State regulators order Avista to refund over-collected rates

LACEY, Wash. - On Dec. 19, 2025, the Washington Utilities and Transportation Commission rejected tariff sheets Avista filed in October 2024 and revised in December 2025. The commission previously allowed Avista's rate increase to recover costs related to the coal-fired Colstrip power plant, subject to refund. After considering the full record, the commission ordered Avista to file new tariff sheets that will result in a $5.86 million decrease in revenue. The decrease will be refunded to customers starting in January 2026 for rates Avista overcharged related to Colstrip.

Avista sought recovery for capital investments made in the coal plant in 2024 and 2025. The commission denied full recovery of the investments. Instead, they required Avista to prorate the amounts and not charge customers for any coal investments with an in-service date after Jan. 1, 2026, as they will no longer be necessary or useful to Washington customers. The commission allowed full recovery of investments made to protect health and safety at the plant.

Washington's Clean Energy Transformation Act (CETA) requires all electric utilities serving Washington to remove coal-fired electricity from rates by Dec. 31, 2025. To comply with CETA, Avista is transferring its 15 percent ownership share of Colstrip to NorthWestern Energy Corporation on Jan. 1, 2026. As part of the order, the commission required Avista to submit any future property transfers made to comply with CETA to the commission for review.

On Sept. 24, 2025, the commission held a public comment hearing where customers shared concerns over additional rate increases, subsidizing coal electricity for use by other states, and CETA compliance. The commission made their decision with these comments in mind. The order honors CETA and the public interest by supporting the transition to a clean energy economy, reducing burdens to vulnerable populations and highly impacted communities, and ensures fairness for customers.

About the UTC

The UTC regulates investor-owned electric and natural gas utilities in Washington. The commission ensures regulated companies provide safe, equitable, and reliable service to customers at reasonable rates, while earning a fair profit.

About Avista

Spokane-based Avista Utilities provides electricity to around 403,000 customers and natural gas to about 369,000 customers across 30,000 square miles in Washington, Idaho, Oregon, and Montana.