As previously disclosed, on August 29, 2025, NW Natural filed a request for a general rate case (Rate Case) with the Washington Utilities and Transportation Commission (WUTC) under Washington's multi-year rate plan statute.

On March 23, 2026, NW Natural filed a settlement with the WUTC that addressed all issues but one in the Rate Case (Stipulation). The WUTC issued a final order in the Rate Case on July 29, 2026, which approved the Stipulation, subject to certain adjustments and conditions, and resolved the remaining litigated issue by preserving NW Natural's line extension allowance in Washington.

The incremental revenue requirement for each year is based off of the following assumptions:

Year 1

Year 2

Year 3

Revenue Requirement Increase

$20.1 million

$7.5 million

$7.4 million(2)

Capital Structure

•50.0% long-term debt

•50.0% common equity

•50.0% long-term debt

•50.0% common equity

•50.0% long-term debt

•50.0% common equity

Return on Equity

9.5%

Cost of Long-Term Debt

4.806%

4.863%

4.936%

Overall Rate of Return

7.15%

7.18%

7.22%

Average Rate Base

$328.0 million(1)

$368.2 million

$397.8 million