ANNUAL INCENTIVE PLAN NW Natural Gas Storage LLC (company, or the company)

The purpose of the Annual Incentive Plan is to recognize and reward employees who have performed well and contributed to successful company performance as measured by key performance indicators.

This Plan is an annual incentive plan and each new calendar year commences a new Program Term. Each Program Term will begin on January 1 and conclude on December 31.

All regular employees of the company are eligible to participate in the Annual Incentive Plan. For all purposes of this AIP, a person who is an employee of Northwest Natural Gas Company (NW Natural) on full-time assignment to the company and designated by the Company Board of Directors (BOD) shall be considered to be a regular employee of the company during the period of that full-time assignment. In these situations, a designated participant in this AIP shall not be eligible for incentive compensation from NW Natural.

If the President of NWNGS is considered by NW Natural to be an executive officer of NW Natural for purposes of public disclosure, any decision of the BOD under this AIP that affects an award to the President shall be subject to and conditioned upon the approval of that decision by the Board of Directors of NW Natural or as delegated by the Board of Directors of NW Natural to the Organization and Executive Compensation Committee.

To be eligible for an award the Participant must have been employed by the company for at least one month during the Program Term. In addition, the Participant must be employed on the date of the plan payout to be

eligible for any award for the Program Term unless the Participants’ employment is terminated prior to the payout date of the Program Term due to one of the following: retirement(*), disability or death. Prorated awards will be determined by prorating the Participant’s final award by the number of days employed during the Program Term. Employees who transfer to or from employment or full-time assignment to Northwest Natural or another subsidiary will be eligible for a prorated award based upon the number of days they were eligible to participate in the EAIP.

(*) Retirement is defined as a minimum of 5 years of service (with the company or with an affiliate company) and age and service equals 70.

The formula for calculating the incentive award for the Program Term is as follows:

The company performance goals in the Plan are intended to align the interest of Participants with those of the company. The goals and the formula for determining the Company Performance Factor will be established by the NW Natural Gas Storage, LLC Board of Directors (the “Board of Directors”) at the start of each Program Term and set forth as Exhibit II. After the goals and formula are established for a Program Term, the Board of Directors retains discretion to modify the goals and formula, including adjusting the calculation of any financial or other goal to eliminate the effects of significant extraordinary, non-recurring or unplanned

items.

The IPF weight used in calculating the Individual Performance Factor will be established for each Participant by the President, subject to the approval of the Board of Directors at the beginning of the Program Term. Individual goals for each Participant will be established by the Participant’s leader (subject to the approval of the President, and for the President subject to the approval of the Board of Directors) at the beginning of each Program Term. Performance against these goals will be assessed by the Participant’s leader at the end of the Program Term (subject to the approval of the President, and for the President subject to the approval of the Board of Directors). This assessment will result in a rating on a scale of 0 to 1.5 (the “Individual Performance Factor”). The Participant will not receive an award if the Individual Performance Factor is less than 0.5.

Awards will be calculated and paid no later than March 15 following the end of the Program Term. Awards are subject to tax withholding unless the Participant made a prior election to defer the Award under the terms of the NW Natural Gas Company Deferred Compensation Plan for Directors and Executives if they are eligible for this plan. All awards shall be audited and approved by the Board of Directors prior to payment.

The Plan shall be administered by the Board of Directors. Except to the extent provided under “NW Natural Oversight” above. The Board of Directors shall have the exclusive authority and responsibility for all matters in connection with the operation and administration of the Plan. Except to the extent provided under “NW Natural Oversight: above. Decisions by the Board of Directors shall be final and binding upon all parties affected by the Plan, including the beneficiaries of Participants.