-/
Aa3 or higher. Contracts are diversified across 
counterparties to reduce credit and liquidity risk.

At December 31, 2017, our financial derivative credit risk on 
a volumetric basis was geographically concentrated 36% in 
the United States and 64% in Canada, based on our 
counterparties' location.  At December 31, 2016, our 
financial derivative credit risk on a volumetric basis was 
geographically concentrated 29% in the United States and 
71% in Canada with our counterparties.

Credit Exposure to Insurance Companies
Our credit exposure to insurance companies for loss or  
damage claims could be material. We regularly monitor the 
financial condition of insurance companies who provide 
general liability insurance policy coverage to NW Natural 
and its predecessors.

Weather Risk 
We have a weather normalization mechanism in Oregon; 
however, we are exposed to weather risk primarily from our 
regulated utility business. A large percentage of our utility 
margin is volume driven, and current rates are based on an 
assumption of average weather. Our weather normalization 
mechanism in Oregon is for residential and commercial 
customers, which is intended to stabilize the recovery of our 
utility’s fixed costs and reduce fluctuations in customers’ bills 
due to colder or warmer than average weather. Customers 
in Oregon are allowed to opt out of the weather 
normalization mechanism. As of December 31, 2017, 
approximately 9% of our Oregon customers had opted out. 
In addition to the Oregon customers opting out, our 
Washington residential and commercial customers account 
for approximately 11% of our total customer base and are 
not covered by weather normalization. The combination of 
Oregon and Washington customers not covered by a 
weather normalization mechanism is 20% of all residential 
and commercial customers. See "Results of Operations—
Regulatory Matters—Rate Mechanisms—WARM" above.

53

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

TABLE OF CONTENTS

1.

2.

3.

4.

5.

Management's Report on Internal Control Over Financial Reporting

Report of Independent Registered Public Accounting Firm

Consolidated Financial Statements:

Consolidated Statements of Comprehensive Income (Loss) for the Years Ended December 31, 2017, 2016, and
2015

Consolidated Balance Sheets at December 31, 2017 and 2016

Consolidated Statements of Shareholders’ Equity for the Years Ended December 31, 2017, 2016, and 2015

Consolidated Statements of Cash Flows for the Years Ended December 31, 2017, 2016, and 2015

Notes to Consolidated Financial Statements

Quarterly Financial Information

Supplementary Data for the Years Ended December 31, 2017, 2016, and 2015:

Financial Statement Schedule

Schedule II – Valuation and Qualifying Accounts and Reserves

Supplemental Schedules Omitted

Page

55

56

57

58

60

61

62

90

90

All other schedules are omitted because of the absence of the conditions under which they are required or because the required 
information is included elsewhere in the financial statements.

54

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
MANAGEMENT’S REPORT ON INTERNAL CONTROL OVER FINANCIAL REPORTING

Management is responsible for establishing and maintaining adequate internal control over financial reporting as defined in 
Rules 13a-15(f) or 15d-15(f) under the Securities Exchange Act of 1934, as amended. Our internal control over financial 
reporting is designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of 
financial statements for external purposes in accordance with generally accepted accounting principles in the United States of 
America (GAAP). Our internal control over financial reporting includes those policies and procedures that:

(i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions 
involving company assets;

(ii) provide reasonable assurance that transactions are recorded as necessary to permit the preparation of financial statements in 
accordance with GAAP, and that receipts and expenditures are being made only in accordance with authorizations of 
management and the Board of Directors; and

(iii) provide reasonable assurance regarding prevention or timely detection of the unauthorized acquisition, use, or disposition of 
our assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements or fraud. 
Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate 
because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Management assessed the effectiveness of our internal control over financial reporting as of December 31, 2017. In making this 
assessment, management used the criteria set forth by the Committee of Sponsoring Organizations of the Treadway 
Commission (COSO) in Internal Control-Integrated Framework (2013).

Based on our assessment and those criteria, management has concluded that we maintained effective internal control over 
financial reporting as of December 31, 2017.

The effectiveness of internal control over financial reporting as of December 31, 2017 has been audited by 
PricewaterhouseCoopers LLP, an independent registered public accounting firm, as stated in their report which appears in this 
annual report.

/s/ David H. Anderson        
David H. Anderson
President and Chief Executive Officer

/s/ Frank H. Burkhartsmeyer  
Frank H. Burkhartsmeyer
Senior Vice President and Chief Financial Officer

February 23, 2018

55

 
 
 
  
 
 
 
 
REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Board of Directors and Shareholders of Northwest Natural Gas Company:

Opinions on the Financial Statements and Internal Control over Financial Reporting

We have audited the accompanying consolidated balance sheets of Northwest Natural Gas Company and its subsidiaries as of 
December 31, 2017 and 2016, and the related consolidated statements of comprehensive income (loss), shareholders’ equity, 
and cash flows for each of the three years in the period ended December 31, 2017 including the related notes and financial 
statement schedule listed in the accompanying index (collectively referred to as the “consolidated financial statements”). We also 
have audited the Company's internal control over financial reporting as of December 31, 2017, based on criteria established in 
Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway 
Commission (COSO). 

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position 
of the Company as of December 31, 2017 and 2016, and the results of their operations and their cash flows for each of the three 
years in the period ended December 31, 2017 in conformity with accounting principles generally accepted in the United States of 
America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting 
as of December 31, 2017, based on criteria established in Internal Control - Integrated Framework (2013) issued by the COSO.

Basis for Opinions

The Company's management is responsible for these consolidated financial statements, for maintaining effective internal control 
over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in the 
accompanying Management's Report on Internal Control over Financial Reporting. Our responsibility is to express opinions on 
the Company’s consolidated financial statements and on the Company's internal control over financial reporting based on our 
audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) 
("PCAOB") and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws 
and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the 
audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, 
whether due to error or fraud, and whether effective internal control over financial reporting was maintained in all material 
respects.  

Our audits of the consolidated financial statements included performing procedures to assess the risks of material misstatement 
of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks.  
Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated 
financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by 
management, as well as evaluating the overall presentation of the consolidated financial statements. Our audit of internal control 
over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a 
material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the 
assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. We 
believe that our audits provide a reasonable basis for our opinions.

Definition and Limitations of Internal Control over Financial Reporting

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the 
reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally 
accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that 
(i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions 
of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit 
preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and 
expenditures of the company are being made only in accordance with authorizations of management and directors of the 
company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or 
disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, 
projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate 
because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

/s/ PricewaterhouseCoopers LLP

Portland, Oregon
February 23, 2018

We have served as the Company’s auditor since 1997. 

56

 
NORTHWEST NATURAL GAS COMPANY
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)

In thousands, except per share data

Operating revenues

Operating expenses:

Cost of gas

Operations and maintenance

Environmental remediation

General taxes

Depreciation and amortization

Impairment expense

Total operating expenses

Income (loss) from operations

Other income (expense), net

Interest expense, net

Income (loss) before income taxes

Income tax expense (benefit)

Net income (loss)

Other comprehensive income (loss):

Change in employee benefit plan liability, net of taxes of $735 for 2017, $452 for
2016, and ($988) for 2015
Amortization of non-qualified employee benefit plan liability, net of taxes of ($374)
for 2017, ($624) for 2016, and ($883) for 2015

Comprehensive income (loss)

Average common shares outstanding:

Basic

Diluted

Earnings (loss) per share of common stock:

Basic

Diluted

Dividends declared per share of common stock

See Notes to Consolidated Financial Statements

Year Ended December 31,

2017

2016

2015

$ 762,173

$ 675,967

$ 723,791

324,795

165,246

15,291

32,012

85,578

192,478

815,400

(53,227)

5,348

38,501

(86,380)

(30,757)

(55,623)

260,588

149,974

13,298

30,538

82,289

—

536,687

139,280

(543)

39,128

99,609

40,714

58,895

327,305

157,521

3,513

30,281

80,923

—

599,543

124,248

7,747

42,539

89,456

35,753

53,703

(2,059)

(744)

1,561

572

955

1,353

$ (57,110) $

59,106

$

56,617

28,669

28,669

27,647

27,779

27,347

27,417

$

(1.94) $

(1.94)

1.88

$

2.13

2.12

1.87

1.96

1.96

1.86

57

NORTHWEST NATURAL GAS COMPANY
CONSOLIDATED BALANCE SHEETS

In thousands

Assets:

Current assets:

Cash and cash equivalents

Accounts receivable

Accrued unbilled revenue

Allowance for uncollectible accounts

Regulatory assets

Derivative instruments

Inventories

Gas reserves

Other current assets

Total current assets

Non-current assets:

Property, plant, and equipment

Less: Accumulated depreciation

Total property, plant, and equipment, net

Gas reserves

Regulatory assets

Derivative instruments

Other investments

Other non-current assets

Total non-current assets

Total assets

As of December 31,

2017

2016

$

3,472

$

68,362

62,381

(956)

45,781

1,735

47,973

15,704

25,484

3,521

66,700

64,946

(1,290)

42,362

17,031

54,129

15,926

24,728

269,936

288,053

3,215,451

3,208,816

960,477

947,916

2,254,974

2,260,900

84,053

356,608

1,306

66,363

6,506

100,184

357,530

3,265

68,376

1,493

2,769,810

2,791,748

$

3,039,746

$

3,079,801

See Notes to Consolidated Financial Statements

58

NORTHWEST NATURAL GAS COMPANY
CONSOLIDATED BALANCE SHEETS

In thousands

Liabilities and equity:

Current liabilities:

Short-term debt

Current maturities of long-term debt

Accounts payable

Taxes accrued

Interest accrued

Regulatory liabilities

Derivative instruments

Other current liabilities

Total current liabilities

Long-term debt

Deferred credits and other non-current liabilities:

Deferred tax liabilities

Regulatory liabilities

Pension and other postretirement benefit liabilities

Derivative instruments

Other non-current liabilities

Total deferred credits and other non-current liabilities

Commitments and contingencies (see Note 14 and Note 15)

Equity:

Common stock - no par value; authorized 100,000 shares; issued and outstanding 28,736
and 28,630 at December 31, 2017 and 2016, respectively

Retained earnings

Accumulated other comprehensive loss

Total equity

Total liabilities and equity

See Notes to Consolidated Financial Statements

As of December 31,

2017

2016

$

54,200

$

96,703

112,308

18,883

6,773

34,013

18,722

40,248

381,850

683,184

270,526

586,093

223,333

4,649

147,335

53,300

39,989

85,664

12,149

5,966

40,290

1,315

35,844

274,517

679,334

557,085

349,319

225,725

913

142,411

1,231,936

1,275,453

448,865

302,349

(8,438)

742,776

445,187

412,261

(6,951)

850,497

$

3,039,746

$

3,079,801

59

 
NORTHWEST NATURAL GAS COMPANY
CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY

In thousands

Balance at December 31, 2014

   Comprehensive income

   Dividends on common stock

   Tax expense from employee stock plans

   Stock-based compensation

   Shares issued pursuant to equity based plans

Balance at December 31, 2015

   Comprehensive income

   Dividends on common stock

   Stock-based compensation
   Shares issued pursuant to equity based plans

   Issuance of common stock, net of issuance costs

Balance at December 31, 2016

   Comprehensive income (loss)

   Dividends on common stock

   Stock-based compensation
   Shares issued pursuant to equity based plans

Common
Stock

Retained
Earnings

Accumulated
Other
Comprehensive
Income (Loss)

Total
Equity

$

375,117

$

402,280

$

(10,076) $

767,321

—

—

(118)

3,277

4,868

383,144

—

—

2,924

6,358

52,761

445,187

—

—

2,882

796

53,703

(50,993)

—

—

—

404,990

58,895

(51,624)

—

—

—

412,261

(55,623)

(54,289)

—

—

2,914

—

—

—

—

(7,162)

211

—

—

—

—

(6,951)

(1,487)

—

—

—

56,617

(50,993)

(118)

3,277

4,868

780,972

59,106

(51,624)

2,924

6,358

52,761

850,497

(57,110)

(54,289)

2,882

796

Balance at December 31, 2017

$

448,865

$

302,349

$

(8,438) $

742,776

See Notes to Consolidated Financial Statements

60

NORTHWEST NATURAL GAS COMPANY
CONSOLIDATED STATEMENTS OF CASH FLOWS

In thousands

Operating activities:

Net income (loss)

Adjustments to reconcile net income (loss) to cash provided by operations:

Depreciation and amortization

Regulatory amortization of gas reserves

Deferred income taxes

Qualified defined benefit pension plan expense

Contributions to qualified defined benefit pension plans

Deferred environmental expenditures, net

Regulatory disallowance of prior environmental cost deferrals

Amortization of environmental remediation

Impairment of long-lived assets

Other

Changes in assets and liabilities:

Receivables, net

Inventories

Income taxes

Accounts payable

Interest accrued

Deferred gas costs

Other, net

Cash provided by operating activities

Investing activities:

Capital expenditures

Other

Cash used in investing activities

Financing activities:

Repurchases related to stock-based compensation

Proceeds from stock options exercised

Proceeds from common stock issued

Long-term debt issued

Long-term debt retired

Change in short-term debt

Cash dividend payments on common stock

Other

Cash provided by (used in) financing activities

(Decrease) increase in cash and cash equivalents

Cash and cash equivalents, beginning of period

Cash and cash equivalents, end of period

Supplemental disclosure of cash flow information:

Interest paid, net of capitalization

Income taxes paid (refunded)

See Notes to Consolidated Financial Statements

61

Year Ended December 31,

2017

2016

2015

$ (55,623) $ 58,895

$ 53,703

85,578

16,353

(52,414)

5,364

82,289

15,525

32,056

5,274

80,923

17,991

26,972

5,697

(19,430)

(14,470)

(14,120)

(13,716)

(10,469)

(10,568)

—

15,291

192,478

3,287

13,298

—

15,000

3,513

—

2,127

3,225

(1,613)

3,099

5,571

6,734

1,424

807

(7,484)

16,620

9,467

12,380

93

2,373

6,964

(6,541)

(17,175)

(206)

17,122

(10,204)

31,918

(4,061)

12,365

(10,143)

206,704

222,147

184,688

(213,595)

(139,511)

(118,320)

(577)

2,882

3,022

(214,172)

(136,629)

(115,298)

(2,034)

(1,042)

4,819

—

8,404

52,760

100,000

150,000

—

3,875

—

—

(40,000)

(25,000)

(60,000)

900

(216,735)

35,335

(53,957)

(51,508)

(49,243)

(2,309)

(3,087)

(4,680)

7,419

(86,208)

(74,713)

(49)

3,521

(690)

4,211

$

3,472

$

3,521

$

(5,323)

9,534

4,211

$ 34,787

$ 36,023

$ 39,634

14,780

(7,157)

17,306

NORTHWEST NATURAL GAS 
COMPANY
NOTES TO CONSOLIDATED FINANCIAL 
STATEMENTS

1. ORGANIZATION AND PRINCIPLES OF 
CONSOLIDATION

The accompanying consolidated financial statements 
represent the consolidated results of Northwest Natural Gas 
Company (NW Natural or the Company) and all companies 
we directly or indirectly control, either through majority 
ownership or otherwise. We have two core businesses: our 
regulated local gas distribution business, referred to as the 
utility segment, which serves residential, commercial, and 
industrial customers in Oregon and southwest Washington; 
and our gas storage businesses, referred to as the gas 
storage segment, which provides storage services for 
utilities, gas marketers, electric generators, and large 
industrial users from facilities located in Oregon and 
California. In addition, we have investments and other non-
utility activities we aggregate and report as other. 

Our core utility business assets and operating activities are 
largely included in the parent company, NW Natural. Our 
direct and indirect wholly-owned subsidiaries include NW 
Natural Energy, LLC (NWN Energy), NW Natural Gas 
Storage, LLC (NWN Gas Storage), Gill Ranch Storage, LLC 
(Gill Ranch), NNG Financial Corporation (NNG Financial), 
Northwest Energy Corporation (Energy Corp), Northwest 
Natural Water Company (NWN Water), FWC Merger Sub, 
Inc., and NWN Gas Reserves LLC (NWN Gas Reserves). 
Investments in corporate joint ventures and partnerships we 
do not directly or indirectly control, and for which we are not 
the primary beneficiary, include NWN Financial's investment 
in Kelso-Beaver Pipeline and NWN Energy's investment in 
Trail West Holdings, LLC (TWH), which is accounted for 
under the equity method. NW Natural and its affiliated 
companies are collectively referred to herein as NW Natural. 
The consolidated financial statements are presented after 
elimination of all intercompany balances and transactions.   
In this report, the term “utility” is used to describe our 
regulated gas distribution business, and the term “non-
utility” is used to describe our gas storage businesses and 
other non-utility investments and business activities.

Certain prior year balances in our consolidated financial 
statements and notes have been reclassified to conform 
with the current presentation. These reclassifications had no 
effect on our prior year’s consolidated results of operations, 
financial condition, or cash flows.

2. SIGNIFICANT ACCOUNTING POLICIES

Use of Estimates 
The preparation of financial statements in conformity with 
generally accepted accounting principles in the United 

States of America (GAAP) requires management to make 
estimates and assumptions that affect reported amounts in 
the consolidated financial statements and accompanying 
notes. Actual amounts could differ from those estimates, and 
changes would most likely be reported in future periods. 
Management believes the estimates and assumptions used 
are reasonable.

Industry Regulation  
Our principal businesses are the distribution of natural gas, 
which is regulated by the OPUC and WUTC, and natural gas 
storage services, which are regulated by either the FERC or 
the CPUC, and to a certain extent by the OPUC and WUTC. 
Accounting records and practices of our regulated 
businesses conform to the requirements and uniform system 
of accounts prescribed by these regulatory authorities in 
accordance with U.S. GAAP. Our businesses regulated by 
the OPUC, WUTC, and FERC earn a reasonable return on 
invested capital from approved cost-based rates, while our 
business regulated by the CPUC earns a return to the extent 
we are able to charge competitive prices above our costs 
(i.e. market-based rates).

In applying regulatory accounting principles, we capitalize or 
defer certain costs and revenues as regulatory assets and 
liabilities pursuant to orders of the OPUC or WUTC, which 
provide for the recovery of revenues or expenses from, or 
refunds to, utility customers in future periods, including a 
return or a carrying charge in certain cases.

At December 31, the amounts deferred as regulatory assets 
and liabilities were as follows:

In thousands

Current:

Regulatory Assets

2017

2016

Unrealized loss on derivatives(1)

$ 18,712

$

Gas costs
Environmental costs(2)
Decoupling(3)

Income taxes
Other(4)

Total current

Non-current:

Unrealized loss on derivatives(1)
Pension balancing(5)

Income taxes

Pension and other postretirement
benefit liabilities
Environmental costs(2)

Gas costs
Decoupling(3)
Other(4)

154

6,198

1,315

6,830

9,989

11,227

13,067

2,218

7,272

4,378

6,783

$ 45,781

$ 42,362

$

4,649

$

913

60,383

19,991

50,863

38,670

179,824

183,035

72,128

63,970

84

3,970

15,579

89

5,860

14,130

Total non-current

$ 356,608

$ 357,530

62

  
 
In thousands

Current:

Gas costs

Unrealized gain on derivatives(1)
Decoupling(3)
Other(4)

Total current

Non-current:

Gas costs
Unrealized gain on derivatives(1)
Decoupling(3)

Income taxes
Accrued asset removal costs(6)
Other(4)

Total non-current

Regulatory Liabilities

2017

2016

$ 14,886

$

8,054

1,674

322

16,624

—

17,131

15,612

$ 34,013

$ 40,290

$

4,630

$

1,021

1,306

957

213,306

3,265

—

—

360,929

341,107

4,965

3,926

$ 586,093

$ 349,319

(1)  Unrealized gains or losses on derivatives are non-cash items 
and, therefore, do not earn a rate of return or a carrying 
charge. These amounts are recoverable through utility rates as 
part of the annual Purchased Gas Adjustment (PGA) 
mechanism when realized at settlement.

(2)  Refer to footnote (3) per the Deferred Regulatory Asset table in 

(3) 

(4) 

Note 15 for a description of environmental costs.
This deferral represents the margin adjustment resulting from 
differences between actual and expected volumes. 
These balances primarily consist of deferrals and amortizations 
under approved regulatory mechanisms. The accounts being 
amortized typically earn a rate of return or carrying charge. 
(5)  Refer to footnote (1) of the Net Periodic Benefit Cost table per 
Note 8 for information regarding the deferral of pension 
expenses. 

(6)  Estimated costs of removal on certain regulated properties are 
collected through rates. See "Accounting Policies—Plant, 
Property, and Accrued Asset Removal Costs" below.  

The amortization period for our regulatory assets and 
liabilities ranges from less than one year to an 
indeterminable period. Our regulatory deferrals for gas costs 
payable are generally amortized over 12 months beginning 
each November 1 following the gas contract year during 
which the deferred gas costs are recorded. Similarly, most of 
our other regulatory deferred accounts are amortized over 
12 months. However, certain regulatory account balances, 
such as income taxes, environmental costs, pension 
liabilities, and accrued asset removal costs, are large and 
tend to be amortized over longer periods once we have 
agreed upon an amortization period with the respective 
regulatory agency.

We believe all costs incurred and deferred at December 31, 
2017 are prudent. We annually review all regulatory assets 
and liabilities for recoverability and more often if 
circumstances warrant. If we should determine that all or a 
portion of these regulatory assets or liabilities no longer meet 
the criteria for continued application of regulatory 
accounting, we would be required to write-off the net 
unrecoverable balances in the period such determination is 
made. 

Environmental Regulatory Accounting 
See Note 15 for information about our SRRM and OPUC 

63

orders regarding implementation. 

New Accounting Standards
We consider the applicability and impact of all accounting 
standards updates (ASUs) issued by the Financial 
Accounting Standards Board (FASB). Accounting standards 
updates not listed below were assessed and determined to 
be either not applicable or are expected to have minimal 
impact on our consolidated financial position or results of 
operations.

Recently Issued Accounting Pronouncements
DERIVATIVES AND HEDGING. On August 28, 2017, the 
FASB issued ASU 2017-12, "Derivatives and Hedging: 
Targeted Improvements to Accounting for Hedging 
Activities." The purpose of the amendment is to more closely 
align hedge accounting with companies’ risk management 
strategies. The ASU amends the accounting for risk 
component hedging, the hedged item in fair value hedges of 
interest rate risk, and amounts excluded from the 
assessment of hedge effectiveness. The guidance also 
amends the recognition and presentation of the effect of 
hedging instruments and includes other simplifications of 
hedge accounting. The amendments in this update are 
effective for us beginning January 1, 2019. Early adoption is 
permitted. The amended presentation and disclosure 
guidance is required prospectively. We are currently 
assessing the effect of this standard on our financial 
statements and disclosures.

STOCK COMPENSATION. On May 10, 2017, the FASB 
issued ASU 2017-09, "Stock Compensation - Scope of 
Modification Accounting." The purpose of the amendment is 
to provide clarity, reduce diversity in practice and reduce the 
cost and complexity when applying the guidance in ASC 
718, related to a change to the terms or conditions of a 
share-based payment award. The ASU amends the scope of 
modification accounting for share-based payment 
arrangements and provides guidance on the types of 
changes to the terms or conditions of share-based payment 
awards to which an entity would be required to apply 
modification accounting under ASC 718. Specifically, an 
entity would not apply modification accounting if the fair 
value, vesting conditions, and classification of the awards 
are the same immediately before and after the modification. 
The amendments in this update are effective for us 
beginning January 1, 2018. The amendments in this update 
should be applied prospectively to an award modified on or 
after the adoption date. We do not expect this standard to 
materially affect our financial statements and disclosures.

RETIREMENT BENEFITS. On March 10, 2017, the FASB 
issued ASU 2017-07, "Improving the Presentation of Net 
Periodic Pension Cost and Net Periodic Post Retirement 
Benefit Cost." The ASU requires entities to disaggregate 
current service cost from the other components of net 
periodic benefit cost and present it with other current 
compensation costs for related employees in the income 
statement and to present the other components elsewhere in 
the income statement and outside of income from operations 
if that subtotal is presented. Only the service cost 
component of the net periodic benefit cost is eligible for 
capitalization. The amendments in this update are effective 
for us beginning January 1, 2018. Upon adoption, the ASU 

requires that changes to the income statement presentation 
of net periodic benefit cost be applied retrospectively, while 
changes to amounts capitalized must be applied 
prospectively. On December 28, 2017, the FERC issued 
Docket AI18-1-000 stating that it will allow entities to change 
their capitalization policy for regulatory accounting and 
reporting purposes to be consistent with the new US GAAP 
requirements. This change will be allowed as a one-time 
policy election upon adoption of the guidance. We have 
elected to adopt the new ASU for FERC regulatory 
accounting and reporting purposes. We anticipate that this 
adoption will reduce amounts capitalized to plant. However, 
this reduction will be largely offset by deferrals to our 
pension regulatory balancing mechanism, and therefore, we 
do not expect this standard to materially affect our financial 
position.

STATEMENT OF CASH FLOWS. On August 26, 2016, the 
FASB issued ASU 2016-15, "Classification of Certain Cash 
Receipts and Cash Payments." The ASU adds guidance 
pertaining to the classification of certain cash receipts and 
payments on the statement of cash flows. The purpose of 
the amendment is to clarify issues that have been creating 
diversity in practice, including the classification of proceeds 
from the settlement of insurance claims and proceeds from 
the settlement of corporate-owned life insurance policies. 
The amendments in this standard are effective for us 
beginning January 1, 2018. We do not expect this standard 
to materially affect our financial statements and disclosures.

LEASES. On February 25, 2016, the FASB issued ASU 
2016-02, "Leases," which revises the existing lease 
accounting guidance. Pursuant to the new standard, lessees 
will be required to recognize all leases, including operating 
leases that are greater than 12 months at lease 
commencement, on the balance sheet and record 
corresponding right-of-use assets and lease liabilities. 
Lessor accounting will remain substantially the same under 
the new standard. Quantitative and qualitative disclosures 
are also required for users of the financial statements to 
have a clear understanding of the nature of our leasing 
activities. The standard is effective for us beginning January 
1, 2019. The new standard must be adopted using a 
modified retrospective transition and provides for certain 
practical expedients. On November 29, 2017, the FASB 
proposed an additional practical expedient that would allow 
entities to apply the transition requirements on the effective 
date of the standard. 

On January 25, 2018, the FASB issued ASU 2018-01, "Land 
Easement Practical Expedient for Transition to Topic 842", to 
address the costs and complexity of applying the transition 
provisions of the new lease standard to land easements. 
This ASU provides an optional practical expedient to not 
evaluate existing or expired land easements that were not 
previously accounted for as leases under the current lease 
guidance. 

We are evaluating additional amendments reached by the 
FASB, and we are currently assessing our lease population 
and material contracts to determine the effect of this 
standard on our financial statements and disclosures. Refer 
to Note 14 for our current lease commitments.

64

FINANCIAL INSTRUMENTS. On January 5, 2016, the FASB 
issued ASU 2016-01, "Financial Instruments - Overall: 
Recognition and Measurement of Financial Assets and 
Financial Liabilities." The ASU enhances the reporting model 
for financial instruments, which includes amendments to 
address aspects of recognition, measurement, presentation, 
and disclosure. The new standard is effective for us 
beginning January 1, 2018. Any impacts as a result of the 
implementation of this ASU will be made through a 
cumulative-effect adjustment to the consolidated balance 
sheet in the first quarter of 2018. We do not expect this 
standard to have a material impact to our financial 
statements and disclosures. 

REVENUE RECOGNITION. On May 28, 2014, the FASB 
issued ASU 2014-09 "Revenue From Contracts with 
Customers." Subsequently, the FASB issued additional, 
clarifying amendments to address issues and questions 
regarding implementation of the new revenue recognition 
standard. The underlying principle of the guidance requires 
entities to recognize revenue depicting the transfer of goods 
or services to customers at amounts the entity is expected to 
be entitled to in exchange for those goods or services. The 
ASU also prescribes a five-step approach to revenue 
recognition: (1) identify the contract(s) with the customer; (2) 
identify the separate performance obligations in the 
contract(s); (3) determine the transaction price; (4) allocate 
the transaction price to separate performance obligations; 
and (5) recognize revenue when, or as, each performance 
obligation is satisfied. The guidance also requires additional 
disclosures, both qualitative and quantitative, regarding the 
nature, amount, timing and uncertainty of revenue and cash 
flows. The new requirements prescribe either a full 
retrospective or modified retrospective adoption method. The 
new standard is effective for us beginning January 1, 2018, 
and we have elected to adopt the standard using the 
modified retrospective approach. We are in the process of 
updating our accounting policies, processes, systems, and 
internal controls as a result of implementing the new 
standard. We have analyzed our revenue streams, material 
contracts with customers, and the expanded disclosure 
requirements under the new standard and determined that 
the standard will not have a material impact on our financial 
position, net income, or cash flows. 

Accounting Policies
Plant, Property, and Accrued Asset Removal Costs 
Plant and property are stated at cost, including capitalized 
labor, materials, and overhead. In accordance with 
regulatory accounting standards, the cost of acquiring and 
constructing long-lived plant and property generally includes 
an allowance for funds used during construction (AFUDC) or 
capitalized interest. AFUDC represents the regulatory 
financing cost incurred when debt and equity funds are used 
for construction (see “AFUDC” below). When constructed 
assets are subject to market-based rates rather than cost-
based rates, the financing costs incurred during construction 
are included in capitalized interest in accordance with U.S. 
GAAP, not as regulatory financing costs under AFUDC.

In accordance with long-standing regulatory treatment, our 
depreciation rates consist of three components: one based 
on the average service life of the asset, a second based on 
the estimated salvage value of the asset, and a third based 

on the asset’s estimated cost of removal. We collect, through 
rates, the estimated cost of removal on certain regulated 
properties through depreciation expense, with a 
corresponding offset to accumulated depreciation. These 
removal costs are non-legal obligations as defined by 
regulatory accounting guidance. Therefore, we have 
included these costs as non-current regulatory liabilities 
rather than as accumulated depreciation on our consolidated 
balance sheets. In the rate setting process, the liability for 
removal costs is treated as a reduction to the net rate base 
on which the regulated utility has the opportunity to earn its 
allowed rate of return.

The costs of utility plant retired or otherwise disposed of are 
removed from utility plant and charged to accumulated 
depreciation for recovery or refund through future rates. 
Gains from the sale of regulated assets are generally 
deferred and refunded to customers. For non-utility assets, 
we record a gain or loss upon the disposal of the property, 
and the gain or loss is recorded in operating income or loss 
in the consolidated statements of comprehensive income or 
loss.

Our provision for depreciation of utility property, plant, and 
equipment is recorded under the group method on a straight-
line basis with rates computed in accordance with 
depreciation studies approved by regulatory authorities. The 
weighted-average depreciation rate for utility assets in 
service was approximately 2.8% for 2017, 2016, and 2015, 
reflecting the approximate weighted-average economic life of 
the property. This includes 2017 weighted-average 
depreciation rates for the following asset categories: 2.7% 
for transmission and distribution plant, 2.3% for gas storage 
facilities, 4.4% for general plant, and 2.7% for intangible and 
other fixed assets.

AFUDC. Certain additions to utility plant include AFUDC, 
which represents the net cost of debt and equity funds used 
during construction. AFUDC is calculated using actual 
interest rates for debt and authorized rates for ROE, if 
applicable. If short-term debt balances are less than the total 
balance of construction work in progress, then a composite 
AFUDC rate is used to represent interest on all debt funds, 
shown as a reduction to interest charges, and on ROE 
funds, shown as other income. While cash is not 
immediately recognized from recording AFUDC, it is realized 
in future years through rate recovery resulting from the 
higher utility cost of service. Our composite AFUDC rate was 
5.5% in 2017, 0.7% in 2016, and 0.4% in 2015.

IMPAIRMENT OF LONG-LIVED ASSETS. We review the 
carrying value of long-lived assets whenever events or 
changes in circumstances indicate the carrying amount of 
the assets may not be recoverable. Factors that would 
necessitate an impairment assessment of long-lived assets 
include a significant adverse change in the extent or manner 
in which the asset is used, a significant adverse change in 
legal factors or business climate that could affect the value of 
the asset, or a significant decline in the observable market 
value or expected future cash flows of the asset, among 
others. 

When such factors are present, we assess the recoverability 
by determining whether the carrying value of the asset will 

65

be recovered through expected future cash flows. An asset 
is determined to be impaired when the carrying value of the 
asset exceeds the expected undiscounted future cash flows 
from the use and eventual disposition of the asset. If an 
impairment is indicated, we record an impairment loss for the 
difference between the carrying value and the fair value of 
the long-lived assets. Fair value is estimated using 
appropriate valuation methodologies, which may include an 
estimate of discounted cash flows.

In the fourth quarter of 2017, we recognized a non-cash pre-
tax impairment of long-lived assets at the Gill Ranch Facility 
of $192.5 million, which is included in our gas storage 
segment. We determined circumstances existed that 
indicated the carrying value of the assets may not be 
recoverable. Those circumstances included the completion 
of a comprehensive strategic review process that evaluated 
various alternatives including a potential sale, as well as 
contracting for available storage at lower than anticipated 
values for the coming storage year. Given these 
considerations, management was required to re-evaluate the 
estimated cash flows from our interests in the Gill Ranch 
Facility, and has determined that those estimated cash flows 
are no longer sufficient to cover the carrying value of the 
assets. We did not recognize any impairments in 2016 or 
2015.

We used the income approach to estimate fair value, using 
the estimated future net cash flows of the Gill Ranch Facility. 
We also compared the results of the income approach to our 
own recent sale process experience and recent market 
comparable transactions in order to estimate fair value.  

Cash and Cash Equivalents  
For purposes of reporting cash flows, cash and cash 
equivalents include cash on hand plus highly liquid 
investment accounts with original maturity dates of three 
months or less. At December 31, 2017 and 2016, 
outstanding checks of approximately $4.8 million and $2.9 
million, respectively, were included in accounts payable.

Revenue Recognition and Accrued Unbilled Revenue
Utility revenues, derived primarily from the sale and 
transportation of natural gas, are recognized upon delivery of 
the gas commodity or service to customers. Revenues 
include accruals for gas delivered but not yet billed to 
customers based on estimates of deliveries from meter 
reading dates to month end (accrued unbilled revenue). 
Accrued unbilled revenue is dependent upon a number of 
factors that require management’s judgment, including total 
gas receipts and deliveries, customer use by billing cycle, 
and weather factors. Accrued unbilled revenue is reversed 
the following month when actual billings occur. Our accrued 
unbilled revenue at December 31, 2017 and 2016 was $62.4 
million and $64.9 million, respectively.

Non-utility revenues are derived primarily from the gas 
storage segment. At our Mist underground storage facility, 
revenues are primarily firm service revenues in the form of 
fixed monthly reservation charges. At the Gill Ranch Facility, 
firm storage services resulting from short-term and long-term 
contracts are typically recognized in revenue ratably over the 
term of the contract regardless of the actual storage capacity 
utilized. In addition, we also have asset management service 

  
 
revenue from an independent energy marketing company 
that optimizes commodity, storage, and pipeline capacity 
release transactions. Under this agreement, guaranteed 
asset management revenue is recognized using a straight-
line, pro-rata methodology over the term of each contract. 
Revenues earned above the guaranteed amount are 
recognized as they are earned. 

Revenue Taxes 
Revenue-based taxes are primarily franchise taxes, which 
are collected from customers and remitted to taxing 
authorities. Revenue taxes are included in operating 
revenues in the statement of comprehensive income or loss. 
Revenue taxes were $19.1 million, $17.1 million, and $18.0 
million for 2017, 2016, and 2015, respectively.  

Accounts Receivable and Allowance for Uncollectible 
Accounts 
Accounts receivable consist primarily of amounts due for 
natural gas sales and transportation services to utility 
customers, plus amounts due for gas storage services. We 
establish an allowance for uncollectible accounts (allowance) 
for trade receivables, including accrued unbilled revenue, 
based on the aging of receivables, collection experience of 
past due account balances including payment plans, and 
historical trends of write-offs as a percent of revenues. A 
specific allowance is established and recorded for large 
individual customer receivables when amounts are identified 
as unlikely to be partially or fully recovered. Inactive 
accounts are written-off against the allowance after they are 
120 days past due or when deemed uncollectible. 
Differences between our estimated allowance and actual 
write-offs will occur based on a number of factors, including 
changes in economic conditions, customer creditworthiness, 
and natural gas prices. The allowance for uncollectible 
accounts is adjusted quarterly, as necessary, based on 
information currently available.

Inventories  
Utility gas inventories, which consist of natural gas in storage 
for the utility, are stated at the lower of average cost or net 
realizable value. The regulatory treatment of utility gas 
inventories provides for cost recovery in customer rates. 
Utility gas inventories injected into storage are priced in 
inventory based on actual purchase costs. Utility gas 
inventories withdrawn from storage are charged to cost of 
gas during the current period they are withdrawn at the 
weighted-average inventory cost.

Gas storage inventories, which primarily represent 
inventories at the Gill Ranch Facility, mainly consist of 
natural gas received as fuel-in-kind from storage customers. 
Gas storage inventories are valued at the lower of average 
cost or net realizable value. Cushion gas is not included in 
our inventory balances, is recorded at original cost, and is 
classified as a long-term plant asset.

Materials and supplies inventories consist of both utility and 
non-utility inventories and are stated at the lower of average 
cost or net realizable value.

Our utility and gas storage inventories totaled $36.7 million 
and $42.7 million at December 31, 2017 and 2016, 
respectively. At December 31, 2017 and 2016, our materials 

66

and supplies inventories totaled $11.3 million and $11.4 
million, respectively.

Gas Reserves
Gas reserves are payments to acquire and produce natural 
gas reserves. Gas reserves are stated at cost, adjusted for 
regulatory amortization, with the associated deferred tax 
benefits recorded as liabilities on the balance sheet. The 
current portion is calculated based on expected gas 
deliveries within the next fiscal year. We recognize regulatory 
amortization of this asset on a volumetric basis calculated 
using the estimated gas reserves and the estimated therms 
extracted and sold each month. The amortization of gas 
reserves is recorded to cost of gas along with gas production 
revenues and production costs. See Note 11.

Derivatives  
Derivatives are measured at fair value and recognized as 
either assets or liabilities on the balance sheet. Changes in 
the fair value of the derivatives are recognized currently in 
earnings unless specific regulatory or hedge accounting 
criteria are met. Accounting for derivatives and hedges 
provides an exception for contracts intended for normal 
purchases and normal sales for which physical delivery is 
probable. In addition, certain derivative contracts are 
approved by regulatory authorities for recovery or refund 
through customer rates. Accordingly, the changes in fair 
value of these approved contracts are deferred as regulatory 
assets or liabilities pursuant to regulatory accounting 
principles. Our financial derivatives generally qualify for 
deferral under regulatory accounting. Our index-priced 
physical derivative contracts also qualify for regulatory 
deferral accounting treatment.

Derivative contracts entered into for utility requirements after 
the annual PGA rate has been set and maturing during the 
PGA year are subject to the PGA incentive sharing 
mechanism. In Oregon we participate in a PGA sharing 
mechanism under which we are required to select either an 
80% or 90% deferral of higher or lower gas costs such that 
the impact on current earnings from the gas cost sharing is 
either 20% or 10% of gas cost differences compared to PGA 
prices, respectively. For the PGA years in Oregon beginning 
November 1, 2017, 2016, and 2015, we selected the 90%, 
90%, and 80% deferral of gas cost differences, respectively. 
In Washington, 100% of the differences between the PGA 
prices and actual gas costs are deferred. See Note 13.

Our financial derivatives policy sets forth the guidelines for 
using selected derivative products to support prudent risk 
management strategies within designated parameters. Our 
objective for using derivatives is to decrease the volatility of 
gas prices, earnings, and cash flows without speculative risk. 
The use of derivatives is permitted only after the risk 
exposures have been identified, are determined not to 
exceed acceptable tolerance levels, and are determined 
necessary to support normal business activities. We do not 
enter into derivative instruments for trading purposes.

Fair Value  
In accordance with fair value accounting, we use the 
following fair value hierarchy for determining inputs for our 
debt, pension plan assets, and our derivative fair value 
measurements:

• 

• 

• 

Level 1: Valuation is based on quoted prices for identical 
instruments traded in active markets;
Level 2: Valuation is based on quoted prices for similar 
instruments in active markets, quoted prices for identical 
or similar instruments in markets that are not active, and 
model-based valuation techniques for which all 
significant assumptions are observable in the market; 
and
Level 3: Valuation is generated from model-based 
techniques that use significant assumptions not 
observable in the market. These unobservable 
assumptions reflect our own estimates of assumptions 
market participants would use in valuing the asset or 
liability.

When developing fair value measurements, it is our policy to 
use quoted market prices whenever available or to maximize 
the use of observable inputs and minimize the use of 
unobservable inputs when quoted market prices are not 
available. Fair values are primarily developed using industry-
standard models that consider various inputs including: (a) 
quoted future prices for commodities; (b) forward currency 
prices; (c) time value; (d) volatility factors; (e) current market 
and contractual prices for underlying instruments; (f) market 
interest rates and yield curves; (g) credit spreads; and (h) 
other relevant economic measures. The Company considers 
liquid points for its natural gas hedging to be those points for 
which there are regularly published prices in a nationally 
recognized publication or where the instruments are traded 
on an exchange.

Income Taxes  
We account for income taxes under the asset and liability 
method, which requires the recognition of deferred tax 
assets and liabilities for the expected future tax 
consequences of events that have been included in the 
financial statements. Under this method, deferred tax assets 
and liabilities are determined on the basis of the differences 
between the financial statement and tax basis of assets and 
liabilities using enacted tax rates in effect for the year in 
which the differences are expected to reverse. The effect of 
a change in tax rates on deferred tax assets and liabilities is 
recognized in income in the enactment date period unless a 
regulatory Order specifies deferral of the effect of the change 
in tax rates over a longer period of time.  

Deferred income tax assets and liabilities are also 
recognized for temporary differences where the deferred 
income tax benefits or expenses have previously been 
flowed through in the ratemaking process of the regulated 
utility. Regulatory tax assets and liabilities are recorded on 

these deferred tax assets and liabilities to the extent we 
believe they will be recoverable from or refunded to 
customers in future rates. 

Deferred investment tax credits on utility plant additions, 
which reduce income taxes payable, are deferred for 
financial statement purposes and amortized over the life of 
the related plant. 

We recognize interest and penalties related to unrecognized 
tax benefits, if any, within income tax expense and accrued 
interest and penalties within the related tax liability line in the 
consolidated balance sheets. No accrued interest or 
penalties for uncertain tax benefits have been recorded. See 
Note 9. 

Environmental Contingencies  
Loss contingencies are recorded as liabilities when it is 
probable a liability has been incurred and the amount of the 
loss is reasonably estimable in accordance with accounting 
standards for contingencies. Estimating probable losses 
requires an analysis of uncertainties that often depend upon 
judgments about potential actions by third parties. Accruals 
for loss contingencies are recorded based on an analysis of 
potential results. 

With respect to environmental liabilities and related costs, 
we develop estimates based on a review of information 
available from numerous sources, including completed 
studies and site specific negotiations. It is our policy to 
accrue the full amount of such liability when information is 
sufficient to reasonably estimate the amount of probable 
liability. When information is not available to reasonably 
estimate the probable liability, or when only the range of 
probable liabilities can be estimated and no amount within 
the range is more likely than another, it is our policy to 
accrue at the low end of the range. Accordingly, due to 
numerous uncertainties surrounding the course of 
environmental remediation and the preliminary nature of 
several site investigations, in some cases, we may not be 
able to reasonably estimate the high end of the range of 
possible loss. In those cases, we have disclosed the nature 
of the potential loss and the fact that the high end of the 
range cannot be reasonably estimated. See Note 15.

Subsequent Events
We monitor significant events occurring after the balance 
sheet date and prior to the issuance of the financial 
statements to determine the impacts, if any, of events on the 
financial statements to be issued. We do not have any 
subsequent events to report.

67

3. EARNINGS PER SHARE

Basic earnings or loss per share are computed using net 
income or loss and the weighted average number of 
common shares outstanding for each period presented. 
Diluted earnings per share are computed in the same 

manner, except it uses the weighted average number of 
common shares outstanding plus the effects of the 
assumed exercise of stock options and the payment of 
estimated stock awards from other stock-based 
compensation plans that are outstanding at the end of each 
period presented. 

Antidilutive stock awards are excluded from the calculation of diluted earnings or loss per common share. Diluted earnings or 
loss per share are calculated as follows:

In thousands, except per share data

Net income (loss)

Average common shares outstanding - basic

Additional shares for stock-based compensation plans (See Note 6)

Average common shares outstanding - diluted

Earnings (loss) per share of common stock - basic

Earnings (loss) per share of common stock - diluted

Additional information:

Antidilutive shares

4. SEGMENT INFORMATION

We primarily operate in two reportable business segments: 
local gas distribution and gas storage. We also have other 
investments and business activities not specifically related 
to one of these two reporting segments, which are 
aggregated and reported as other. We refer to our local gas 
distribution business as the utility, and our gas storage 
segment and other as non-utility. Our utility segment also 
includes the utility portion of our Mist underground storage 
facility and our North Mist gas storage expansion in Oregon 
and NWN Gas Reserves, which is a wholly-owned 
subsidiary of Energy Corp. Our gas storage segment 
includes NWN Gas Storage, which is a wholly-owned 
subsidiary of NWN Energy, Gill Ranch, which is a wholly-
owned subsidiary of NWN Gas Storage, the non-utility 
portion of Mist, and all third-party asset management 
services. Other includes NNG Financial, non-utility 
appliance retail center operations, NWN Water, which is 
pursuing investments in the water sector itself and through 
its wholly-owned subsidiary FWC Merger Sub, Inc., and 
NWN Energy's equity investment in TWH, which is pursuing 
development of a cross-Cascades transmission pipeline 
project. No individual customer accounts for over 10% of 
our operating revenues.

Local Gas Distribution
Our local gas distribution segment is a regulated utility 
principally engaged in the purchase, sale, and delivery of 
natural gas and related services to customers in Oregon 
and southwest Washington. As a regulated utility, we are 
responsible for building and maintaining a safe and reliable 
pipeline distribution system, purchasing sufficient gas 
supplies from producers and marketers, contracting for firm 
and interruptible transportation of gas over interstate 
pipelines to bring gas from the supply basins into our 
service territory, and re-selling the gas to customers subject 
to rates, terms, and conditions approved by the OPUC or 
WUTC. Gas distribution also includes taking customer-
owned gas and transporting it from interstate pipeline 
connections, or city gates, to the customers’ end-use 
facilities for a fee, which is approved by the OPUC or 

2017

2016

2015

$

(55,623) $

58,895

$

28,669

—

28,669

27,647

132

27,779

$

$

(1.94) $

(1.94) $

2.13

2.12

$

$

53,703

27,347

70

27,417

1.96

1.96

97

5

12

WUTC. Approximately 89% of our customers are located in 
Oregon and 11% in Washington. On an annual basis, 
residential and commercial customers typically account for 
around 60% of our utility’s total volumes delivered and 90% 
of our utility’s margin. Industrial customers largely account 
for the remaining volumes and utility margin. A small 
amount of utility margin is also derived from miscellaneous 
services, gains or losses from an incentive gas cost sharing 
mechanism, and other service fees.

Industrial sectors we serve include: pulp, paper, and other 
forest products; the manufacture of electronic, 
electrochemical and electrometallurgical products; the 
processing of farm and food products; the production of 
various mineral products; metal fabrication and casting; the 
production of machine tools, machinery, and textiles; the 
manufacture of asphalt, concrete, and rubber; printing and 
publishing; nurseries; government and educational 
institutions; and electric generation.

Gas Storage
Our gas storage segment includes natural gas storage 
services provided to customers primarily from two 
underground natural gas storage facilities: the Gill Ranch 
Facility and the non-utility portion of our Mist gas storage 
facility. In addition to earning revenue from customer 
storage contracts, we also use an independent energy 
marketing company to provide asset management services 
for utility and non-utility capacity, the results of which are 
included in this business segment. 

Mist Gas Storage Facility
Earnings from non-utility assets at our Mist facility in 
Oregon are primarily related to firm storage capacity 
revenues. Earnings for the Mist facility also include 
revenue, net of amounts shared with utility customers, from 
management of utility assets at Mist and upstream pipeline 
capacity when not needed to serve utility customers. We 
retain 80% of the pre-tax income from these services when 
the costs of the capacity have not been included in utility 
rates, or 33% of the pre-tax income when the costs have 
been included in utility rates. The remaining 20% and 67%, 

68

respectively, are recorded to a deferred regulatory account 
for crediting back to utility customers. 

Gill Ranch Gas Storage Facility
Gill Ranch has a joint project agreement with Pacific 
Gas and Electric Company (PG&E) to own and operate the 
Gill Ranch Facility, an underground natural gas storage 
facility near Fresno, California. Gill Ranch has a 75% 
undivided ownership interest in the facility and is also the 
operator of the facility, which offers storage services to the 
California market at market-based rates, subject to CPUC 
regulation including, but not limited to, service terms and 
conditions and tariff regulations. Although this is a jointly-
owned property, each owner is independently responsible 
for financing its share of the Gill Ranch Facility. As such, the 
impairment of long-lived assets at the Gill Ranch Facility 
recognized in 2017 reflects our ownership interest. 
Revenues are primarily related to firm storage capacity as 
well as asset management revenues.

Other
We have non-utility investments and other business 
activities, which are aggregated and reported as other. 
Other primarily consists of an equity method investment in 
TWH, which was formed to build and operate an interstate 
gas transmission pipeline in Oregon (TWP), other pipeline 
assets in NNG Financial, and non-utility appliance retail 
center operations. For more information on TWP, see Note 
12. Other also includes some corporate operating and non-
operating revenues and expenses that cannot be allocated 
to utility operations. Upon closing agreements to purchase 
two water utilities, we expect them to be accounted for as 
other.

NNG Financial's assets primarily consist of an active, 
wholly-owned subsidiary which owns a 10% interest in an 
18-mile interstate natural gas pipeline. NNG Financial’s 
total assets were $0.4 million and $0.5 million at December 
31, 2017 and 2016, respectively.

Segment Information Summary
Inter-segment transactions were immaterial for the periods presented. The following table presents summary financial 
information concerning the reportable segments:

In thousands

2017

Utility

Gas Storage

Other

Total

Operating revenues

$

732,942

$

23,620

$

5,611

$

Depreciation and amortization
Income (loss) from operations (1)
Net income (loss) (2)

Capital expenditures

Total assets at December 31, 2017

2016

79,734

132,807

60,509

211,672

2,961,326

5,844

(185,074)

(116,209)

1,923

59,583

—

(960)

77

—

762,173

85,578

(53,227)

(55,623)

213,595

18,837

3,039,746

Operating revenues

$

650,477

$

25,266

$

224

$

Depreciation and amortization

Income (loss) from operations
Net income (loss) (3)

Capital expenditures

76,289

130,570

54,567

138,074

6,000

9,136

4,303

1,437

—

(426)

25

—

675,967

82,289

139,280

58,895

139,511

Total assets at December 31, 2016

2,806,627

256,333

16,841

3,079,801

2015

Operating revenues

$

702,210

$

21,356

$

225

$

Depreciation and amortization

Income (loss) from operations
Net income (loss) (3)

Capital expenditures

74,410

119,215

53,391

115,272

6,513

5,032

174

3,048

—

1

138

—

723,791

80,923

124,248

53,703

118,320

Total assets at December 31, 2015

2,791,623

261,750

16,037

3,069,410

(1)  
(2)  

(3) 

Includes $192.5 million for an impairment of long-lived assets at the Gill Ranch Facility in Gas Storage.
Includes $21.9 million and $0.6 million of tax benefit in Gas Storage and Other, respectively, and $1.0 million of tax expense in Utility from 
the enactment of TCJA. Gas Storage also includes an after-tax impairment of long-lived assets at the Gill Ranch Facility of $141.5 million. 
The TCJA was enacted December 22, 2017 and resulted in the federal tax rate changing from 35% to 21%. The after-tax impairment 
charge is calculated using our new combined federal and state statutory rate of 26.5%.
Includes $2.0 million in 2016 and $9.1 million in 2015 of after-tax regulatory environmental disallowance charges in Utility.

Utility Margin
Utility margin is a financial measure consisting of utility 
operating revenues, which are reduced by revenue taxes, 
the associated cost of gas, and environmental recovery 
revenues. The cost of gas purchased for utility customers is 
generally a pass-through cost in the amount of revenues 
billed to regulated utility customers. Environmental recovery 
revenues represent collections received from customers 

through our environmental recovery mechanism in Oregon. 
These collections are offset by the amortization of 
environmental liabilities, which is presented as 
environmental remediation expense in our operating 
expenses. By subtracting cost of gas and environmental 
remediation expense from utility operating revenues, utility 
margin provides a key metric used by our chief operating 
decision maker in assessing the performance of the utility 

69

 
segment. The gas storage segment and other emphasize 
growth in operating revenues as opposed to margin 
because they do not incur a product cost (i.e. cost of gas 

sold) like the utility and, therefore, use operating revenues 
and net income to assess performance.

The following table presents additional segment information concerning utility margin:

In thousands

Utility margin calculation:

Utility operating revenues

Less: Utility cost of gas

          Environmental remediation expense

Utility margin

5. COMMON STOCK

Common Stock
As of December 31, 2017 and 2016, we had 100 million 
shares of common stock authorized. As of December 31, 
2017, we had reserved 43,058 shares for issuance of 
common stock under the Employee Stock Purchase Plan 
(ESPP) and 155,086 shares under our Dividend 
Reinvestment and Direct Stock Purchase Plan (DRPP).  At 
our election, shares sold through our DRPP may be 
purchased in the open market or through original issuance 
of shares reserved for issuance under the DRPP.

The Restated Stock Option Plan (SOP) was terminated with 
respect to new grants in 2012; however, options granted 
before the Restated SOP was terminated will remain 
outstanding until the earlier of their expiration, forfeiture, or 
exercise. There were 91,688 options outstanding at 
December 31, 2017, which were granted prior to termination 
of the plan. 

During November 2016, we completed an equity issuance 
consisting of an offering of 880,000 shares of its common 
stock along with a 30-day option for the underwriters to 
purchase an additional 132,000 shares. The offering closed 
on November 16, 2016 and resulted in a total issuance of 
1,012,000 shares as both the initial offering and the 
underwriter option were fully executed. All shares were 
issued on November 16, 2016 at an offering price of $54.63 
per share and resulted in total net proceeds of $52.8 million.

Stock Repurchase Program
We have a share repurchase program under which we may 
purchase our common shares on the open market or 
through privately negotiated transactions. We currently have 
Board authorization through May 2018 to repurchase up to 
an aggregate of the greater of 2.8 million shares or $100 
million. No shares of common stock were repurchased 
pursuant to this program during the year ended December 
31, 2017. Since the plan’s inception in 2000, a total of 2.1 
million shares have been repurchased at a total cost of 
$83.3 million.

2017

2016

2015

$

$

732,942

$

650,477

$

325,019

15,291

260,588

13,298

702,210

327,305

3,513

392,632

$

376,591

$

371,392

Summary of Changes in Common Stock
The following table shows the changes in the number of 
shares of our common stock issued and outstanding:

In thousands

Balance, December 31, 2014

   Sales to employees under ESPP

Stock-based compensation

   Sales to shareholders under DRPP

Balance, December 31, 2015

   Sales to employees under ESPP

Stock-based compensation

   Equity Issuance

Balance, December 31, 2016

   Sales to employees under ESPP

Stock-based compensation

Balance, December 31, 2017

Shares

27,284

19

78

46

27,427

18

173

1,012

28,630

18

88

28,736

6. STOCK-BASED COMPENSATION

Our stock-based compensation plans are designed to 
promote stock ownership in NW Natural by employees and 
officers. These compensation plans include a Long Term 
Incentive Plan (LTIP), an ESPP, and a Restated SOP. 

Long Term Incentive Plan
The LTIP is intended to provide a flexible, competitive 
compensation program for eligible officers and key 
employees. Under the LTIP, shares of common stock are 
authorized for equity incentive grants in the form of stock, 
restricted stock, restricted stock units, stock options, or 
performance shares. An aggregate of 1,100,000 shares 
were authorized for issuance as of December 31, 2017. 
Shares awarded under the LTIP may be purchased on the 
open market or issued as original shares. 

Of the 1,100,000 shares of common stock authorized for 
LTIP awards at December 31, 2017, there were 626,960 
shares available for issuance under any type of award. This 
assumes market, performance, and service-based grants 
currently outstanding are awarded at the target level. There 
were no outstanding grants of restricted stock or stock 
options under the LTIP at December 31, 2017 or 2016. The 
LTIP stock awards are compensatory awards for which 
compensation expense is based on the fair value of stock 
awards, with expense being recognized over the 

70

performance and vesting period of the outstanding awards. 
Forfeitures are recognized as they occur.

Performance Shares
Since the LTIP’s inception in 2001, performance shares, 
which incorporate market, performance, and service-based 
factors, have been granted annually with three-year 
performance periods. The following table summarizes 
performance share expense information:

Dollars in thousands

Estimated award:

2015-2017 grant(3)

Actual award:

2014-2016 grant

2013-2015 grant

Shares(1) 

Expense 
During Award 
Year(2)

Total
Expense
for Award

18,300

$

(346) $

1,169

31,388

8,914

168

312

1,685

1,240

(1)  

In addition to common stock shares, a participant also 
receives a dividend equivalent cash payment equal to the 
number of shares of common stock received on the award 
payout multiplied by the aggregate cash dividends paid per 
share during the performance period. 

(2)   Amount represents the expense recognized in the third year of 

(3) 

the vesting period noted above. For the 2015-2017 grant, we 
did not meet targets and reversed expense during 2017 that 
had been previously recognized.
This represents the estimated number of shares to be 
awarded as of December 31, 2017 as certain performance 
share measures had been achieved. Amounts are subject to 
change with final payout amounts authorized by the Board of 
Directors in February 2018.

The aggregate number of performance shares granted and 
outstanding at the target and maximum levels were as 
follows:

Dollars in
thousands

Performance
Period

Performance Share
Awards Outstanding

2017

Cumulative
Expense

Target

Maximum

Expense/
(Reversal)

December
31, 2017

59,934

$

(346) $

1,169

2015-17

2016-18

2017-19

Total

29,967

24,826

32,680

49,652

65,360

87,473

174,946

$

337

942

933

815

942

For the 2015-2017 and 2016-2018 plan years, performance 
share awards are based on EPS and Return on Invested 
Capital (ROIC) factors and a total shareholder return (TSR 
factor) relative to the Dow Jones U.S. Gas Distribution peer 
group over the three-year performance period. Additionally, 
these plans are based on performance results achieved 
relative to specific core and non-core strategies (strategic 
factor). For the 2017-2019 plan year, performance share 
awards are based on the achievement of EPS and ROIC 
factors, which can be modified by a TSR factor relative to 
the performance of the Russell 2500 Utilities Index over the 
three-year performance period and a growth modifier based 
on accumulative EBITA measure. 

Compensation expense is recognized in accordance with 
accounting standards for stock-based compensation and 
calculated based on performance levels achieved and an 

71

estimated fair value using the Monte-Carlo method. The 
weighted-average grant date fair value of nonvested shares 
at December 31, 2017 and 2016 was $56.40 and $50.83 per 
share, respectively. The weighted-average grant date fair 
value of shares granted during the year was $57.05 per 
share and for shares vested during the year was $52.02 per 
share. As of December 31, 2017, there was $2.8 million of 
unrecognized compensation expense related to the 
nonvested portion of performance awards expected to be 
recognized through 2019. 

Restricted Stock Units
In 2012, we began granting RSUs under the LTIP instead of 
stock options under the Restated SOP. Generally, the RSUs 
awarded are forfeitable and include a performance-based 
threshold as well as a vesting period of four years from the 
grant date. Upon vesting, the RSU holder is issued one 
share of common stock plus a cash payment equal to the 
total amount of dividends paid per share between the grant 
date and vesting date of that portion of the RSU. The fair 
value of an RSU is equal to the closing market price of the 
Company's common stock on the grant date. During 2017, 
total RSU expense was $1.6 million compared to $1.5 
million in 2016 and $1.3 million in 2015. As of December 31, 
2017, there was $3.1 million of unrecognized compensation 
cost from grants of RSUs, which is expected to be 
recognized over a period extending through 2022. 

Information regarding the RSU activity is summarized as 
follows:

Number
of
RSUs

Weighted -
Average
Price Per 
RSU

Nonvested, December 31, 2014

70,794

$

Granted

Vested

Forfeited

Nonvested, December 31, 2015

Granted

Vested

Forfeited

Nonvested, December 31, 2016

Granted

Vested

Forfeited

Nonvested, December 31, 2017

37,264

(19,003)

(468)

88,587

40,271

(29,488)

(9,397)

89,973

32,168

(35,341)

(2,278)

84,522

44.00

46.29

44.81

44.99

44.78

54.36

45.56

44.59

48.85

60.51

47.07

53.78

53.90

Restated Stock Option Plan
The Restated SOP was terminated for new option grants in 
2012; however, options granted before the plan terminated 
will remain outstanding until the earlier of their expiration, 
forfeiture, or exercise. Any new grants of stock options 
would be made under the LTIP, however, no option grants 
have been awarded since 2012 and all stock options were 
vested as of December 31, 2015.

Options under the Restated SOP were granted to officers 
and key employees designated by a committee of our Board 
of Directors. All options were granted at an option price 
equal to the closing market price on the date of grant and 

may be exercised for a period of up to 10 years and seven 
days from the date of grant. Option holders may exchange 
shares they have owned for at least six months, valued at 
the current market price, to purchase shares at the option 
price.

Information regarding the Restated SOP activity is 
summarized as follows:

Weighted -
Average
Price Per 
Share

Intrinsic
Value
(In millions)

Option
Shares

Balance outstanding,
December 31, 2014

416,088

$

43.40

$

Exercised

Forfeited

Balance outstanding,
December 31, 2015

Exercised

Forfeited

Balance outstanding,
December 31, 2016

Exercised

Forfeited

Balance outstanding
and exercisable,
December 31, 2017

(62,900)

(500)

352,688

(172,525)

—

180,163

(88,275)

(200)

39.96

45.74

44.00

43.61

n/a

44.38

44.33

41.15

91,688

44.43

2.7

0.5

n/a

2.3

2.0

n/a

2.8

1.8

n/a

1.4

During 2017, cash of $3.9 million was received for stock 
options exercised and $0.5 million related tax expense was 
recognized. The weighted-average remaining life of options 
exercisable and outstanding at December 31, 2017 was 
2.47 years.

Employee Stock Purchase Plan
The ESPP allows employees to purchase common stock at 
85% of the closing price on the trading day immediately 
preceding the initial offering date, which is set annually. 
Each eligible employee may purchase up to $21,199 worth 
of stock through payroll deductions over a period defined by 
the Board of Directors, which is currently a 12-month period, 
with shares issued at the end of the 12-month subscription 
period.

Stock-Based Compensation Expense
Stock-based compensation expense is recognized as 
operations and maintenance expense or is capitalized as 
part of construction overhead. The following table 
summarizes the financial statement impact of stock-based 
compensation under our LTIP, Restated SOP and ESPP:

In thousands

2017

2016

2015

Operations and maintenance
expense, for stock-based
compensation

$ 2,354 $ 2,370 $ 2,673

Income tax benefit

(930)

(924)

(1,012)

Net stock-based compensation
effect on net income (loss)

$ 1,424 $ 1,446 $ 1,661

Amounts capitalized for stock-based
compensation

$

528 $

554 $

661

7. DEBT

Short-Term Debt
Our primary source of short-term funds is from the sale of 
commercial paper and bank loans. In addition to issuing 
commercial paper or bank loans to meet seasonal working 
capital requirements, short-term debt is used temporarily to 
fund capital requirements. Commercial paper and bank 
loans are periodically refinanced through the sale of long-
term debt or equity securities. Our commercial paper 
program is supported by one or more committed credit
facilities. 

At December 31, 2017 and 2016, total short-term debt 
outstanding was $54.2 million and $53.3 million, 
respectively, which was comprised entirely of commercial 
paper. The weighted average interest rate at December 31, 
2017 and 2016 was 1.9% and 0.8%, respectively. 

The carrying cost of our commercial paper approximates fair 
value using Level 2 inputs, due to the short-term nature of 
the notes. See Note 2 for a description of the fair value 
hierarchy. At December 31, 2017, our commercial paper had 
a maximum remaining maturity of 11 days and an average 
remaining maturity of 6 days. 

We have a $300.0 million credit agreement, with a feature 
that allows us to request increases in the total commitment 
amount up to a maximum amount of $450.0 million. The 
maturity of the agreement is December 20, 2019. We have 
a letter of credit of $100.0 million. Any principal and unpaid 
interest owed on borrowings under the agreement is due 
and payable on or before the expiration date. There were no 
outstanding balances under the agreement and no letters of 
credit issued or outstanding at December 31, 2017 and 
2016.

The credit agreement requires that we maintain credit 
ratings with Standard & Poor’s (S&P) and Moody’s Investors 
Service, Inc. (Moody’s) and notify the lenders of any change 
in our senior unsecured debt ratings or senior secured debt 
ratings, as applicable, by such rating agencies. A change in 
our debt ratings is not an event of default, nor is the 
maintenance of a specific minimum level of debt rating a 
condition of drawing upon the credit facility. However, 
interest rates on any loans outstanding under the credit 
facility are tied to debt ratings, which would increase or 
decrease the cost of any loans under the credit facility when 
ratings are changed.

The credit agreement also requires us to maintain a 
consolidated indebtedness to total capitalization ratio of 
70% or less. Failure to comply with this covenant would 
entitle the lenders to terminate their lending commitments 
and accelerate the maturity of all amounts outstanding. We 
were in compliance with this covenant at December 31, 
2017 and 2016.

Long-Term Debt
The issuance of FMBs, which includes our medium-term 
notes, under the Mortgage and Deed of Trust (Mortgage) is 
limited by eligible property, adjusted net earnings, and other 
provisions of the Mortgage. The Mortgage constitutes a first 
mortgage lien on substantially all of our utility property. 

72

 
 
 
Maturities and Outstanding Long-Term Debt
Retirement of long-term debt for each of the 12-month 
periods through December 31, 2022 and thereafter are as 
follows: 

In thousands

Year

2018

2019

2020

2021

2022

$

97,000

30,000

75,000

60,000

—

Fair Value of Long-Term Debt
Our outstanding debt does not trade in active markets. We 
estimate the fair value of our debt using utility companies 
with similar credit ratings, terms, and remaining maturities to 
our debt that actively trade in public markets. These 
valuations are based on Level 2 inputs as defined in the fair 
value hierarchy. See Note 2. 

The following table provides an estimate of the fair value of 
our long-term debt, including current maturities of long-term 
debt, using market prices in effect on the valuation date:

Thereafter

524,700

In thousands

The following table presents our debt outstanding as of 
December 31:

In thousands

First Mortgage Bonds

2017

2016

Gross long-term debt

Unamortized debt
issuance costs

Carrying amount

Estimated fair value

$

$

$

December 31,

2017

2016

786,700

$

726,700

(6,813)

779,887

853,339

$

$

(7,377)

719,323

793,339

8. PENSION AND OTHER POSTRETIREMENT 
BENEFIT COSTS 

We maintain a qualified non-contributory defined benefit 
pension plan, non-qualified supplemental pension plans for 
eligible executive officers and other key employees, and 
other postretirement employee benefit plans. We also have 
a qualified defined contribution plan (Retirement K Savings 
Plan) for all eligible employees. The qualified defined benefit 
pension plan and Retirement K Savings Plan have plan 
assets, which are held in qualified trusts to fund retirement 
benefits. 

Effective January 1, 2007 and 2010, the qualified defined 
benefit pension plans and postretirement benefits for non-
union employees and union employees, respectively, were 
closed to new participants. 

These plans were not available to employees of our non-
utility subsidiaries. Non-union and union employees hired or 
re-hired after December 31, 2006 and 2009, respectively, 
and employees of NW Natural subsidiaries are provided an 
enhanced Retirement K Savings Plan benefit. 

Effective December 31, 2012, the qualified defined benefit 
pension plans for non-union and union employees were 
merged into a single plan.

7.000 % Series B due 2017
1.545 % Series B due 2018
6.600 % Series B due 2018
8.310 % Series B due 2019
7.630 % Series B due 2019
5.370 % Series B due 2020
9.050 % Series A due 2021
3.176 % Series B due 2021
3.542 % Series B due 2023
5.620 % Series B due 2023
7.720 % Series B due 2025
6.520 % Series B due 2025
7.050 % Series B due 2026
3.211 % Series B due 2026
7.000 % Series B due 2027
2.822 % Series B due 2027
6.650 % Series B due 2027
6.650 % Series B due 2028
7.740 % Series B due 2030
7.850 % Series B due 2030
5.820 % Series B due 2032
5.660 % Series B due 2033
5.250 % Series B due 2035
4.000 % Series B due 2042
4.136 % Series B due 2046
3.685 % Series B due 2047

Less: Current maturities

$

— $

75,000
22,000
10,000
20,000
75,000
10,000
50,000
50,000
40,000
20,000
10,000
20,000
35,000
20,000
25,000
19,700
10,000
20,000
10,000
30,000
40,000
10,000
50,000
40,000
75,000
786,700

97,000

40,000
75,000
22,000
10,000
20,000
75,000
10,000
50,000
50,000
40,000
20,000
10,000
20,000
35,000
20,000
—
19,700
10,000
20,000
10,000
30,000
40,000
10,000
50,000
40,000
—
726,700

40,000

Total long-term debt

$ 689,700

$ 686,700

First Mortgage Bonds
We issued $100.0 million of FMBs in September 2017 
consisting of $25.0 million with a coupon rate of 2.822% and 
maturity date in 2027 and $75 million with a coupon rate of 
3.685% and maturity date in 2047. 

Retirements of Long-Term Debt
We redeemed $40.0 million of FMBs with a coupon rate of 
7.000% in August 2017. 

73

 
The following table provides a reconciliation of the changes in benefit obligations and fair value of plan assets, as applicable, for 
the pension and other postretirement benefit plans, excluding the Retirement K Savings Plan, and a summary of the funded 
status and amounts recognized in the consolidated balance sheets as of December 31:

In thousands

Reconciliation of change in benefit obligation:

Obligation at January 1

Service cost

Interest cost

Net actuarial (gain) loss
Benefits paid(1)

Obligation at December 31

Reconciliation of change in plan assets:

Fair value of plan assets at January 1

Actual return on plan assets

Employer contributions
Benefits paid(1)

Fair value of plan assets at December 31

Funded status at December 31

Postretirement Benefit Plans

Pension Benefits

Other Benefits

2017

2016

2017

2016

$

457,839

$

445,628

$

29,395

$

31,049

7,090

18,111

34,829

7,083

18,399

7,688

(31,580)

(20,959)

341

1,141

(213)

(1,737)

391

1,175

(1,488)

(1,732)

$

486,289

$

457,839

$

28,927

$

29,395

$

257,714

$

249,338

$

40,308

21,483

12,593

16,742

(31,580)

(20,959)

— $

—

1,737

(1,737)

287,925

$

257,714

$

— $

—

—

1,732

(1,732)

—

(198,364) $

(200,125) $

(28,927) $

(29,395)

$

$

(1)  

In 2017, we completed a partial buy-out of our qualified defined benefit pension plan in which $9.3 million of plan assets and $8.7 million 
liabilities were transferred to an insurer to provide annuities for buy-out plan participants. 

Our qualified defined benefit pension plan has an aggregate benefit obligation of $449.7 million and $423.5 million at December 
31, 2017 and 2016, respectively, and fair values of plan assets of $287.9 million and $257.7 million, respectively. The following 
table presents amounts realized through regulatory assets or in other comprehensive loss (income) for the years ended 
December 31:

Regulatory Assets

Other Comprehensive Loss (Income)

Pension Benefits

Other Postretirement Benefits

Pension Benefits

In thousands

2017

2016

2015

2017

2016

2015

2017

2016

2015

Net actuarial loss (gain)

$ 12,177

$ 14,005

$

419

$

(214) $ (1,488) $

2,724

$

2,777

$

(1,196) $

(2,549)

Settlement Loss

Amortization of:

Prior service cost

Actuarial loss

—

—

—

—

—

—

(127)

(230)

(230)

(14,802)

(13,238)

(16,372)

468

(696)

468

(705)

(197)

(554)

—

—

(946)

193

—

1,386

—

—

(2,236)

Total

$ (2,752) $

537

$ (16,183) $

(442) $ (1,725) $

1,973

$

1,831

$

383

$

(4,785)

The following table presents amounts recognized in regulatory assets and accumulated other comprehensive loss (AOCL) at 
December 31:

In thousands

Prior service cost (credit)

Net actuarial loss

Total

Regulatory Assets

AOCL

Pension Benefits

Other Postretirement Benefits

Pension Benefits

2017

2016

2017

2016

2017

2016

$

$

49

$

176

$

(2,206) $

(2,675) $

— $

175,035

177,660

6,964

7,874

13,266

175,084

$

177,836

$

4,758

$

5,199

$

13,266

$

1

11,434

11,435

74

The following table presents amounts recognized in AOCL and the changes in AOCL related to our non-qualified employee 
benefit plans:

In thousands

Beginning balance

Amounts reclassified to AOCL

Amounts reclassified from AOCL:

Amortization of actuarial losses

Loss from plan settlement

Total reclassifications before tax

Tax expense (benefit)

Total reclassifications for the period

Ending balance

In 2018, an estimated $17.3 million will be amortized from 
regulatory assets to net periodic benefit costs, consisting of 
$17.7 million of actuarial losses, and $0.4 million of prior 
service credits. A total of $0.8 million will be amortized from 
AOCL to earnings related to actuarial losses in 2018.

Our assumed discount rate for the pension plan and other 
postretirement benefit plans was determined independently 
based on the Citigroup Above Median Curve (discount rate 
curve), which uses high quality corporate bonds rated AA- or 
higher by S&P or Aa3 or higher by Moody’s. The discount 
rate curve was applied to match the estimated cash flows in 
each of our plans to reflect the timing and amount of 
expected future benefit payments for these plans.

Our assumed expected long-term rate of return on plan 
assets for the qualified pension plan was developed using a 
weighted-average of the expected returns for the target 
asset portfolio. In developing the expected long-term rate of 
return assumption, consideration was given to the historical 
performance of each asset class in which the plan’s assets 
are invested and the target asset allocation for plan assets.

Our investment strategy and policies for qualified pension 
plan assets held in the retirement trust fund were approved 
by our Retirement Committee, which is composed of senior 
management with the assistance of an outside investment 
consultant. The policies set forth the guidelines and 
objectives governing the investment of plan assets. Plan 
assets are invested for total return with appropriate 
consideration for liquidity, portfolio risk, and return 
expectations. All investments are expected to satisfy the 
prudent investments rule under the Employee Retirement 
Income Security Act of 1974. The approved asset classes 
may include cash and short-term investments, fixed income, 
common stock and convertible securities, absolute and real 
return strategies, real estate, and investments in NW 
Natural securities. Plan assets may be invested in 
separately managed accounts or in commingled or mutual 
funds. Investment re-balancing takes place periodically as 
needed, or when significant cash flows occur, in order to 
maintain the allocation of assets within the stated target 
ranges. The retirement trust fund is not currently invested in 

Year Ended December 31,

2017

2016

(6,951) $

(2,794)

946

—

(1,848)

361

(1,487)

(8,438) $

(7,162)

(1,196)

1,386

193

383

(172)

211

(6,951)

$

$

NW Natural securities.

The following table presents the pension plan asset target 
allocation at December 31, 2017:

Asset Category

U.S. large cap equity

U.S. small/mid cap equity

Non-U.S. equity

Emerging markets equity

Long government/credit

High yield bonds

Emerging market debt

Real estate funds

 Target Allocation

29.3%

6.9

28.0

11.8

17.5

2.0

3.5

1.0

Our non-qualified supplemental defined benefit plan 
obligations were $36.6 million and $34.3 million at 
December 31, 2017 and 2016, respectively. These plans are 
not subject to regulatory deferral, and the changes in 
actuarial gains and losses, prior service costs, and transition 
assets or obligations are recognized in AOCL, net of tax 
until they are amortized as a component of net periodic 
benefit cost. These are unfunded, non-qualified plans with 
no plan assets; however, we indirectly fund a significant 
portion of our obligations with company and trust-owned life 
insurance and other assets.

Our other postretirement benefit plans are unfunded plans 
but are subject to regulatory deferral. The actuarial gains 
and losses, prior service costs, and transition assets or 
obligations for these plans are recognized as a regulatory 
asset. 

Net periodic benefit costs consist of service costs, interest 
costs, the amortization of actuarial gains and losses, and
the expected returns on plan assets, which are based in part 
on a market-related valuation of assets. The market-related 
valuation reflects differences between expected returns and 
actual investment returns with the differences recognized 
over a three-year or less period from the year in which they 
occur, thereby reducing year-to-year net periodic benefit 
cost volatility.

75

 
 
 
The following table provides the components of net periodic benefit cost for our pension and other postretirement benefit plans 
for the years ended December 31: 

In thousands

Service cost

Interest cost

Expected return on plan assets

Amortization of prior service costs

Amortization of net actuarial loss

Settlement expense

Net periodic benefit cost

Amount allocated to construction
Amount deferred to regulatory balancing account(1)

Pension Benefits

Other Postretirement Benefits

2017

2016

2015

2017

2016

2015

$

7,090

$

7,083

$

8,267

$

341

$

391

$

18,111

(20,433)

127

15,748

—

20,643

(6,597)

(6,542)

18,399

18,360

1,141

1,175

(20,054)

(20,676)

231

14,624

193

20,476

(5,746)

(6,252)

231

18,609

—

24,791

(6,834)

(8,241)

—

(468)

696

—

1,710

(587)

—

—

(468)

705

—

1,803

(600)

—

527

1,179

—

197

554

—

2,457

(808)

—

Net amount charged to expense

$

7,504

$

8,478

$

9,716

$

1,123

$

1,203

$

1,649

(1)   The deferral of defined benefit pension plan expenses above or below the amount set in rates was approved by the OPUC, with recovery of 
these deferred amounts through the implementation of a balancing account. The balancing account includes the expectation of higher net 
periodic benefit costs than costs recovered in rates in the near-term with lower net periodic benefit costs than costs recovered in rates 
expected in future years. Deferred pension expense balances include accrued interest at the utility’s authorized rate of return, with the 
equity portion of the interest recognized when amounts are collected in rates.

Net periodic benefit costs are reduced by amounts 
capitalized to utility plant based on approximately 25% to 
35% payroll overhead charge. In addition, a certain amount 
of net periodic benefit costs are recorded to the regulatory 
balancing account for pensions. 

Net periodic pension cost less amounts charged to capital 
accounts and regulatory balancing accounts are expenses 
recognized in earnings.

The following table provides the assumptions used in measuring periodic benefit costs and benefit obligations for the years 
ended December 31:

Pension Benefits

Other Postretirement Benefits

2017

2016

2015

2017

2016

2015

Assumptions for net periodic benefit cost:

Weighted-average discount rate

3.99%

4.17%

3.82%

3.85%

4.00%

3.74%

Rate of increase in compensation

3.25-4.5%

3.25-4.5%

3.25-5.0%

Expected long-term rate of return

7.50%

7.50%

7.50%

n/a

n/a

n/a

n/a

n/a

n/a

Assumptions for year-end funded status:

Weighted-average discount rate

3.52%

4.00%

4.21%

3.44%

3.85%

4.00%

Rate of increase in compensation

3.25-4.5%

3.25-4.5%

3.25-4.5%

Expected long-term rate of return

7.50%

7.50%

7.50%

n/a

n/a

n/a

n/a

n/a

n/a

The assumed annual increase in health care cost trend 
rates used in measuring other postretirement benefits as of 
December 31, 2017 was 7.50%. These trend rates apply to 
both medical and prescription drugs. Medical costs and 
prescription drugs are assumed to decrease gradually each 
year to a rate of 4.75% by 2026.

Assumed health care cost trend rates can have a significant 
effect on the amounts reported for the health care plans; 
however, other postretirement benefit plans have a cap on 
the amount of costs reimbursable by us. 

A one percentage point change in assumed health care cost 
trend rates would have the following effects:

In thousands

1% Increase

1% Decrease

Effect on net periodic
postretirement health care
benefit cost

Effect on the accumulated
postretirement benefit obligation

$

44

$

(39)

478

(428)

We review mortality assumptions annually and will update 
for material changes as necessary. In 2017, our mortality 
rate assumptions were updated from RP-2006 mortality 
tables for employees and healthy annuitants with a fully 
generational projection using scale MP-2016 to 
corresponding RP-2006 mortality tables using scale 
MP-2017, which partially offset increases of our projected 
benefit obligation. 

76

 
 
 
 
 
 
 
 
The following table provides information regarding employer 
contributions and benefit payments for the qualified pension 
plan, non-qualified pension plans, and other postretirement 
benefit plans for the years ended December 31, and 
estimated future contributions and payments:

In thousands

Pension Benefits

Other Benefits

$

16,742

$

Employer Contributions:

2016

2017

2018 (estimated)

Benefit Payments:

2015

2016

2017

Estimated Future Benefit Payments:

2018

2019

2020

2021

2022

2023-2027

21,483

17,710

35,923

20,959

31,580

22,679

23,546

24,542

25,471

26,095

145,065

1,732

1,737

1,835

2,018

1,732

1,737

1,835

1,871

1,861

1,904

1,886

9,261

Employer Contributions to Company-Sponsored 
Defined Benefit Pension Plans
We make contributions to our qualified defined benefit 
pension plans based on actuarial assumptions and 
estimates, tax regulations, and funding requirements under 
federal law. The Pension Protection Act of 2006 (the Act) 
established funding requirements for defined benefit plans. 
The Act establishes a 100% funding target over seven years 
for plan years beginning after December 31, 2008. In 2012 
the Moving Ahead for Progress in the 21st Century Act 
(MAP-21) legislation changed several provisions affecting 
pension plans, including temporary funding relief and 
Pension Benefit Guaranty Corporation (PBGC) premium 
increases, which reduces the level of minimum required 
contributions in the near-term but generally increases 
contributions in the long-run and increases the operational 
costs of running a pension plan. In 2014, the Highway and 
Transportation Funding Act (HATFA) was signed and 
extends certain aspects of MAP-21 as well as modifies the 
phase-out periods for the limitations.  

Our qualified defined benefit pension plan is currently 
underfunded by $161.7 million at December 31, 2017. 
Including the impacts of MAP-21 and HATFA, we made 
cash contributions totaling $19.4 million to our qualified 
defined benefit pension plan for 2017. During 2018, we 
expect to make contributions of approximately $15.5 million 
to this plan.

Multiemployer Pension Plan
In addition to the Company-sponsored defined benefit plans 
presented above, prior to 2014 we contributed to a 
multiemployer pension plan for our utility's union employees 
known as the Western States Office and Professional 
Employees International Union Pension Fund (Western 
States Plan). The plan's employer identification number is 
94-6076144. Effective December 22, 2013, we withdrew 

77

from the plan, which was a noncash transaction. Vested 
participants will receive all benefits accrued through the date 
of withdrawal. As the plan was underfunded at the time of 
withdrawal, we were assessed a withdrawal liability of $8.3 
million, plus interest, which requires NW Natural to pay $0.6 
million each year to the plan for 20 years beginning in July 
2014. The cost of the withdrawal liability was deferred to a 
regulatory account on the balance sheet. 

We made payments of $0.6 million for 2017, and as of 
December 31, 2017 the liability balance was $7.1 million. 
For 2016 and 2015, contributions to the plan were $0.6 
million and $0.6 million, respectively, which was 
approximately 4% to 5% of the total contributions to the plan 
by all employer participants in those years.

Defined Contribution Plan
The Retirement K Savings Plan is a qualified defined 
contribution plan under Internal Revenue Code Sections 
401(a) and 401(k). Employer contributions totaled $5.4 
million, $4.6 million, and $3.7 million for 2017, 2016, and 
2015, respectively. The Retirement K Savings Plan includes 
an Employee Stock Ownership Plan. 

Deferred Compensation Plans
The supplemental deferred compensation plans for eligible 
officers and senior managers are non-qualified plans. These 
plans are designed to enhance the retirement savings of 
employees and to assist them in strengthening their 
financial security by providing an incentive to save and 
invest regularly. 

Fair Value
Below is a description of the valuation methodologies used 
for assets measured at fair value. In cases where the 
pension plan is invested through a collective trust fund or 
mutual fund, the fund's market value is utilized. Market 
values for investments directly owned are also utilized.

U.S. LARGE CAP EQUITY and U.S. SMALL/MID CAP 
EQUITY. These are Level 1 and non-published net asset 
value (NAV) assets. The Level 1 assets consist of directly 
held stocks and mutual funds with a readily determinable 
fair value, including a published NAV. The non-published 
NAV assets consist of commingled trusts where NAV is not 
published but the investment can be readily disposed of at 
NAV or market value. Directly held stocks are valued at the 
closing price reported in the active market on which the 
individual security is traded. Mutual funds and commingled 
trusts are valued at NAV and the unit price, respectively. 
This asset class includes investments primarily in U.S. 
common stocks.

NON-U.S. EQUITY. These are Level 1 and non-published NAV 
assets. The Level 1 assets consist of directly held stocks, 
and the non-published NAV assets consist of commingled 
trusts where the NAV/unit price is not published but the 
investment can be readily disposed of at the NAV/unit price. 
Directly held stocks are valued at the closing price reported 
in the active market on which the individual security is 
traded, and the commingled trusts are valued at unit price. 
This asset class includes investments primarily in foreign 
equity common stocks.

 
 
 
 
  
EMERGING MARKETS EQUITY. These are non-published 
NAV assets consisting of an open-end mutual fund where 
the NAV price is not published but the investment can be 
readily disposed of at the NAV, and a commingled trust 
where the investment can be readily disposed of at unit 
price. This asset class includes investments primarily in 
common stocks in emerging markets.

FIXED INCOME. These are non-published NAV assets 
consisting of a commingled trust, valued at unit price, where 
unit price is not published, but the investment can be readily 
disposed of at the unit price. This asset class includes 
investments primarily in investment grade debt and fixed 
income securities.

LONG GOVERNMENT/CREDIT. These are non-published NAV 
and Level 2 assets. The non-published NAV assets include 
commingled trusts, valued at unit price, where unit price is 
not published, but the investment can be readily disposed of 
at the unit price. The Level 2 assets consist of directly held 
fixed-income securities, with readily determinable fair 
values, whose values are determined by closing prices if 
available and by matrix prices for illiquid securities. This 
asset class includes long duration fixed income investments 
primarily in U.S. treasuries, U.S. government agencies, 
municipal securities, mortgage-backed securities, asset-
backed securities, as well as U.S. and international 
investment-grade corporate bonds.

HIGH YIELD BONDS. These are non-published NAV assets, 
consisting of a limited partnership and a commingled trust 
where the valuation is not published but the investment can 
be readily disposed of at market value, valued at NAV or 
unit price, respectively. This asset class includes 
investments primarily in high yield bonds.

EMERGING MARKET DEBT. This is a non-published NAV 
asset consisting of a commingled trust with a readily 
determinable fair value, where unit price is not published, 
but the investment can be readily disposed of at the unit 
price. This asset class includes investments primarily in 
emerging market debt. 

REAL ESTATE. These are Level 1 and non-published NAV 
assets. The Level 1 asset is a mutual fund with a readily 
determinable fair value, including a published NAV. The non-
published NAV asset is a commingled trust with a readily 
determinable fair value, where unit price is not published, 
but the investment can be readily disposed of at the unit 
price. This asset class includes investments primarily in real 
estate investment trust (REIT) equity securities globally. 

ABSOLUTE RETURN STRATEGY. This is a non-published 
NAV asset consisting of a hedge fund of funds where the 
valuation is not published. This hedge fund of funds is 
winding down. Based on recent dispositions, we believe the 
remaining investment is fairly valued. The hedge fund of 
funds is valued at the weighted average value of 
investments in various hedge funds, which in turn are 
valued at the closing price of the underlying securities. This 
asset class primarily includes investments in common 
stocks and fixed income securities. 

CASH AND CASH EQUIVALENTS. These are Level 1 and non-
published NAV assets. The Level 1 assets consist of cash in 
U.S. dollars, which can be readily disposed of at face value. 
The non-published NAV assets represent mutual funds 
without published NAV's but the investment can be readily 
disposed of at the NAV. The mutual funds are valued at the 
NAV of the shares held by the plan at the valuation date. 

The preceding valuation methods may produce a fair value 
calculation that is not indicative of net realizable value or 
reflective of future fair values. Although we believe these 
valuation methods are appropriate and consistent with other 
market participants, the use of different methodologies or 
assumptions to determine the fair value of certain 
investments could result in a different fair value 
measurement at the reporting date.

Investment securities are exposed to various financial risks 
including interest rate, market, and credit risks. Due to the 
level of risk associated with certain investment securities, it 
is reasonably possible that changes in the values of our 
investment securities will occur in the near term and such 
changes could materially affect our investment account 
balances and the amounts reported as plan assets available 
for benefit payments.

78

  
The following table presents the fair value of plan assets, including outstanding receivables and liabilities, of the retirement trust 
fund:

In thousands

Investments

U.S. large cap equity

U.S. small/mid cap equity

Non-U.S. equity

Emerging markets equity

Fixed income

Long government/credit

High yield bonds

Emerging market debt

Real estate

Absolute return strategy

Cash and cash equivalents

Total investments

Investments

U.S. large cap equity

U.S. small/mid cap equity

Non-U.S. equity

Emerging markets equity

Fixed income

Long government/credit

High yield bonds

Emerging market debt

Real estate

Absolute return strategy

Cash and cash equivalents

Total investments

Receivables:

Accrued interest and dividend income

Due from broker for securities sold

Total receivables

Liabilities:

Due to broker for securities purchased

December 31, 2017

Level 1

Level 2

Level 3

Non-Published 
NAV(1)

Total

$

— $

—

21,211

—

—

—

—

—

—

—

82

— $

— $

102,851

$

102,851

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

16,423

56,075

28,743

2,781

33,081

2,777

12,605

5,544

189

5,533

16,423

77,286

28,743

2,781

33,081

2,777

12,605

5,544

189

5,615

$

21,293

$

— $

— $

266,602

$

287,895

December 31, 2016

Level 1

Level 2

Level 3

Non-Published 
NAV(1)

Total

$

49,841

$

— $

— $

5,655

$

18,629

22,404

—

—

—

—

—

17,857

—

9

108,740

$

$

—

—

—

—

34,955

—

—

—

—

—

—

—

—

—

—

—

—

—

$

$

— $

34,955

$

— $

— $

10,232

25,346

13,457

6,719

17,960

14,072

8,504

882

3,111

2,482

108,420

$

$

55,496

28,861

47,750

13,457

6,719

52,915

14,072

8,504

18,739

3,111

2,491

252,115

December 31,

2017

2016

    $

    $

    $

30

—

30

$

$

451

5,170

5,621

— $

22

Total investment in retirement trust

257,714
(1)  The fair value for these investments is determined using Net Asset Value per share (NAV) as of December 31, as a practical expedient, and 

287,925

    $

$

therefore they are not classified within the fair value hierarchy. These investments primarily consist of institutional investment products, for 
which the NAV is generally not publicly available.

79

 
 
 
   
 
   
 
 
   
 
 
   
 
 
 9. INCOME TAX

The following table provides a reconciliation between 
income taxes calculated at the statutory federal tax rate and 
the provision for income taxes reflected in the consolidated 
statements of comprehensive income or loss for December 
31:

Dollars in thousands

2017

2016

2015

Income taxes (benefits) at
federal statutory rate

Increase (decrease):

State income tax, net of
federal

Amortization of
investment tax credits

Differences required to be
flowed-through by
regulatory commissions

Gains on company and
trust-owned life insurance

Effect of TCJA

Deferred Tax Rate
Differential Post-TCJA

Other, net

Total provision for income
taxes (benefits)

$(30,233)

$ 34,863

$ 31,310

(5,784)

4,582

4,195

(4)

(41)

(118)

2,357

2,357

2,357

(872)

(594)

(766)

(21,429)

26,947

(1,739)

—

—

—

—

(453)

(1,225)

$(30,757)

$ 40,714

$ 35,753

Effective tax rate

35.6%

40.9%

40.0%

The effective income tax rate for 2017 compared to 2016 
changed primarily as a result of the TCJA, the equity portion 
of AFUDC and excess tax benefits related to stock-based 
compensation. The effective income tax rate increase from 
2016 compared to 2015 was primarily the result of lower 
depletion deductions from gas reserves activity in 2016.

The provision for current and deferred income taxes 
consists of the following at December 31:

In thousands

Current

   Federal

   State

Deferred

   Federal

   State

2017

2016

2015

$ 16,403

$

7,402

$ 10,558

4,892

21,295

2,042

9,444

(41,134)

26,219

(10,918)

5,051

(52,052)

31,270

61

10,619

18,729

6,405

25,134

Total provision for income
taxes (loss benefits)

$ (30,757) $ 40,714

$ 35,753

At December 31, 2017 and 2016, regulatory income tax 
assets of $21.3 million and $43.0 million, respectively, were 
recorded, a portion of which is recorded in current assets. 
These regulatory income tax assets primarily represent 
future rate recovery of deferred tax liabilities, resulting from 
differences in utility plant financial statement and tax bases 
and utility plant removal costs, which were previously flowed 
through for rate making purposes and to take into account 
the additional future taxes, which will be generated by that 
recovery. These deferred tax liabilities, and the associated 
regulatory income tax assets, are currently being recovered 

80

through customer rates. At December 31, 2017, we had a 
regulatory income tax asset of $0.9 million representing 
probable future rate recovery of deferred tax liabilities 
resulting from the equity portion of AFUDC.

The following table summarizes the total provision (benefit) 
for income taxes for the utility and non-utility business 
segments for December 31:

In thousands

Utility:

   Current

   Deferred

Deferred investment tax
credits

Non-utility business segments:

   Current

   Deferred

2017

2016

2015

$ 21,453

$ 10,300

$ 15,890

19,479

28,749

20,834

(4)

(41)

(118)

40,928

39,008

36,606

(158)

(856)

(5,271)

(71,527)

(71,685)

2,562

1,706

4,418

(853)

Total provision for income taxes

$(30,757) $ 40,714

$ 35,753

The following table summarizes the tax effect of significant 
items comprising our deferred income tax accounts at 
December 31:

In thousands

Deferred tax liabilities:

   Plant and property

   Regulatory income tax assets

   Regulatory liabilities

   Non-regulated deferred tax liabilities

      Total

Deferred tax assets:

2017

2016

$ 296,114

$ 428,642

22,209

29,114

933

43,048

48,291

51,446

$ 348,370

$ 571,427

Regulatory income tax liabilities

$ 56,470

$

Non-regulated deferred tax assets

17,796

—

—

Pension and postretirement
obligations

Alternative minimum tax credit
carryforward

      Total

3,512

4,493

66

9,853

$ 77,844

$ 14,346

Deferred income tax liabilities, net

$ 270,526

$ 557,081

Deferred investment tax credits

—

4

Deferred income taxes and investment
tax credits

$ 270,526

$ 557,085

Management assesses the available positive and negative 
evidence to estimate if sufficient taxable income will be 
generated to utilize the existing deferred tax assets. Based 
upon this assessment, we have determined we are more 
likely than not to realize all deferred tax assets recorded as 
of December 31, 2017.

As a result of certain realization requirements prescribed in 
the accounting guidance for income taxes, the tax benefit of 
statutory depletion is recognized no earlier than the year in 
which the depletion is deductible on our federal income tax 
return. Income tax expense decreased by $0.9 million in 
2015 as a result of realizing deferred depletion benefit from 
2013 and 2014. This benefit is included in Other, net in the 
statutory rate reconciliation table.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Uncertain tax positions are accounted for in accordance with 
accounting standards that require management’s 
assessment of the anticipated settlement outcome of 
material uncertain tax positions taken in a prior year, or 
planned to be taken in the current year. Until such positions 
are sustained, we would not recognize the uncertain tax 
benefits resulting from such positions. No reserves for 
uncertain tax positions were recorded as of December 31, 
2017, 2016, or 2015.

Our federal income tax returns for tax years 2013 and 
earlier are closed by statute. The IRS Compliance 
Assurance Process (CAP) examination of the 2013, 2014, 
and 2015 tax years have been completed. There were no 
material changes to these returns as filed. The 2016 and 
2017 tax years are currently under IRS CAP examination. 
Our 2018 CAP application has been accepted by the IRS. 
Under the CAP program, we work with the IRS to identify 
and resolve material tax matters before the tax return is filed 
each year. As of December 31, 2017, income tax years 
2014 through 2016 remain open for state examination. 

U.S. Federal TCJA Matters
On December 22, 2017, the TCJA was enacted and 
permanently lowers the U.S. federal corporate income tax 
rate to 21% from the existing maximum rate of 35%, 
effective for our tax year beginning January 1, 2018. The 
TCJA includes specific provisions related to regulated public 
utilities that provide for the continued deductibility of interest 
expense and the elimination of bonus depreciation for 
property acquired after September 27, 2017.

As a result of the reduction of the U.S. corporate income tax 
rate to 21%, U.S. GAAP requires deferred tax assets and 
liabilities be revalued as of the date of enactment, with 
resulting tax effects accounted for in the reporting period of 
enactment. We recorded a net revaluation of deferred tax 
asset and liability balances of $196.4 million as of 
December 31, 2017. This revaluation had no impact on our 
2017 cash flows.

The net change in our utility deferred taxes, that were 
determined to have previously been included in ratemaking 
activities by the OPUC and WUTC, was recorded as a net 
regulatory liability that is expected to accrue to the future 
benefit of customers. It is possible that this estimated 
regulatory liability balance of $213.3 million, which includes 
a gross up for income taxes of $56.5 million, may increase 
or decrease as a result of future regulatory guidance by the 
OPUC and WUTC or as additional authoritative 
interpretation of the TCJA becomes available.

The change in our utility deferred taxes of $18.2 million, 
associated with tax benefits that have previously been 
flowed through to customers or for the equity portion of 
AFUDC, resulted in an identical reduction in the associated 
regulatory assets. This change had no impact on our 
income tax expense. The net change in our utility deferred 
taxes, that were determined to have been previously 
excluded from ratemaking activities by the OPUC and 
WUTC, and the change in deferred taxes associated with 
the gas storage segment and other non-regulated 
operations, was recorded as a net reduction of income tax 
expense of $21.4 million.

Under pre-TCJA law, business interest is generally 
deductible in the determination of taxable income. The TCJA 
imposes a new limitation on the deductibility of net business 
interest expense in excess of approximately 30% of 
adjusted taxable income. Taxpayers operating in the trade 
or business of public regulated utilities are excluded from 
these new interest expense limitations. 

There is uncertainty whether the new interest expense 
limitation may apply to our non-regulated operations. The 
legislative history indicates that all members of a 
consolidated or affiliated group are treated as a single 
taxpayer with respect to applying business interest 
limitations. Future authoritative guidance may indicate that 
net interest expense must be allocated between regulated 
and non-regulated activities within the consolidated group. 
Until such time that additional guidance is available that 
eliminates this uncertainty, we are unable to estimate 
whether the new interest limitation rules will impact our 
future operating results. The new interest limitation rules are 
effective for taxable years beginning after December 31, 
2017. There is no grandfathering for debt instruments 
outstanding prior to such date. Net business interest 
expense amounts disallowed may be carried forward 
indefinitely and treated as interest in succeeding taxable 
years.

The TCJA generally provides for immediate full expensing 
for qualified property acquired and placed in service after 
September 27, 2017 and before January 1, 2023. This 
would generally provide for accelerated cost recovery for 
capital investments. However, the definition of qualified 
property excludes property used in the trade or business of 
a public regulated utility. The definition of utility trade or 
business is the same as that used by the TCJA with respect 
to the imposition of the net interest expense limitation 
discussed above. As a result, a similar uncertainty exists 
with respect to whether the exclusion from full expensing will 
apply to our full consolidated group, which primarily 
operates as a regulated public utility, or whether full 
expensing will be available to our non-regulated activities. 

An additional uncertainty exists with respect to whether 50% 
bonus depreciation, which was in effect prior to the TCJA, 
will apply to property for which a contract was entered into 
or significant construction had occurred prior to September 
27, 2017, but that was not placed in service until after that 
date. We excluded all assets placed in service by the 
consolidated group after September 27, 2017 from bonus 
depreciation. If future authoritative guidance indicates that 
bonus depreciation is available to us for these capital 
expenditures, this would primarily result in a decrease to our 
current income taxes payable and an increase in regulatory 
liability. 

The SEC staff issued Staff Accounting Bulletin 118, which 
provides guidance on accounting for the tax effects of the 
TCJA. SAB 118 provides a measurement period that should 
not extend beyond one year from the TCJA enactment date 
for companies to complete the accounting under ASC 740. 
To the extent that a company’s accounting for certain 
income tax effects of the TCJA is incomplete but it is able to 
determine a reasonable estimate, it must record a 
provisional estimate in the financial statements. Consistent 
with SAB 118, the determination to exclude all assets placed 

81

respectively. These accrued asset removal costs are 
reflected on the balance sheet as regulatory liabilities. See 
Note 2. During 2017 and 2016, we did not acquire any 
equipment under capital leases. 

11. GAS RESERVES

We have invested $188 million through our gas reserves 
program in the Jonah Field located in Wyoming as of 
December 31, 2017. Gas reserves are stated at cost, net of 
regulatory amortization, with the associated deferred tax 
benefits recorded as liabilities on the consolidated balance 
sheets. Our investment in gas reserves provides long-term 
price protection for utility customers through the original 
agreement with Encana Oil & Gas (USA) Inc. under which 
we invested $178 million and the amended agreement with 
Jonah Energy LLC under which an additional $10 million 
was invested.

We entered into our original agreements with Encana in 
2011 under which we hold working interests in certain 
sections of the Jonah Field. Gas produced in these sections 
is sold at prevailing market prices, and revenues from such 
sales, net of associated operating and production costs and 
amortization, are credited to the utility's cost of gas. The 
cost of gas, including a carrying cost for the rate base 
investment, is included in our annual Oregon PGA filing, 
which allows us to recover these costs through customer 
rates. Our investment under the original agreement, less 
accumulated amortization and deferred taxes, earns a rate 
of return. 

In March 2014, we amended the original gas reserves 
agreement in order to facilitate Encana's proposed sale of 
its interest in the Jonah field to Jonah Energy. Under the 
amendment, we ended the drilling program with Encana, 
but increased our working interests in our assigned 
sections of the Jonah field. We also retained the right to 
invest in new wells with Jonah Energy. Under the amended 
agreement we still have the option to invest in additional 
wells on a well-by-well basis with drilling costs and resulting 
gas volumes shared at our amended proportionate working 
interest for each well in which we invest. We elected to 
participate in some of the additional wells drilled in 2014, 
but have not had the opportunity to participate in additional 
wells since 2014. However, we may have the opportunity to 
participate in more wells in the future. 

Gas produced from the additional wells is included in our 
Oregon PGA at a fixed rate of $0.4725 per therm, which 
approximates the 10-year hedge rate plus financing costs 
at the inception of the investment. 

Gas reserves acted to hedge the cost of gas
for approximately 6%, 8% and 11% of our utility's gas 
supplies for the years ended December 31, 2017, 2016, 
and 2015 respectively. 

in service after September 27, 2017 from bonus 
depreciation is provisional.

We primarily operate in the States of Oregon and 
Washington. The extent to which a particular state adopts 
the U.S. Internal Revenue Code directly affects the 
application of the enacted federal changes of the TCJA to its 
taxable income computation. To varying degrees, Oregon 
and Washington corporate business tax approaches rely on 
federal income tax law, including the Internal Revenue Code 
and the associated Treasury regulations. It is possible that 
the federal changes resulting from the TCJA will cause 
states to reassess their future conformity, however, we have 
evaluated the state impacts of the TCJA under current law. 

Oregon automatically adopts changes to the U.S. Internal 
Revenue Code related to the calculation of consolidated 
corporate taxable income. By both State statute and 
administrative rule, Oregon corporation excise tax law, as 
related to the definition of taxable income, is tied to federal 
tax law as applicable to our tax year. Changes enacted to 
the definition of federal taxable income by the TCJA are 
effective for Oregon tax purposes in the same manner as for 
federal tax purposes. As a result, the net interest limitation 
and full expensing exclusions, discussed above, apply to 
Oregon as well. 

Washington State does not have a corporate income tax, 
but rather imposes a tax on our gross receipts. The TCJA 
does not include a change to the definition of gross receipts, 
or the timing of their recognition, that is currently anticipated 
to impact us. As a result, no change to Washington State 
reporting is anticipated.

10. PROPERTY, PLANT, AND EQUIPMENT

The following table sets forth the major classifications of our 
property, plant, and equipment and accumulated 
depreciation at December 31:

In thousands

2017

2016

Utility plant in service

$2,975,217

$2,843,243

Utility construction work in progress

Less: Accumulated depreciation

Utility plant, net

Non-utility plant in service

Non-utility construction work in
progress

Less: Accumulated depreciation

Non-utility plant, net

159,924

942,879

62,264

903,096

2,192,262

2,002,411

75,639

299,378

4,671

17,598

62,712

3,931

44,820

258,489

Total property, plant, and equipment

$2,254,974

$2,260,900

Capital expenditures in accrued
liabilities

$

34,976

$

9,547

The weighted average depreciation rate for utility assets 
was 2.8% for utility assets during 2017, 2016, and 2015. 
The weighted average depreciation rate for non-utility 
assets was 1.9% in 2017, 2.0% in 2016, and 2.2% in 2015.

Accumulated depreciation does not include the accumulated 
provision for asset removal costs of $360.9 million and 
$341.1 million at December 31, 2017 and 2016, 

82

The following table outlines our net gas reserves 
investment at December 31:

In thousands

2017

2016

Gas reserves, current

$

15,704

$

15,926

Gas reserves, non-current

171,832

171,610

Less: Accumulated amortization

Total gas reserves(1)

Less: Deferred taxes on gas reserves

87,779

99,757

22,712

71,426

116,110

28,119

Net investment in gas reserves

$

77,045

$

87,991

(1)   Our net investment in additional wells included in total gas 
reserves was $5.8 million and $6.7 million at December 31, 
2017 and 2016, respectively. 

Our investment is included in our consolidated balance 
sheets under gas reserves with our maximum loss 
exposure limited to our investment balance.

12. INVESTMENTS

Investments include financial investments in life insurance 
policies, and equity method investments in certain 
partnerships and limited liability companies. The following 
table summarizes our other investments at December 31:

In thousands

2017

2016

Investments in life insurance policies

$ 50,792

$ 52,719

Investments in gas pipeline

Other

13,669

13,767

1,902

1,890

   Total other investments

$ 66,363

$ 68,376

Investment in Life Insurance Policies
We have invested in key person life insurance contracts to 
provide an indirect funding vehicle for certain long-term 
employee and director benefit plan liabilities. The amount in 
the above table is reported at cash surrender value, net of 
policy loans.

Investments in Gas Pipeline
TWP, a wholly-owned subsidiary of TWH, is pursuing the 
development of a new gas transmission pipeline that would 
provide an interconnection with our utility distribution 
system. NWN Energy, a wholly-owned subsidiary of NW 
Natural, owns 50% of TWH, and 50% is owned by 
TransCanada American Investments Ltd., an indirect wholly-
owned subsidiary of TransCanada Corporation.  

Variable Interest Entity (VIE) Analysis
TWH is a VIE, with our investment in TWP reported under 
equity method accounting. We have determined we are not 
the primary beneficiary of TWH’s activities as we only have 
a 50% share of the entity, and there are no stipulations that 
allow us a disproportionate influence over it. Our 
investments in TWH and TWP are included in other 
investments on our balance sheet. If we do not develop this 
investment, then our maximum loss exposure related to 
TWH is limited to our equity investment balance, less our 
share of any cash or other assets available to us as a 50% 
owner. Our investment balance in TWH was $13.4 million at 
December 31, 2017 and 2016. 

Impairment Analysis
Our investments in nonconsolidated entities accounted for 
under the equity method are reviewed for impairment at 
each reporting period and following updates to our corporate 
planning assumptions. If it is determined a loss in value is 
other than temporary, a charge is recognized for the 
difference between the investment’s carrying value and its 
estimated fair value. Fair value is based on quoted market 
prices when available or on the present value of expected 
future cash flows. Differing assumptions could affect the 
timing and amount of a charge recorded in any period.

In 2011, TWP withdrew its original application with the 
FERC for a proposed natural gas pipeline in Oregon and 
informed FERC that it intended to re-file an application to 
reflect changes in the project scope aligning the project with 
the region’s current and future gas infrastructure needs. 
TWP continues working with customers in the Pacific 
Northwest to further understand their gas transportation 
needs and determine the commercial support for a revised 
pipeline proposal. A new FERC certificate application is 
expected to be filed to reflect a revised scope based on 
these regional needs.

Our equity investment was not impaired at December 31, 
2017 as the fair value of expected cash flows from planned 
development exceeded our remaining equity investment of 
$13.4 million at December 31, 2017. However, if we learn 
that the project is not viable or will not go forward, we could 
be required to recognize a maximum charge of up to 
approximately $13.4 million based on the current amount of 
our equity investment, net of cash and working capital at 
TWP. We will continue to monitor and update our 
impairment analysis as required.

13. DERIVATIVE INSTRUMENTS

We enter into financial derivative contracts to hedge a 
portion of our utility’s natural gas sales requirements. These 
contracts include swaps, options, and combinations of 
option contracts. We primarily use these derivative financial 
instruments to manage commodity price variability. A small 
portion of our derivative hedging strategy involves foreign 
currency exchange contracts. 

We enter into these financial derivatives, up to prescribed 
limits, primarily to hedge price variability related to our 
physical gas supply contracts as well as to hedge spot 
purchases of natural gas. The foreign currency forward 
contracts are used to hedge the fluctuation in foreign 
currency exchange rates for pipeline demand charges paid 
in Canadian dollars. 

In the normal course of business, we also enter into 
indexed-price physical forward natural gas commodity 
purchase contracts and options to meet the requirements of 
utility customers. These contracts qualify for regulatory 
deferral accounting treatment. 

We also enter into exchange contracts related to the third-
party asset management of our gas portfolio, some of which 
are derivatives that do not qualify for hedge accounting or 
regulatory deferral, but are subject to our regulatory sharing 
agreement. These derivatives are recognized in operating 

83

                                                                                    
revenues in our gas storage segment, net of amounts 
shared with utility customers. 

Notional Amounts
The following table presents the absolute notional amounts 
related to open positions on our derivative instruments:

In thousands

Natural gas (in therms):

Financial

Physical

Foreign exchange

At December 31,

2017

2016

429,100

477,430

520,268

535,450

$ 7,669

$ 7,497

Purchased Gas Adjustment (PGA)
Derivatives entered into by the utility for the procurement or
hedging of natural gas for future gas years generally receive 
regulatory deferral accounting treatment. In general, our 
commodity hedging for the current gas year is completed 
prior to the start of the gas year, and hedge prices are 
reflected in our weighted-average cost of gas in the PGA 
filing. Hedge contracts entered into after the start of the PGA 
period are subject to our PGA incentive sharing mechanism 
in Oregon. We entered the 2017-18 and 2016-17 gas year 
with our forecasted sales volumes hedged at 49% and 48% 
in financial swap and option contracts, and 26% and 27% in 
physical gas supplies, respectively. Hedge contracts entered 
into prior to our PGA filing, in September 2017, were 
included in the PGA for the 2017-18 gas year. Hedge 
contracts entered into after our PGA filing, and related to 
subsequent gas years, may be included in future PGA filings 
and qualify for regulatory deferral.

Unrealized and Realized Gain/Loss
The following table reflects the income statement presentation for the unrealized gains and losses from our derivative 
instruments: 

In thousands

Benefit (expense) to cost of gas

Operating revenues
 Amounts deferred to regulatory accounts on balance sheet

Total gain (loss) in pre-tax earnings

UNREALIZED GAIN/LOSS. Outstanding derivative 
instruments related to regulated utility operations are 
deferred in accordance with regulatory accounting 
standards. The cost of foreign currency forward and natural 
gas derivative contracts are recognized immediately in the 
cost of gas; however, costs above or below the amount 
embedded in the current year PGA are subject to a 
regulatory deferral tariff and therefore, are recorded as a 
regulatory asset or liability. 

REALIZED GAIN/LOSS. We realized net losses of $7.8 
million and $26.9 million for the years ended December 31, 
2017 and 2016, respectively, from the settlement of natural 
gas financial derivative contracts. Realized gains and losses 
are recorded in cost of gas, deferred through our regulatory 
accounts, and amortized through customer rates in the 
following year. 

Credit Risk Management of Financial Derivatives 
Instruments
No collateral was posted with or by our counterparties as of 
December 31, 2017 or 2016. We attempt to minimize the 
potential exposure to collateral calls by counterparties 
to manage our liquidity risk. Counterparties generally allow a 
certain credit limit threshold before requiring us to post 
collateral against loss positions. Given our counterparty 
credit limits and portfolio diversification, we were not subject 
to collateral calls in 2017 or 2016. Our collateral call 
exposure is set forth under credit support agreements, 
which generally contain credit limits. We could also be 
subject to collateral call exposure where we have agreed to 

December 31, 2017

December 31, 2016

Natural gas
commodity

Foreign
exchange

Natural gas
commodity

Foreign
exchange

$

$

(26,000) $

(1,021)

26,665

107
—

(107)

$

22,746

$

995

(23,394)

(356) $

— $

347

$

(130)
—

130

—

provide adequate assurance, which is not specific as to the 
amount of credit limit allowed, but could potentially require 
additional collateral in the event of a material adverse 
change. 

Based on current commodity financial swap and option 
contracts outstanding, which reflect unrealized losses of 
$22.3 million at December 31, 2017, we have estimated the 
level of collateral demands, with and without potential 
adequate assurance calls, using current gas prices and 
various credit downgrade rating scenarios for NW Natural as 
follows:

Credit Rating Downgrade Scenarios

(Current
Ratings) 
A+/A3

BBB+/
Baa1

BBB/
Baa2

BBB-/
Baa3

Specul-
ative

$

— $ — $ — $ (5,428) $(15,422)

—

—

— (5,428)

(11,594)

In thousands

With
Adequate
Assurance
Calls

Without
Adequate
Assurance
Calls

Our financial derivative instruments are subject to master 
netting arrangements; however, they are presented on a 
gross basis in our consolidated balance sheets. We and our 
counterparties have the ability to set-off obligations to each 
other under specified circumstances. Such circumstances 
may include a defaulting party, a credit change due to a 
merger affecting either party, or any other termination event.

84

If netted by counterparty, our derivative position would result 
in an asset of $2.9 million and a liability of $23.3 million as 
of December 31, 2017. As of December 31, 2016, our 
derivative position would have resulted in an asset of $18.8 
million and a liability of $0.7 million.

We are exposed to derivative credit and liquidity risk 
primarily through securing fixed price natural gas commodity 
swaps to hedge the risk of price increases for our natural 
gas purchases made on behalf of customers. We utilize 
master netting arrangements through International Swaps 
and Derivatives Association contracts to minimize this risk 
along with collateral support agreements with counterparties 
based on their credit ratings. In certain cases, we require 
guarantees or letters of credit from counterparties to meet 
our minimum credit requirement standards.

Our financial derivatives policy requires counterparties to 
have a certain investment-grade credit rating at the time the 
derivative instrument is entered into, and the policy specifies 
limits on the contract amount and duration based on each 
counterparty’s credit rating. We do not speculate with 
derivatives; instead, we use derivatives to hedge our 
exposure above risk tolerance limits. Any increase in market 
risk created by the use of derivatives should be offset by the 
exposures they modify.

We actively monitor our derivative credit exposure and place 
counterparties on hold for trading purposes or require other 
forms of credit assurance, such as letters of credit, cash 
collateral, or guarantees as circumstances warrant. Our 
ongoing assessment of counterparty credit risk includes 
consideration of credit ratings, credit default swap spreads, 
bond market credit spreads, financial condition, government 
actions, and market news. We use a Monte-Carlo simulation 
model to estimate the change in credit and liquidity risk from 
the volatility of natural gas prices. The results of the model 
are used to establish earnings-at-risk trading limits. Our 
credit risk for all outstanding financial derivatives at 
December 31, 2017 extends to March 2020.

We could become materially exposed to credit risk with one 
or more of our counterparties if natural gas prices 
experience a significant increase. If a counterparty were to 
become insolvent or fail to perform on its obligations, we 
could suffer a material loss; however, we would expect such 
a loss to be eligible for regulatory deferral and rate recovery, 
subject to a prudence review. All of our existing 
counterparties currently have investment-grade credit 
ratings.

Fair Value
In accordance with fair value accounting, we include non-
performance risk in calculating fair value adjustments. This 
includes a credit risk adjustment based on the credit 
spreads of our counterparties when we are in an unrealized 
gain position, or on our own credit spread when we are in an 
unrealized loss position. The inputs in our valuation models 
include natural gas futures, volatility, credit default swap 
spreads, and interest rates. Additionally, our assessment of 
non-performance risk is generally derived from the credit 
default swap market and from bond market credit spreads. 
The impact of the credit risk adjustments for all outstanding 

derivatives was immaterial to the fair value calculation at 
December 31, 2017. As of December 31, 2017 and 2016, 
the net fair value was a liability of $20.3 million and an asset 
of $18.1 million, respectively, using significant other 
observable, or Level 2, inputs. No Level 3 inputs were used 
in our derivative valuations, and there were no transfers 
between Level 1 or Level 2 during the years ended 
December 31, 2017 and 2016. 

14. COMMITMENTS AND CONTINGENCIES

Leases
We lease land, buildings, and equipment under agreements 
that expire in various years, including a 99-year land lease 
that extends through 2108. Rental costs were $7.5 million, 
$6.2 million, and $5.5 million for the years ended December 
31, 2017, 2016, and 2015, respectively, a portion of which is 
capitalized. The following table reflects the future minimum 
lease payments due under non-cancelable leases at 
December 31, 2017. These commitments relate principally 
to the lease of our office headquarters, underground gas 
storage facilities, and computer equipment.

In thousands

Operating
leases

Capital
leases

$

5,378

$

3

$

5,379

6,945

7,482

7,629

169,411

—

—

—

—

—

Minimum
lease
payments

5,381

5,379

6,945

7,482

7,629

169,411

$

202,224

$

3

$

202,227

2018

2019

2020

2021

2022

Thereafter

   Total

In October 2017, we entered into a 20-year operating lease 
agreement for a new headquarters in Portland, Oregon in 
anticipation of the expiration of our current lease in 2020. 
Payments under the new lease are expected to commence 
in 2020. Total estimated base rent payments over the life of 
the lease are approximately $160 million and have been 
included in the table above. We have the option to extend 
the term of the lease for two additional seven-year periods.

Additionally, the lease was analyzed in consideration of  
build-to-suit lease accounting guidance, and we concluded 
that we are the accounting owner of the asset during 
construction. As a result, we recognized $0.5 million in 
Property, plant and equipment and an obligation in Other 
non-current liabilities for the same amount on our 
consolidated balance sheet at December 31, 2017.

Gas  Purchase  and  Pipeline  Capacity  Purchase  and 
Release Commitments
We have signed agreements providing for the reservation of 
firm pipeline capacity under which we are required to make 
fixed monthly payments for contracted capacity. The pricing 
component of the monthly payment is established, subject 
to change, by U.S. or Canadian regulatory bodies. In 
addition, we have entered into long-term sale agreements to 
release firm pipeline capacity. We also enter into short-term 
and long-term gas purchase agreements. 

85

  
 
 
remediation costs and record a reasonable potential 
remediation liability, or make an adjustment to our existing 
liability. From this study, the regulatory agency selects a 
remedy and issues a Record of Decision (ROD).

After a ROD is issued, we would seek to negotiate a 
consent decree or consent judgment for designing and 
implementing the remedy. We would have the ability to 
further refine estimates of remediation liabilities at that time. 

Remediation may include treatment of contaminated media 
such as sediment, soil and groundwater, removal and 
disposal of media, institutional controls such as legal 
restrictions on future property use, or natural recovery. 
Following construction of the remedy, the EPA and ODEQ 
also have requirements for ongoing maintenance, 
monitoring, and other post-remediation care that may 
continue for many years. Where appropriate and reasonably 
known, we will provide for these costs in our remediation 
liabilities described below.

Due to the numerous uncertainties surrounding the course 
of environmental remediation and the preliminary nature of 
several site investigations, in some cases, we may not be 
able to reasonably estimate the high end of the range of 
possible loss. In those cases, we have disclosed the nature 
of the possible loss and the fact that the high end of the 
range cannot be reasonably estimated where a range of 
potential loss is available. Unless there is an estimate within 
the range of possible losses that is more likely than other 
cost estimates within that range, we record the liability at the 
low end of this range. It is likely changes in these estimates 
and ranges will occur throughout the remediation process 
for each of these sites due to our continued evaluation and 
clarification concerning our responsibility, the complexity of 
environmental laws and regulations, and the determination 
by regulators of remediation alternatives. In addition to 
remediation costs, we could also be subject to Natural 
Resource Damages (NRD) claims from third-party tribal 
entities. We will assess the likelihood and probability of each 
claim and recognize a liability if deemed appropriate. Refer 
to "Other Portland Harbor" below.  

The aggregate amounts of these agreements were as 
follows at December 31, 2017:

In thousands

2018

2019

2020

2021

2022

Thereafter

   Total

Less: Amount
representing
interest

Total at present
value

Gas
Purchase
Agreements

Pipeline
Capacity
Purchase
Agreements

Pipeline
Capacity
Release
Agreements

$

63,944

$

79,891

$

3,581

2,729

2,729

2,273

—

—

71,675

82,129

77,028

65,630

60,050

601,844

966,572

—

—

—

—

—

3,581

601

174,542

24

$

71,074

$

792,030

$

3,557

Our total payments for fixed charges under capacity 
purchase agreements were $85.3 million for 2017, $85.0 
million for 2016, and $85.2 million for 2015. Included in the 
amounts were reductions for capacity release sales of $4.5 
million for 2017, $4.5 million for 2016, and $4.4 million for 
2015. In addition, per-unit charges are required to be paid 
based on the actual quantities shipped under the 
agreements. In certain take-or-pay purchase commitments, 
annual deficiencies may be offset by prepayments subject to 
recovery over a longer term if future purchases exceed the 
minimum annual requirements.

Environmental Matters
Refer to Note 15 for a discussion of environmental 
commitments and contingencies.

15. ENVIRONMENTAL MATTERS

We own, or previously owned, properties that may require 
environmental remediation or action. We estimate the range 
of loss for environmental liabilities based on current 
remediation technology, enacted laws and regulations, 
industry experience gained at similar sites, and an 
assessment of the probable level of involvement and 
financial condition of other potentially responsible parties 
(PRPs). When amounts are prudently expended related to 
site remediation of those sites described herein, we have a 
recovery mechanism in place to collect 96.68% of 
remediation costs from Oregon customers, and we are 
allowed to defer environmental remediation costs allocated 
to customers in Washington annually until they are reviewed 
for prudence at a subsequent proceeding. 

Our sites are subject to the remediation process prescribed 
by the Environmental Protection Agency (EPA) and the 
Oregon Department of Environmental Quality (ODEQ). The 
process begins with a remedial investigation (RI) to 
determine the nature and extent of contamination and then 
a risk assessment (RA) to establish whether the 
contamination at the site poses unacceptable risks to 
humans and the environment. Next, a feasibility study (FS) 
or an engineering evaluation/cost analysis (EE/CA) 
evaluates various remedial alternatives. It is at this point in 
the process when we are able to estimate a range of 

86

Environmental Sites
The following table summarizes information regarding liabilities related to environmental sites, which are recorded in other 
current liabilities and other noncurrent liabilities on the balance sheet at December 31: 

In thousands

Portland Harbor site:

Gasco/Siltronic Sediments

Other Portland Harbor

Gasco/Siltronic Upland site

Central Service Center site

Front Street site

Oregon Steel Mills

Total

PORTLAND HARBOR SITE. The Portland Harbor is an 
EPA listed Superfund site that is approximately 10 miles 
long on the Willamette River and is adjacent to NW 
Natural's Gasco uplands sites. We are one of over one 
hundred PRPs to the Superfund site. In January 2017, the 
EPA issued its Record of Decision, which selects the 
remedy fund for the clean-up of the Portland Harbor site 
(Portland Harbor ROD). The Portland Harbor ROD 
estimates the present value total cost at approximately 
$1.05 billion with an accuracy between -30% and +50% of 
actual costs. 

Our potential liability is a portion of the costs of the remedy 
for the entire Portland Harbor Superfund site. The cost of 
that remedy is expected to be allocated among more than 
100 PRPs. In addition, we are actively pursuing clarification 
and flexibility under the ROD in order to better understand 
our obligation under the clean-up. We are also participating 
in a non-binding allocation process with the other PRPs in 
an effort to resolve our potential liability. The Portland 
Harbor ROD does not provide any additional clarification 
around allocation of costs among PRPs and, as a result of 
issuance of the Portland Harbor ROD, we have not modified 
any of our recorded liabilities at this time. 

We manage our liability related to the Superfund site as two 
distinct remediation projects: the Gasco/Siltronic Sediments 
and Other Portland Harbor projects.

Gasco/Siltronic Sediments. In 2009, NW Natural and Siltronic 
Corporation entered into a separate Administrative Order on 
Consent with the EPA to evaluate and design specific 
remedies for sediments adjacent to the Gasco uplands and 
Siltronic uplands sites. We submitted a draft EE/CA to the 
EPA in May 2012 to provide the estimated cost of potential 
remedial alternatives for this site. At this time, the estimated 
costs for the various sediment remedy alternatives in the 
draft EE/CA, for the additional studies and design work 
needed before the cleanup can occur, and for regulatory 
oversight throughout the clean-up range from $48.0 million 
to $350 million. We have recorded a liability of $48.0 million 
for the sediment clean-up, which reflects the low end of the 
range. At this time, we believe sediments at this site 
represent the largest portion of our liability related to the 
Portland Harbor site discussed above. 

87

Current Liabilities

Non-Current Liabilities

2017

2016

2017

2016

$

2,683

$

869

$

45,346

$

43,972

1,949

13,422

25

1,009

—

1,970

10,657

73

906

—

4,163

47,835

—

10,757

179

4,148

49,183

—

7,786

179

$

19,088

$

14,475

$

108,280

$

105,268

Other Portland Harbor. While we still believe liabilities 
associated with the Gasco/Siltronic sediments site represent 
our largest exposure, we do have other potential exposures 
associated with the Portland Harbor ROD, including NRD 
costs and harborwide clean-up costs (including downstream 
petroleum contamination), for which allocations among the 
PRPs have not yet been determined. 

The Company and other parties have signed a cooperative 
agreement with the Portland Harbor Natural Resource 
Trustee council to participate in a phased NRD assessment 
to estimate liabilities to support an early restoration-based 
settlement of NRD claims. One member of this Trustee 
council, the Yakama Nation, withdrew from the council in 
2009, and in 2017, filed suit against the Company and 29 
other parties seeking remedial costs and NRD assessment 
costs associated with the Portland Harbor, set forth in the 
complaint. The complaint seeks recovery of alleged costs 
totaling $0.3 million in connection with the selection of a 
remedial action for the Portland Harbor as well as 
declaratory judgment for unspecified future remedial action 
costs and for costs to assess the injury, loss, or destruction 
of natural resources resulting from the release of hazardous 
substances at and from the Portland Harbor site. The 
Yakama Nation has filed two amended complaints 
addressing certain pleading defects and dismissing the 
State of Oregon. We have recorded a liability for NRD 
claims which is at the low end of the range of the potential 
liability; the high end of the range cannot be reasonably 
estimated at this time. The NRD liability is not included in 
the aforementioned range of costs provided in the Portland 
Harbor ROD.

GASCO UPLANDS SITE. A predecessor of NW Natural, 
Portland Gas and Coke Company, owned a former gas 
manufacturing plant that was closed in 1958 (Gasco site) 
and is adjacent to the Portland Harbor site described above. 
The Gasco site has been under investigation by us for 
environmental contamination under the ODEQ Voluntary 
Clean-Up Program (VCP). It is not included in the range of 
remedial costs for the Portland Harbor site noted above. We 
manage the Gasco site in two parts: the uplands portion and 
the groundwater source control action. 

We submitted a revised Remedial Investigation Report for 

the uplands to ODEQ in May 2007. In March 2015, ODEQ 
approved the RA, enabling us to begin work on the FS in 
2016. We have recognized a liability for the remediation of 
the uplands portion of the site which is at the low end of the 
range of potential liability; the high end of the range cannot 
be reasonably estimated at this time.

In October 2016, ODEQ and NW Natural agreed to amend 
their VCP agreement to incorporate a portion of the Siltronic 
property adjacent to the Gasco site formerly owned by 
Portland Gas & Coke between 1939 and 1960 into the 
Gasco RA and FS, excluding the uplands for Siltronic. 
Previously, we were conducting an investigation of 
manufactured gas plant constituents on the entire Siltronic 
uplands for ODEQ. Siltronic will be working with ODEQ 
directly on environmental impacts to the remainder of its 
property.

In September 2013, we completed construction of a 
groundwater source control system, including a water 
treatment station, at the Gasco site. We have estimated the 
cost associated with the ongoing operation of the system 
and have recognized a liability which is at the low end of the 
range of potential cost. We cannot estimate the high end of 
the range at this time due to the uncertainty associated with 
the duration of running the water treatment station, which is 
highly dependent on the remedy determined for both the 
upland portion as well as the final remedy for our Gasco 
sediment exposure.  

OTHER SITES. In addition to those sites above, we have 
environmental exposures at three other sites: Central 
Service Center, Front Street, and Oregon Steel Mills. We 
may have exposure at other sites that have not been 
identified at this time. Due to the uncertainty of the design of 
remediation, regulation, timing of the remediation, and in the 
case of the Oregon Steel Mills site, pending litigation, 
liabilities for each of these sites have been recognized at 
their respective low end of the range of potential liability; the 
high end of the range could not be reasonably estimated at 
this time. 

Central Service Center site. We are currently performing an 
environmental investigation of the property under ODEQ's 
Independent Cleanup Pathway. This site is on ODEQ's list 
of sites with confirmed releases of hazardous substances, 
and cleanup is necessary. 

Front Street site. The Front Street site was the former 
location of a gas manufacturing plant we operated (the 
former Portland Gas Manufacturing site, or PGM). At 
ODEQ’s request, we conducted a sediment and source 
control investigation and provided findings to ODEQ. In 
December 2015, we completed a FS on the former Portland 
Gas Manufacturing site. 

In July 2017, ODEQ issued the PGM ROD. The ROD 
specifies the selected remedy, which requires a combination 
of dredging, capping, treatment, and natural recovery. In 
addition, the selected remedy also requires institutional 
controls and long-term inspection and maintenance. We 
revised the liability in the second quarter of 2017 to 
incorporate the estimated undiscounted cost of 
approximately $10.5 million for the selected remedy. 

88

Further, we have recognized an additional liability of $1.3 
million for additional studies and design costs as well as 
regulatory oversight throughout the clean-up. We plan to 
complete the remedial design in 2018 and expect to 
construct the remedy details during 2019. 

Oregon Steel Mills site. Refer to the “Legal Proceedings,” 
below.

Site Remediation and Recovery Mechanism (SRRM)
We have an SRRM through which we track and have the 
ability to recover past deferred and future prudently incurred 
environmental remediation costs allocable to Oregon, 
subject to an earnings test, for those sites identified therein. 
In the February 2015 Order establishing the SRRM (2015 
Order), the OPUC addressed outstanding issues related to 
the SRRM, which required us to forego the collection of $15 
million out of approximately $95 million in total 
environmental remediation expenses and associated 
carrying costs. 

As a follow-up to the 2015 Order, the OPUC issued an 
additional Order in January 2016 (2016 Order) regarding the 
SRRM implementation in which the OPUC: (1) disallowed 
the recovery of $2.8 million of interest earned on the 
previously disallowed environmental expenditure amounts; 
(2) clarified the state allocation of 96.68% of environmental 
remediation costs for all environmental sites to Oregon; and 
(3) confirmed our treatment of $13.8 million of expenses put 
into the SRRM amortization account was correct and in 
compliance with prior OPUC orders. As a result of the 2016 
Order, we recognized a $3.3 million non-cash charge in the 
first quarter, of which $2.8 million is reflected in other 
income and expense, net and $0.5 million is included in 
operations and maintenance expense.

COLLECTIONS FROM OREGON CUSTOMERS. Under the 
SRRM collection process there are three types of deferred 
environmental remediation expense:
•  Pre-review - This class of costs represents remediation 
spend that has not yet been deemed prudent by the 
OPUC. Carrying costs on these remediation expenses are 
recorded at our authorized cost of capital. The Company 
anticipates the prudence review for annual costs and 
approval of the earnings test prescribed by the OPUC to 
occur by the third quarter of the following year. 

•  Post-review - This class of costs represents remediation 
spend that has been deemed prudent and allowed after 
applying the earnings test, but is not yet included in 
amortization. We earn a carrying cost on these amounts 
at a rate equal to the five-year treasury rate plus 100 
basis points. 

•  Amortization - This class of costs represents amounts 
included in current customer rates for collection and is 
generally calculated as one-fifth of the post-review 
deferred balance. We earn a carrying cost equal to the 
amortization rate determined annually by the OPUC, 
which approximates a short-term borrowing rate.

In addition to the collection amount noted above, the Order 
also provides for the annual collection of $5.0 million from 
Oregon customers through a tariff rider. As we collect 
amounts from customers, we recognize these collections as 
revenue and separately amortize an equal and offsetting 

 
 
 
the original Order, or earlier if we gain greater certainty 
about our future remediation costs, to consider whether 
adjustments to the mechanism may be appropriate.  

WASHINGTON DEFERRAL. In Washington, cost recovery 
and carrying charges on amounts deferred for costs 
associated with services provided to Washington customers 
will be determined in a future proceeding.

Legal Proceedings
NW Natural is subject to claims and litigation arising in the 
ordinary course of business. Although the final outcome of 
any of these legal proceedings cannot be predicted with 
certainty, including the matter described below, we do not 
expect that the ultimate disposition of any of these matters 
will have a material effect on our financial condition, results 
of operations, or cash flows.

OREGON STEEL MILLS SITE. In 2004, NW Natural was 
served with a third-party complaint by the Port of Portland 
(the Port) in a Multnomah County Circuit Court case, 
Oregon Steel Mills, Inc. v. The Port of Portland. The Port 
alleges that in the 1940s and 1950s petroleum wastes 
generated by our predecessor, Portland Gas & Coke 
Company, and 10 other third-party defendants, were 
disposed of in a waste oil disposal facility operated by the 
United States or Shaver Transportation Company on 
property then owned by the Port and now owned by Evraz 
Oregon Steel Mills. The complaint seeks contribution for 
unspecified past remedial action costs incurred by the Port 
regarding the former waste oil disposal facility as well as a 
declaratory judgment allocating liability for future remedial 
action costs. No date has been set for trial. In August 2017, 
the case was stayed pending outcome of the Portland 
Harbor allocation process or other remediation. Although the 
final outcome of this proceeding cannot be predicted with 
certainty, we do not expect the ultimate disposition of this 
matter will have a material effect on our financial condition, 
results of operations, or cash flows. 

For additional information regarding other commitments and 
contingencies, see Note 14.

amount of our deferred regulatory asset balance through the 
environmental remediation operating expense line shown 
separately in the operating expense section of the income 
statement. 

We received total environmental insurance proceeds of 
approximately $150.0 million as a result of settlements from 
our litigation that was dismissed in July 2014. Under the 
2015 OPUC Order, one-third of the Oregon allocated 
proceeds were applied to costs deferred through 2012 with 
the remaining two-thirds applied to costs at a rate of $5.0 
million per year plus interest over the following 20 years. We 
accrue interest on the insurance proceeds in the customer’s 
favor at a rate equal to the five-year treasury rate plus 100 
basis points. As of December 31, 2017, we have applied 
$68.2 million of insurance proceeds to prudently incurred 
remediation costs allocated to Oregon. 

The following table presents information regarding the total 
regulatory asset deferred as of December 31:

In thousands
Deferred costs and interest (1)
Accrued site liabilities (2)

2017

2016

$

45,546

$

53,039

126,950

119,443

Insurance proceeds and interest

(94,170)

(98,523)

Total regulatory asset deferral(1)

$

78,326

$

73,959

Current regulatory assets(3)
Long-term regulatory assets(3)

6,198

72,128

9,989

63,970

(1)  

Includes pre-review and post-review deferred costs, amounts 
currently in amortization, and interest, net of amounts collected 
from customers.

(2)  Excludes 3.32% of the Front Street site liability, or $0.4 million 
in 2017 and $0.3 million in 2016, as the OPUC only allows 
recovery of 96.68% of costs for those sites allocable to 
Oregon, including those that historically served only Oregon 
customers.

(3)  Environmental costs relate to specific sites approved for 

regulatory deferral by the OPUC and WUTC. In Oregon, we 
earn a carrying charge on cash amounts paid, whereas 
amounts accrued but not yet paid do not earn a carrying 
charge until expended. We also accrue a carrying charge on 
insurance proceeds for amounts owed to customers. In 
Washington, a carrying charge related to deferred amounts will 
be determined in a future proceeding. Current environmental 
costs represent remediation costs management expects to 
collect from customers in the next 12 months. Amounts 
included in this estimate are still subject to a prudence and 
earnings test review by the OPUC and do not include the $5 
million tariff rider. The amounts allocable to Oregon are 
recoverable through utility rates, subject to an earnings test.

ENVIRONMENTAL EARNINGS TEST. To the extent the 
utility earns at or below its authorized Return of Equity 
(ROE), remediation expenses and interest in excess of the 
$5.0 million tariff rider and $5.0 million insurance proceeds 
are recoverable through the SRRM. To the extent the utility 
earns more than its authorized ROE in a year, the utility is 
required to cover environmental expenses and interest on 
expenses greater than the $10.0 million with those earnings 
that exceed its authorized ROE. 

Under the 2015 Order, the OPUC will revisit the deferral and 
amortization of future remediation expenses, as well as the 
treatment of remaining insurance proceeds three years from

89

NORTHWEST NATURAL GAS COMPANY
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)

Quarter ended

In thousands, except per share data

March 31

June 30

September 30

December 31

2017

Operating revenues

Net income (loss)

Basic earnings (loss) per share(1)

Diluted earnings (loss) per share(1)

2016

Operating revenues

Net income (loss)

Basic earnings (loss) per share(1)

Diluted earnings (loss) per share(1)

$

297,323

$

136,238

$

88,190

$

240,422

40,310

1.41

1.40

2,729

0.10

0.10

(8,495)

(0.30)

(0.30)

$

255,529

$

99,183

$

87,727

$

36,641

1.33

1.33

2,019

0.07

0.07

(8,040)

(0.29)

(0.29)

(90,167)

(3.14)

(3.14)

233,528

28,275

1.01

1.00

(1)   Quarterly earnings (loss) per share are based upon the average number of common shares outstanding during each quarter. Variations in 

earnings between quarterly periods are due primarily to the seasonal nature of our business. 

NORTHWEST NATURAL GAS COMPANY
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES

COLUMN A

COLUMN B

COLUMN C

Additions

COLUMN D

COLUMN E

Deductions

In thousands (year ended December 31)

2017

Reserves deducted in balance sheet from
assets to which they apply:

Allowance for uncollectible accounts

2016

Reserves deducted in balance sheet from
assets to which they apply:

Allowance for uncollectible accounts

2015

Reserves deducted in balance sheet from
assets to which they apply:

Allowance for uncollectible accounts

$

$

$

Balance at
beginning of
period

Charged to
costs and
expenses

Charged to
other accounts

Net write-offs

Balance at end
of period

1,290

$

865

$

— $

1,199

$

956

870

$

1,246

$

— $

826

$

1,290

969

$

760

$

— $

859

$

870

90

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ITEM 9. CHANGES IN AND DISAGREEMENTS 
WITH ACCOUNTANTS ON ACCOUNTING AND 
FINANCIAL DISCLOSURE 

None.

ITEM 9A. CONTROLS AND PROCEDURES

(a) Evaluation of Disclosure Controls and Procedures

Our management, under the supervision and with the 
participation of our Chief Executive Officer and Chief 
Financial Officer, has completed an evaluation of the 
effectiveness of the design and operation of our disclosure 
controls and procedures (as defined in Rules 13a-15(e) and 
15d-15(e) of the Securities Exchange Act of 1934, as 
amended (the Exchange Act)). Based upon this evaluation, 
our Chief Executive Officer and Chief Financial Officer have 
concluded that, as of the end of the period covered by this 
report, our disclosure controls and procedures were 
effective to ensure that information required to be disclosed 
by us and included in our reports filed or submitted under 
the Exchange Act is recorded, processed, summarized, and 
reported within the time periods specified in the 

Securities and Exchange Commission (SEC) rules and
forms and that such information is accumulated and 
communicated to management, including the Chief
Executive Officer and Chief Financial Officer, as appropriate 
to allow timely decisions regarding required disclosure.

(b) Changes in Internal Control Over Financial Reporting 

Our management is responsible for establishing and 
maintaining adequate internal control over financial 
reporting, as such term is defined in the Exchange Act Rule 
13a-15(f). There have been no changes in our internal 
control over financial reporting that occurred during the 
quarter ended December 31, 2017 that have materially 
affected, or are reasonably likely to materially affect, our 
internal control over financial reporting. 

The statements contained in Exhibit 31.1 and Exhibit 31.2 
should be considered in light of, and read together with, the 
information set forth in this Item 9(a). 

ITEM 9B. OTHER INFORMATION

None.

91

 
ITEM 10. DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE
The "Information Concerning Nominees and Continuing Directors", "Corporate Governance", and "Section 16(a) Beneficial 
Ownership Reporting Compliance" contained in our definitive Proxy Statement for the May 24, 2018 Annual Meeting of 
Shareholders is hereby incorporated by reference.

PART III

Name

David H. Anderson

Age at 
Dec. 31, 2017
56

Frank H. Burkhartsmeyer(1)

53

Brody J. Wilson(1)

Lea Anne Doolittle

James R.Downing

Kimberly A. Heiting(2)(3)

MardiLyn Saathoff

Grant M. Yoshihara(3)

Shawn M. Filippi

Thomas J. Imeson

Justin Palfreyman

Lori Russell

David A. Weber

38

62

48

48

61

62

45

67

39

58

58

Positions held during last five years

Chief Executive Officer and President (2016-  ); Chief Operating Officer and
President (2015-2016); Executive Vice President and Chief Operating Officer
(2014-2015); Executive Vice President Operations and Regulation (2013-2014);
Senior Vice President and Chief Financial Officer (2004-2013).

Senior Vice President and Chief Financial Officer (2017-  ); President and Chief
Executive Officer of Renewables, Avangrid Renewables (2015-2017); Senior
Vice President of Finance, Iberdrola Renewables Holdings, Inc. (2012-2015);
Vice President, Strategy, Planning & Market Fundamentals, Iberdrola
Renewables Holdings, Inc. (2005- 2012).

Vice President, Chief Accounting Officer, Controller and Treasurer (2017- ); Chief
Financial Officer (Interim), Treasurer, Chief Accounting Officer and Controller
(2016-2017); Chief Accounting Officer, Controller and Assistant Treasurer
(2016); Controller (2013-2015); Acting Controller (2013); Accounting Director
(2012-2013); Senior Manager, PriceWaterhouseCoopers LLP (2009-2012);
Manager, PriceWaterhouseCoopers LLP (2007-2009).

Senior Vice President and Chief Administrative Officer (2013-  ); Senior Vice
President (2008-2013); Vice President, Human Resources (2000-2007).

Vice President and Chief Information Officer (2017-  ); Chief Information Officer,
WorleyParsons (America's Division) (2016-2017); Executive Service Delivery
Manager for SAP, British Petroleum (2011-2015).

Vice President, Communications and Chief Marketing Officer (2015-  ); Chief
Marketing & Communications Officer (2013-2014); Chief Corporate
Communications Officer (2011-2013); Communications Director (2005-2011).

Senior Vice President, Regulation and General Counsel (2016-  ); Senior Vice
President and General Counsel (2015-2016); Vice President, Legal, Risk and
Compliance (2013-2014); Deputy General Counsel (2010-2013); Chief
Governance Officer and Corporate Secretary (2008-2014).

Senior Vice President, Utility Operations (2016-  ); Vice President, Utility
Operations (2007-2016); Managing Director, Utility Services (2005-2006);
Director, Utility Services (2004-2005).

Vice President, Chief Compliance Officer and Corporate Secretary (2016-  );
Vice President and Corporate Secretary (2015-2016); Senior Legal Counsel
(2011-2014); Assistant Corporate Secretary (2010-2014); Associate Legal
Counsel (2005-2010).

Vice President of Public Affairs (2014-  ); Director of Public Affairs, Port of
Portland (2006-2014).

Vice President, Strategy and Business Development (2017-  );Vice President,
Business Development (2016-2017); Director, Power, Energy and Infrastructure
Group, Lazard, Freres & Co. (2009-2016).

Vice President, Utility Services (2016-  ); Utility Field Operations Director
(2013-2016); Serve Customer Process Director (2008-2013).

President and Chief Executive Officer, NW Natural Gas Storage, LLC and Gill
Ranch Storage, LLC (2012-  ); Interim President and Chief Executive Officer, NW
Natural Gas Storage, LLC and Gill Ranch Storage, LLC (2011-2012); Chief
Operating Officer, NW Natural Gas Storage, LLC and Gill Ranch Storage, LLC
(2010-2011); Managing Director of Information Services and Chief Information
Officer (2005-2011); Director of Information Services and Chief Information
Officer (2001-2005).

(1)  Frank H. Burkhartsmeyer was appointed Senior Vice President and Chief Financial Office effective May 17, 2017, replacing Brody J. Wilson, who had been serving 
as Chief Financial Office on an interim basis. Effective May 17, 2017, Mr. Wilson was appointed Vice President, Chief Accounting Officer, Controller, and Treasurer.

(2)  Kimberly A. Heiting was appointed Senior Vice President, Communications and Chief Marketing Officer effective January 1, 2018. 
(3)  Grant M. Yoshihara announced his intention to retire effective March 31, 2018. The Board of Directors appointed Kimberly A. Heiting as Senior Vice President, 

Operations and Chief Marketing Officer and Jon Huddleston Vice President, Engineering and Utility Operations, effective March 31, 2018.

Each executive officer serves successive annual terms; present terms end on May 24, 2018. There are no family relationships 
among our executive officers, directors or any person chosen to become one of our officers or directors. NW Natural has 
adopted a Code of Ethics (Code) applicable to all employees and officers that is available on our website at www.nwnatural.com. 
We intend to disclose on our website at www.nwnatural.com any amendments to the Code or waivers of the Code for executive 
officers and directors.

92

ITEM 11. EXECUTIVE COMPENSATION

The information concerning "Executive Compensation", 
"Report of the Organization and Executive Compensation 
Committee", and "Compensation Committee Interlocks and 

Insider Participation" contained in our definitive Proxy 
Statement for the May 24, 2018 Annual Meeting of 
Shareholders is hereby incorporated by reference. 
Information related to Executive Officers as of December 
31, 2017 is reflected in Part III, Item 10, above.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND 
RELATED STOCKHOLDER MATTERS

The following table sets forth information regarding compensation plans under which equity securities of NW Natural are 
authorized for issuance as of December 31, 2017 (see Note 6 to the Consolidated Financial Statements):

Plan Category

Equity compensation plans approved by security holders:

LTIP (1)(2)

Restated Stock Option Plan

Employee Stock Purchase Plan

Equity compensation plans not approved by security holders:

Executive Deferred Compensation Plan (EDCP)(3)
Directors Deferred Compensation Plan (DDCP)(3)
Deferred Compensation Plan for Directors and Executives (DCP)(4)

Total

(a)

(b)

(c)

Number of securities
to be issued upon
exercise of
outstanding options,
warrants and rights

Weighted-average
exercise price of
outstanding options,
warrants and rights

Number of securities
remaining available
for future issuance
under equity
compensation plans
(excluding securities
reflected in column
(a))

171,995

91,688

$

22,804

1,132

42,936

176,265

506,820

n/a

44.43

56.53

n/a

n/a

n/a

626,960

—

37,857

n/a

n/a

n/a

664,817

(1)  Awards may be granted under the LTIP as Performance Share Awards, Restricted Stock Units, or stock options. Shares issued pursuant to 
Performance Share Awards and Restricted Stock Units under the LTIP do not include an exercise price, but are payable when the award 
criteria are satisfied. The number of shares shown in column (a) include 84,522 Restricted Stock Units and 87,473 Performance Share 
Awards, reflecting the number of shares to be issued as targeted performance share awards under outstanding Performance Share Awards. 
If the maximum awards were paid pursuant to the Performance Share Awards outstanding at December 31, 2017, the number of shares 
shown in column (a) would increase by 87,473 shares, reflecting the maximum share award of 200% of target, and the number of shares 
shown in column (c) would decrease by the same amount of shares. No stock options or other types of award have been issued under the 
LTIP.
The number of shares shown in column (c) includes shares that are available for future issuance under the LTIP as Restricted Stock Units, 
Performance Share Awards, or stock options at December 31, 2017.

(2) 

(3)  Prior to January 1, 2005, deferred amounts were credited, at the participant’s election, to either a “cash account” or a “stock account.” If 
deferred amounts were credited to stock accounts, such accounts were credited with a number of shares of NW Natural common stock 
based on the purchase price of the common stock on the next purchase date under our Dividend Reinvestment and Direct Stock Purchase 
Plan, and such accounts were credited with additional shares based on the deemed reinvestment of dividends. Cash accounts are credited 
quarterly with interest at a rate equal to Moody’s Average Corporate Bond Yield plus two percentage points, subject to a 6% minimum rate. 
At the election of the participant, deferred balances in the stock accounts are payable after termination of Board service or employment in a 
lump sum, in installments over a period not to exceed 10 years in the case of the DDCP, or 15 years in the case of the EDCP, or in a 
combination of lump sum and installments. Amounts credited to stock accounts are payable solely in shares of common stock and cash for 
fractional shares, and amounts in the above table represent the aggregate number of shares credited to participants' stock accounts. We 
have contributed common stock to the trustee of the Umbrella Trusts such that the Umbrella Trusts hold approximately the number of 
shares of common stock equal to the number of shares credited to all participants’ stock accounts.

(4)  Effective January 1, 2005, the EDCP and DDCP were closed to new participants and replaced with the DCP. The DCP continues the basic 
provisions of the EDCP and DDCP under which deferred amounts are credited to either a “cash account” or a “stock account.” Stock 
accounts represent a right to receive shares of NW Natural common stock on a deferred basis, and such accounts are credited with 
additional shares based on the deemed reinvestment of dividends. Effective January 1, 2007, cash accounts are credited quarterly with 
interest at a rate equal to Moody’s Average Corporate Bond Yield. Our obligation to pay deferred compensation in accordance with the 
terms of the DCP will generally become due on retirement, death, or other termination of service, and will be paid in a lump sum or in 
installments of five, 10, or 15 years as elected by the participant in accordance with the terms of the DCP. Amounts credited to stock 
accounts are payable solely in shares of common stock and cash for fractional shares, and amounts in the above table represent the 
aggregate number of shares credited to participants' stock accounts. We have contributed common stock to the trustee of the Supplemental 
Trust such that this trust holds approximately the number of common shares equal to the number of shares credited to all participants' stock 
accounts. The right of each participant in the DCP is that of a general, unsecured creditor of the Company.

The information captioned “Beneficial Ownership of Common Stock by Directors and Executive Officers” and "Security 
Ownership of Common Stock of Certain Beneficial Owners" contained in our definitive Proxy Statement for the May 24, 2018 
Annual Meeting of Shareholders is incorporated herein by reference.

93

  
 
 
 
 
 
ITEM 13. CERTAIN RELATIONSHIPS AND 
RELATED TRANSACTIONS, AND DIRECTOR 
INDEPENDENCE

The information captioned "Transactions with Related 
Persons" and "Corporate Governance" in the Company’s 
definitive Proxy Statement for the May 24, 2018 Annual 
Meeting of Shareholders is hereby incorporated by 
reference.

ITEM 14. PRINCIPAL ACCOUNTANT FEES AND 
SERVICES

The information captioned "2017 and 2016 Audit Firm Fees" 
in the Company’s definitive Proxy Statement for the May 24, 
2018 Annual Meeting of Shareholders is hereby 
incorporated by reference.

PART IV

ITEM 15. EXHIBITS AND FINANCIAL STATEMENT 
SCHEDULES

(a)  The following documents are filed as part of this report:

1.  A list of all Financial Statements and Supplemental 

Schedules is incorporated by reference to Item 8.

2.  List of Exhibits filed:

Reference is made to the Exhibit Index 
commencing on page 95.

ITEM 16. FORM 10-K SUMMARY

None. 

94

  
 
NORTHWEST NATURAL GAS COMPANY
 Exhibit Index to Annual Report on Form 10-K
For the Fiscal Year Ended December 31, 2017 

Exhibit Number                                                        Document

*3a.

*3b.

*4a.

*4b.

*4c.

*4d.

*4e.

*4f.

*4g.

12

21

Restated Articles of Incorporation, as filed and effective May 31, 2006 and amended June 3, 2008 (incorporated
herein by reference to Exhibit 3.1 to Form 10-Q for the quarter ended June 30, 2008, File No. 1-15973).

Bylaws as amended December 21, 2017 (incorporated herein by reference to Exhibit 3.1 to Form 8-K dated
December 21, 2017, File No. 1-15973).

Copy of Mortgage and Deed of Trust, dated as of July 1, 1946, to Bankers Trust (to whom Deutsche Bank Trust
Company Americas is now successor), Trustee (incorporated herein by reference to Exhibit 7(j) in File No. 2-6494);
and copies of Supplemental Indentures Nos. 1 through 14 to the Mortgage and Deed of Trust, dated respectively, as
of June 1, 1949, March 1, 1954, April 1, 1956, February 1, 1959, July 1, 1961, January 1, 1964, March 1, 1966,
December 1, 1969, April 1, 1971, January 1, 1975, December 1, 1975, July 1, 1981, June 1, 1985 and November 1,
1985 (incorporated herein by reference to Exhibit 4(d) in File No. 33-1929); Supplemental Indenture No. 15 to the
Mortgage and Deed of Trust, dated as of July 1, 1986 (filed as Exhibit 4(c) in File No. 33-24168); Supplemental
Indentures Nos. 16, 17 and 18 to the Mortgage and Deed of Trust, dated, respectively, as of November 1, 1988,
October 1, 1989 and July 1, 1990 (incorporated herein by reference to Exhibit 4(c) in File No. 33-40482);
Supplemental Indenture No. 19 to the Mortgage and Deed of Trust, dated as of June 1, 1991 (incorporated herein by
reference to Exhibit 4(c) in File No. 33-64014); Supplemental Indenture No. 20 to the Mortgage and Deed of Trust,
dated as of June 1, 1993 (incorporated herein by reference to Exhibit 4(c) in File No. 33-53795); Supplemental
Indenture No. 21 to the Mortgage and Deed of Trust, dated as of October 15, 2012 (incorporated herein by reference
to Exhibit 4.1 to Form 8-K dated October 26, 2012, File No. 1-15973); and Supplemental Indenture No. 22 to the
Mortgage and Deed of Trust, dated as of November 1, 2016 (incorporated herein by reference to Exhibit 4.1 to Form
10-Q for the quarter ended September 30, 2016, File No. 1-15973).

Form of Secured Medium-Term Notes, Series B (incorporated herein by reference to Exhibit 4.1 to Form 8-K dated
October 4, 2004, File No. 1-15973).

Copy of Indenture, dated as of June 1, 1991, between the Company and Bankers Trust Company, Trustee, relating
to the Company’s Unsecured Medium-Term Notes (incorporated herein by reference to Exhibit 4(e) in File No.
33-64014).

Form of Credit Agreement among Northwest Natural Gas Company and the parties thereto, with JPMorgan
Chase Bank, N.A. as administrative agent and U.S. Bank, N.A. and Wells Fargo Bank, N.A. as co-syndication
agents, dated as of December 20, 2012 (incorporated herein by reference to Exhibit 4.1 to Form 8-K dated
December 21, 2012, File No.1-15973).

Form of Letter Agreement, between each of JPMorgan Chase Bank, N.A., Bank of America, N.A., Canadian
Imperial Bank of Commerce, Royal Bank of Canada, TD Bank, N.A., Union Bank, N.A., US Bank, N.A., and Wells
Fargo Bank, N.A., with JPMorgan Chase Bank, N.A. as Administrative Agent, extending the maturity date of the
Credit Agreement between Northwest Natural Gas Company and each financial institution, effective as of
December 20, 2013 (incorporated herein by reference to Exhibit 4k to Form 10-K for 2013, File No. 1-15973).

Form of Letter Agreement, between each of JPMorgan Chase Bank, N.A., Bank of America, N.A., Canadian
Imperial Bank of Commerce, Royal Bank of Canada, TD Bank, N.A., Union Bank, N.A., US Bank, N.A., and Wells
Fargo Bank, N.A., with JPMorgan Chase Bank, N.A. as Administrative Agent, extending the maturity date of the
Credit Agreement between Northwest Natural Gas Company and each financial institution, effective as of
December 20, 2014 (incorporated herein by reference to Exhibit 4m to Form 10-K for 2014, File No. 1-15973).

First Amendment to Credit Agreement, between the Company JPMorgan Chase Bank, N.A., Bank of America,
N.A., Canadian Imperial Bank of Commerce, Royal Bank of Canada, TD Bank, N.A., Union Bank, N.A., US Bank,
N.A., and Wells Fargo Bank, N.A., with JPMorgan Chase Bank, N.A. as Administrative Agent, dated as of
December 20, 2014 (incorporated herein by reference to Exhibit 4n to Form 10-K for 2014, File No. 1-15973).

Statement re computation of ratios of earnings to fixed charges.

Subsidiaries of Northwest Natural Gas Company.

95

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
23

Consent of PricewaterhouseCoopers LLP.

31.1

31.2

Certification of Principal Executive Officer Pursuant to Rule 13a-14(a)/15-d-14(a), Section 302 of the Sarbanes-
Oxley Act of 2002.

Certification of Principal Financial Officer Pursuant to Rule 13a-14(a)/15-d-14(a), Section 302 of the Sarbanes-
Oxley Act of 2002.

**32.1

Certification of Principal Executive Officer and Principal Financial Officer Pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002.

Executive Compensation Plans and Arrangements:

*10a.

*10b.

*10c.

*10d.

*10e.

*10f.

*10g.

*10h.

*10i.

*10j.

*10k.

*10l.

Executive Supplemental Retirement Income Plan 2010 Restatement (incorporated herein by reference to Exhibit
10b. to Form 10-K for 2009, File No. 1-15973).

Supplemental Executive Retirement Plan, 2011 Restatement (incorporated herein by reference to Exhibit 10.1 to
Form 10-Q for the quarter ended September 30, 2011, File No. 1-15973).

Northwest Natural Gas Company Supplemental Trust, effective January 1, 2005, restated as of December 15,
2005 (incorporated herein by reference to Exhibit 10.7 to Form 8-K dated December 16, 2005, File No. 1-15973).

Northwest Natural Gas Company Umbrella Trust for Directors, effective January 1, 1991, restated as of
December 15, 2005 (incorporated herein by reference to Exhibit 10.5 to Form 8-K dated December 16, 2005, File
No. 1-15973).

Northwest Natural Gas Company Umbrella Trust for Executives, effective January 1, 1988, restated as of
December 15, 2005 (incorporated herein by reference to Exhibit 10.6 to Form 8-K dated December 16, 2005, File
No. 1-15973).

Restated Stock Option Plan, as amended effective December 14, 2006 (incorporated herein by reference to
Exhibit 10c. to Form 10-K for 2006, File No. 1-15973).

Form of Restated Stock Option Plan Agreement (incorporated herein by reference to Exhibit 10h. to Form 10-K
for 2009, File No. 1-15973).

Executive Deferred Compensation Plan, effective as of January 1, 1987, restated as of February 26, 2009
(incorporated herein by reference to Exhibit 10e. to Form 10-K for 2008, File No. 1-15973).

Directors Deferred Compensation Plan, effective June 1, 1981, restated as of February 26, 2009 (incorporated
herein by reference to Exhibit 10f. to Form 10-K for 2008, File No. 1-15973).

Deferred Compensation Plan for Directors and Executives, effective January 1, 2005, restated as of July 28, 2016
(incorporated herein by reference to Exhibit 10.3 to Form 10-Q for the quarter ended June 30, 2016, File No.
1-15973).

Form of Indemnity Agreement as entered into between the Company and each director and certain executive
officers (incorporated herein by reference to Exhibit 10l. to Form 10-K for 2009, File No. 1-15973).

Form of Indemnity Agreement as entered into between the Company and certain executive officers (incorporated
herein by reference to Exhibit 10l.(1) to Form 10-K for 2009, File No. 1-15973).

*10m.

Non-Employee Directors Stock Compensation Plan, as amended effective December 15, 2005 (incorporated
herein by reference to Exhibit 10.2 to Form 8-K dated December 16, 2005, File No. 1-15973).

96

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*10n.

Executive Annual Incentive Plan, effective February 23, 2012, as amended effective January 1, 2016
(incorporated herein by reference to Exhibit 10p. to Form 10-K for 2015, File No. 1-15973).

10o.

Executive Annual Incentive Plan, effective January 1, 2017 (incorporated herein by reference to Exhibit 10o. to
Form 10-K for 2016, File No. 1-15973).

10p.

Executive Annual Incentive Plan, effective January 1, 2018.

*10q.

Form of Change in Control Severance Agreement between the Company and each executive officer (incorporated
herein by reference to Exhibit 10o. to Form 10-K for 2008, File No. 1-15973).

*10r.

Northwest Natural Gas Company Long Term Incentive Plan, as amended and restated effective May 24, 2012
(incorporated herein by reference to Exhibit 10r to Form 10-K for 2012, File No. 1-15973).

10s.

Northwest Natural Gas Company Long Term Incentive Plan, as amended and restated effective May 25, 2017.

*10t.

*10u.

*10v.

*10w.

Form of Long Term Incentive Award Agreement under the Long Term Incentive Plan (2015-2017) (incorporated by
reference to Exhibit 10w. to Form 10-K for 2014, File No. 1-15973).

Form of  Long Term Incentive Award Agreement under the Long Term Incentive Plan (2016-2018) (incorporated
herein by reference to Exhibit 10w. to Form 10-K for 2015, File No. 1-15973).

Form of Long Term Incentive Award Agreement under the Long Term Incentive Plan between the Company and
an Executive Officer (2016-2018) (incorporated herein by reference to Exhibit 10x. to Form 10-K for 2015, File
No. 1-15973).

Agreement to Amend the Long Term Incentive Award Agreement, under the Long Term Incentive Plan dated
February 25, 2016 by and between the Company and an executive officer (incorporated herein by reference to
Exhibit 10y. to Form 10-K for 2015, File No. 1-15973).

*10x.

Form of Long Term Incentive Award Agreement under Long Term Incentive Plan (2017-2019) (incorporated herein
by reference to Exhibit 10x. to Form 10-K for 2016, File No. 1-15973).

10y.

Form of Long Term Incentive Award Agreement under Long Term Incentive Plan (2018-2020).

*10z.

Form of Consent dated December 14, 2006 entered into by each executive officer with respect to amendments to
the Executive Supplemental Retirement Income Plan, the Supplemental Executive Retirement Plan and certain
change in control severance agreements (incorporated herein by reference to Exhibit 10.1 to Form 8-K dated
December 19, 2006, File No. 1-15973).

*10aa.

Consent to Amendment of Deferred Compensation Plan for Directors and Executives, dated February 28, 2008
entered into by each executive officer (incorporated herein by reference to Exhibit 10bb to Form 10-K for 2007,
File No. 1-15973).

10bb.

Form of Restricted Stock Unit Award Agreement under Long Term Incentive Plan (2018).

*10cc.

Corrected Form of Restricted Stock Unit Award Agreement under Long Term Incentive Plan (2017)(incorporated
herein by reference to Exhibit 10.1 to Form 10-Q for the quarter ended March 31, 2017, File No. 1-15973).

*10dd.

Form of Restricted Stock Unit Award Agreement under Long Term Incentive Plan (2016) (incorporated herein by
reference to Exhibit 10bb. to Form 10-K for 2015, File No. 1-15973).

97

 
 
 
 
 
 
 
 
 
 
 
 
 
*10ee.

Form of Amendment to Restricted Stock Unit Award Agreements (2013, 2014 and 2015) (incorporated herein by
reference to Exhibit 10cc to Form 10-K for 2016, File No. 1-15973).

*10ff.

Form of Restricted Stock Unit Award Agreement under the Long Term Incentive Plan (2013, 2014 and 2015)
(incorporated herein by reference to Exhibit 10aa. to Form 10-K for 2012, File No. 1-15973).

*10gg.

Form of Special Restricted Stock Unit Award Agreement under the Long Term Incentive Plan between the
Company and an executive officer (incorporated herein by reference to Exhibit 10a. to Form 10-Q for the quarter
ended March 31, 2014, File No. 1-15973).

*10hh.

Form of Director Restricted Stock Unit Award Agreement under the Long Term Incentive Plan (incorporated herein
by reference to Exhibit 10.1 to Form 10-Q for the quarter ended June 30, 2017, File No 1-15973).

*10ii.

*10jj.

*10kk.

*10ll.

Form of Director Restricted Stock Unit Award Agreement under Long Term Incentive Plan (incorporated herein by
reference to Exhibit 10a. to Form 10-Q for the quarter ended March 31, 2016, File No. 1-15973).

Severance Agreement between Northwest Natural Gas Company and an executive officer, dated August 1, 2016
(incorporated herein by reference to Exhibit 10.1 to Form 8-K dated July 29, 2016, File No. 1-15973).

Form of Restricted Stock Unit Award Agreement between the Company and an executive officer dated as of July
27, 2016 (incorporated herein by reference to Exhibit 10.1 to Form 10-Q for the quarter ended June 30, 2016, File
No. 1-15973).

Amended and Restated Cash Retention Agreement between the Company and an executive officer, dated as of
July 28, 2016 (incorporated herein by reference to Exhibit 10.2 to Form 10-Q for the quarter ended June 30,
2016, File No. 1-15973).

*10mm.

Form of Special Restricted Stock Unit Award Agreement under Long Term Incentive Plan between the Company
and an executive officer, dated as of September 30, 2016 (incorporated herein by reference to Exhibit 10.1 to
Form 10-Q for the quarter ended September 30, 2016, File No. 1-15973).

*10nn.

Form of Severance Agreement between the Company and an executive officer, dated May 17, 2017 (incorporated
herein by reference to Exhibit 10.1 to Form 8-K dated April 24, 2017, File No. 1-15973).

*10oo.

Form of Special Restricted Stock Unit Agreement between the Company and an executive officer, dated May 17,
2017 (incorporated herein by reference to Exhibit 10.2 to Form 8-K dated April 24, 2017, File No. 1-15973).

*10pp.

Form of Hire-On Bonus Agreement between the Company and an executive officer, dated May 17, 2017
(incorporated herein by reference to Exhibit 10.3 to Form 8-K dated April 24, 2017, File No. 1-15973).

10qq.

10rr.

10ss.

*10tt.

Form of Special Restricted Stock Unit Agreement between the Company and an executive officer, dated
September 30, 2016.

Form of Hire-On Bonus Agreement between the Company and an executive officer, date September 30, 2016.

Cash Retention Agreement between the Company and an executive officer, dated as of March 1, 2018.

Annual Incentive Plan for NW Natural Gas Storage, LLC, as amended effective January 1, 2017 (incorporated
herein by reference to Exhibit 10oo. to Form 10-K for 2016, File No. 1-15973).

*10uu.

Long Term Incentive Plan for NW Natural Gas Storage, LLC, as amended effective January 1, 2016 (incorporated
herein by reference to Exhibit 10pp. to Form 10-K for 2016, File No. 1-15973).

98

 
101.

The following materials from Northwest Natural Gas Company's Annual Report on Form 10-K for the fiscal year 
ended December 31, 2017, formatted in Extensible Business Reporting Language (XBRL):

(i) Consolidated Statements of Income;
(ii) Consolidated Balance Sheets;
(iii) Consolidated Statements of Cash Flows; and
(iv) Related notes.

*Incorporated herein by reference as indicated
**Pursuant to Item 601(b)(32)(ii) of Regulation S-K, this certificate is not being "filed" for purposes of Section 18 of the Securities 
Exchange Act of 1934, as amended.

99

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this 
report to be signed on its behalf by the undersigned, thereunto duly authorized.

NORTHWEST NATURAL GAS COMPANY

By: /s/ David H. Anderson
David H. Anderson
President and Chief Executive Officer
Date: February 23, 2018      

100

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons 
on behalf of the registrant and in the capacities and on the date indicated.

Signature

Title

Date

/s/ David H. Anderson

David H. Anderson
President and Chief Executive Officer

Principal Executive Officer and Director

February 23, 2018

/s/ Frank H. Burkhartsmeyer

Principal Financial Officer

February 23, 2018

Frank H. Burkhartsmeyer
Senior Vice President and Chief Financial Officer

/s/ Brody J. Wilson   

Principal Accounting Officer

February 23, 2018

Brody J. Wilson
Vice President, Treasurer, Chief Accounting Officer 
and Controller

)

)

)

)

)

)

)

)

)

)

)

February 23, 2018

)

)

)

)

)

)

)

)

)

)

)

)

)

)

/s/ Timothy P. Boyle 

Timothy P. Boyle 

/s/ Martha L. Byorum     

Martha L. Byorum

/s/ John D. Carter     

John D. Carter

/s/ Mark S. Dodson

Mark S. Dodson

/s/ C. Scott Gibson

C. Scott Gibson

/s/ Tod R. Hamachek

Tod R. Hamachek

/s/ Jane L. Peverett 

Jane L. Peverett 

/s/ Kenneth Thrasher  

Kenneth Thrasher

/s/ Malia H. Wasson

Malia H. Wasson

  Director

  Director

  Director

  Director

  Director

  Director

  Director

  Director

  Director

101

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
NORTHWEST NATURAL GAS COMPANY 
Ratios of Earnings to Fixed Charges 
(Unaudited)

EXHIBIT 12

In thousands, except share data

Fixed Charges, as defined:

Interest on Long-Term Debt
Other Interest
Amortization of Debt Discount and Expense
Capitalized Interest
Interest Portion of Rentals
Total Fixed Charges, as defined

Earnings, as defined:
Net Income (Loss)
Taxes on Income
Fixed Charges, as above
Total Earnings (Losses), as defined
Ratios of Earnings to Fixed Charges

Year Ended December 31,

2017

2016

2015

2014

2013

$

$

$

36,809
2,274
2,017
2,598
2,574
46,272

$

34,508
3,404
1,671
—
2,048
41,631

$

37,918
3,173
1,760
—
1,976
44,827

$

40,066
2,718
1,963
—
2,302
47,049

40,825
2,709
1,877
—
1,910
47,321

(55,623 )
58,895
(30,757 )
40,714
41,631
46,272
(40,108 ) $ 141,240
3.39

*

53,703
35,753
44,827
$ 134,283
3.00

58,692
41,643
47,049
$ 147,384
3.13

60,538
41,705
47,321
$ 149,564
3.16

* 

In 2017, earnings were insufficient to cover fixed charges by approximately $86.4 million primarily due to the impairment of long-
lived assets at the Gill Ranch Facility.

SUBSIDIARIES OF NORTHWEST NATURAL GAS COMPANY 
an Oregon Corporation

EXHIBIT 21

Name of Subsidiary

Gill Ranch Storage, LLC

NW Natural Energy, LLC

NW Natural Gas Storage, LLC

NNG Financial Corporation

Trail West Holdings, LLC

Trail West Pipeline, LLC

BL Credit Holdings, LLC

Northwest Biogas, LLC

KB Pipeline Company

Northwest Energy Corporation

Northwest Energy Sub Corporation

NWN Gas Reserves LLC

NW Natural Water Company, LLC

FWC Merger Sub, Inc.

Jurisdiction Organized

Oregon

Oregon

Oregon

Oregon

Delaware

Delaware

Delaware

Oregon

Oregon

Oregon

Oregon

Oregon

Oregon

Idaho

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

EXHIBIT 23

We hereby consent to the incorporation by reference in the Registration Statements on Form S 8 (Nos. 333-70218, 
333-100885, 333-120955, 333-134973, 333-139819, 333-180350, 333-187005, 333-214425, and 333-221347) and Form S-3 
(No. 333-214496) of Northwest Natural Gas Company of our report dated February 23, 2018 relating to the financial statements, 
financial statement schedule and the effectiveness of internal control over financial reporting, which appears in this Form 10 K. 

/s/ PricewaterhouseCoopers LLP

Portland, Oregon
February 23, 2018 

CERTIFICATION

I, David H. Anderson, certify that:

EXHIBIT 31.1

1.           I have reviewed this annual report on Form 10-K of Northwest Natural Gas Company;

2.           Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material 
fact necessary to make the statements made, in light of the circumstances under which such statements were made, not 
misleading with respect to the period covered by this report;

3.           Based on my knowledge, the financial statements, and other financial information included in this report, fairly present 
in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods 
presented in this report;

4.           The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and 
procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined 
in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under 
our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made 
known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed 
under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of 
financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our 
conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report 
based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the 
registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially 
affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5.           The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over 
financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons 
performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting 
which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial 
information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the 
registrant’s internal control over financial reporting.

Date:          February 23, 2018 

/s/ David H. Anderson                                                   
David H. Anderson
President and Chief Executive Officer

CERTIFICATION

I, Frank H. Burkhartsmeyer, certify that:

EXHIBIT 31.2

1.           I have reviewed this annual report on Form 10-K for Northwest Natural Gas Company;

2.           Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material 
fact necessary to make the statements made, in light of the circumstances under which such statements were made, not 
misleading with respect to the period covered by this report;

3.           Based on my knowledge, the financial statements, and other financial information included in this report, fairly present 
in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods 
presented in this report;

4.           The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and 
procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined 
in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under 
our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made 
known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed 
under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of 
financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our 
conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report 
based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the 
registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially 
affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5.           The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over 
financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons 
performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting 
which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial 
information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the 
registrant’s internal control over financial reporting.

Date: 

February 23, 2018 

/s/ Frank H. Burkhartsmeyer                                                                
Frank H. Burkhartsmeyer
Senior Vice President and Chief Financial Officer

NORTHWEST NATURAL GAS COMPANY
Certificate Pursuant to Section 906
of Sarbanes – Oxley Act of 2002

EXHIBIT 32.1

Each of the undersigned, DAVID H. ANDERSON, Chief Executive Officer, and FRANK H. BURKHARTSMEYER, Senior Vice 
President and Chief Financial Officer of NORTHWEST NATURAL GAS COMPANY (the Company), DOES HEREBY CERTIFY 
that:

1.           The Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (the Report) fully complies with 
the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2.           Information contained in the Report fairly presents, in all material respects, the financial condition and results of 
operations of the Company.

IN WITNESS WHEREOF, each of the undersigned has caused this instrument to be executed this 23th day of 

February 2018.

/s/ David H. Anderson                                                      
David H. Anderson
Chief Executive Officer

/s/ Frank H. Burkhartsmeyer                                                        
Frank H. Burkhartsmeyer
Senior Vice President and Chief Financial Officer

A signed original of this written statement required by Section 906 of the Sarbanes-Oxley Act of 2002 has been provided to 
Northwest Natural Gas Company and will be retained by Northwest Natural Gas Company and furnished to the Securities and 
Exchange Commission or its staff upon request.

 
 
 
COMMUNITY & SUSTAINABILITY REPORT 
Learn more about NW Natural’s community 
involvement and philanthropic contributions, 
environmental stewardship, employee safety
efforts and other company initiatives. 

View the Community & Sustainability
Annual Report at:
nwnatural.com/aboutnwnatural/community

LOW-INCOME PROGRAMS 
NW Natural helps low-income customers
manage their bills through a variety of
programs. Shareholders and customers
support the Gas Assistance Program, which 
supplements federal and state assistance
(cid:83)(cid:85)(cid:82)(cid:74)(cid:85)(cid:68)(cid:80)(cid:86)(cid:17)(cid:3)(cid:44)(cid:81)(cid:3)(cid:68)(cid:71)(cid:71)(cid:76)(cid:87)(cid:76)(cid:82)(cid:81)(cid:15)(cid:3)(cid:87)(cid:75)(cid:72)(cid:3)(cid:50)(cid:85)(cid:72)(cid:74)(cid:82)(cid:81)(cid:3)(cid:47)(cid:82)(cid:90)(cid:16)(cid:44)(cid:81)(cid:70)(cid:82)(cid:80)(cid:72)
Gas Assistance Program uses public purpose
fees to help low-income customers pay their
(cid:88)(cid:87)(cid:76)(cid:79)(cid:76)(cid:87)(cid:92)(cid:3)(cid:69)(cid:76)(cid:79)(cid:79)(cid:86)(cid:17)(cid:3)(cid:55)(cid:75)(cid:72)(cid:3)(cid:50)(cid:85)(cid:72)(cid:74)(cid:82)(cid:81)(cid:3)(cid:47)(cid:82)(cid:90)(cid:16)(cid:44)(cid:81)(cid:70)(cid:82)(cid:80)(cid:72)(cid:3)(cid:40)(cid:81)(cid:72)(cid:85)(cid:74)(cid:92)(cid:3)
(cid:40)(cid:73)(cid:403)(cid:70)(cid:76)(cid:72)(cid:81)(cid:70)(cid:92)(cid:3)(cid:51)(cid:85)(cid:82)(cid:74)(cid:85)(cid:68)(cid:80)(cid:15)(cid:3)(cid:68)(cid:79)(cid:86)(cid:82)(cid:3)(cid:83)(cid:68)(cid:76)(cid:71)(cid:3)(cid:73)(cid:82)(cid:85)(cid:3)(cid:69)(cid:92)(cid:3)(cid:83)(cid:88)(cid:69)(cid:79)(cid:76)(cid:70)(cid:3)
purpose charges, helps customers in need 
(cid:68)(cid:70)(cid:84)(cid:88)(cid:76)(cid:85)(cid:72)(cid:3)(cid:75)(cid:76)(cid:74)(cid:75)(cid:16)(cid:72)(cid:73)(cid:403)(cid:70)(cid:76)(cid:72)(cid:81)(cid:70)(cid:92)(cid:3)(cid:72)(cid:84)(cid:88)(cid:76)(cid:83)(cid:80)(cid:72)(cid:81)(cid:87)(cid:3)(cid:68)(cid:81)(cid:71)(cid:3)
weatherization upgrades.

(cid:57)(cid:76)(cid:72)(cid:90)(cid:3)(cid:87)(cid:75)(cid:72)(cid:3)(cid:47)(cid:82)(cid:90)(cid:16)(cid:44)(cid:81)(cid:70)(cid:82)(cid:80)(cid:72)(cid:3)(cid:51)(cid:85)(cid:82)(cid:74)(cid:85)(cid:68)(cid:80)(cid:86)(cid:3)(cid:68)(cid:87)(cid:29)
nwnatural.com/residential

ENERGY-EFFICIENCY PROGRAMS 
NW Natural partners with Energy Trust of 
Oregon to offer our Oregon and Washington
(cid:70)(cid:88)(cid:86)(cid:87)(cid:82)(cid:80)(cid:72)(cid:85)(cid:86)(cid:3)(cid:72)(cid:81)(cid:72)(cid:85)(cid:74)(cid:92)(cid:16)(cid:72)(cid:73)(cid:403)(cid:70)(cid:76)(cid:72)(cid:81)(cid:70)(cid:92)(cid:3)(cid:83)(cid:85)(cid:82)(cid:74)(cid:85)(cid:68)(cid:80)(cid:86)(cid:3)(cid:68)(cid:81)(cid:71)
services. Learn more about the results of these
(cid:83)(cid:85)(cid:82)(cid:74)(cid:85)(cid:68)(cid:80)(cid:86)(cid:3)(cid:68)(cid:81)(cid:71)(cid:3)(cid:87)(cid:75)(cid:72)(cid:3)(cid:69)(cid:72)(cid:81)(cid:72)(cid:403)(cid:87)(cid:86)(cid:3)(cid:87)(cid:82)(cid:3)(cid:82)(cid:88)(cid:85)(cid:3)(cid:70)(cid:88)(cid:86)(cid:87)(cid:82)(cid:80)(cid:72)(cid:85)(cid:86)(cid:17)

View the Energy Trust of Oregon 
Annual Report at:
nwnatural.com/residential

INVESTOR AND SHAREHOLDER    

    INFORMATION

STOCK TRANSFER AGENT 
AND REGISTRAR

For common stock:
American Stock Transfer
& Trust Company
6201 15th Avenue
Brooklyn, NY 11219
(888) 777-0321
web: astfinancial.com
email: info@(cid:68)(cid:86)(cid:87)(cid:403)(cid:81)(cid:68)(cid:81)(cid:70)(cid:76)(cid:68)(cid:79)(cid:17)(cid:70)(cid:82)(cid:80)

TRUSTEE AND
BOND PAYING AGENT 

For bond issues:
Deutsche Bank 
Trust Company Americas
60 Wall Street
New York, NY 10005
(800) 735-7777

NIKKI SPARLEY
(cid:39)(cid:76)(cid:85)(cid:72)(cid:70)(cid:87)(cid:82)(cid:85)(cid:15)(cid:3)(cid:44)(cid:81)(cid:89)(cid:72)(cid:86)(cid:87)(cid:82)(cid:85)(cid:3)(cid:53)(cid:72)(cid:79)(cid:68)(cid:87)(cid:76)(cid:82)(cid:81)(cid:86)
Toll free (800) 422-4012, Ext. 2530
Direct (503) 721-2530
nikki.sparley@nwnatural.com

CHU LEE
Manager, Shareholder Services
Toll free (800) 422-4012, Ext. 2402
Direct (503) 220-2402
chu.lee@nwnatural.com

220 NW SECOND AVENUE
PORTLAND, OREGON 97209
NWNATURAL.COM
NYSE: NWN