Customers face double-digit rate increases under an Idaho Power Co. regulatory filing.

The proposed increase is 15.01% for irrigation customers under the annual power-cost adjustment the company filed with the Idaho Public Utilities Commission April 14.

Other proposed increases are 20.26% for large power users, 16.19% for large general service, 11.9% for residential and 9.7% for small general service.

Neither the company nor shareholders receive a financial return from the power-cost adjustment. It covers power costs incurred in the previous year and an estimate of the coming year’s energy costs.

“We understand times are tough for many, and we are sensitive to the impacts price increases have on our customers,” said Ryan Adelman, vice president of power supply. “Unfortunately, our power supply costs were higher in the past year because of continued drought conditions, high natural gas prices and fuel supply challenges, and we must recover those costs to maintain the reliable service our customers depend on.”

Despite the obstacles, the company is working hard to keep its prices 20-30% lower than the national average, he said.

The Boise-based company in mid-March filed its annual fixed-cost adjustment, which applies only to residential and small commercial customers. It is based on changes in usage per customer during the previous year.

The rate changes are scheduled to take effect June 1 if approved.