Anchorage sets Oct. 28 open house on Eklutna pumped storage options

Anchorage's contract for drinking water from Eklutna Lake now runs on a clock set by a decision on pumped storage hydropower, which stores energy by pumping water uphill for later release through turbines. Residents get their first formal look at the two dam options on Wednesday, Oct. 28, when the Municipality of Anchorage holds an open house on the Eklutna Pumped Storage Hydropower Study from 5:30 to 7:30 p.m. at Beach Lake Chalet, 17300 S Birchwood Loop Rd, in Chugiak. A virtual link will be posted before the meeting.

About 90 percent of Anchorage's public water comes from Eklutna Lake. The city pays the project owners about $1.2 million a year under a 1984 agreement. On May 12, the Anchorage Assembly extended that agreement only until the earliest of three dates: Oct. 1, 2027, 120 days after the Governor approves pumped storage, or 120 days after the owners decide not to pursue it.

Two alternatives remain. Alternative 3A is a West Hunter Creek project with a 300-foot dam and a diversion tunnel, while Alternative 3B uses a 170-foot dam, a diversion tunnel and a 12-foot raise in the lake's operating level. The study estimates the project would add 75,000 megawatt-hours of generation a year, with 55,000 from West Hunter and 20,000 from Eklutna.

A June 18 briefing to an Assembly committee listed fish passage, the transmission route, relocation of infrastructure, the cost estimate and the economic analysis as still in progress, with the cost estimate accurate only to within minus 30 and plus 50 percent. The records do not say how costs would split among the owners and water customers. The Municipality owns 53.33 percent of the project, with Chugach Electric Association and Matanuska Electric Association, but gave up its operating and voting rights in 2020, the governor's 2024 decision says.

Pumped storage entered the process through Gov. Mike Dunleavy's Oct. 2, 2024, decision. Dunleavy adopted the owners' fish and wildlife program and accepted a request from the Municipality and the Native Village of Eklutna to study pumped storage. A 2024 Assembly and Native Village of Eklutna joint resolution said the owners' program would cost at least $57 million and leave one mile of river dry below the dam. The Native Village of Eklutna calls for continuous flow across all 12 river miles and fish passage into and out of the lake, while co-owners Chugach Electric Association and Matanuska Electric Association have backed releasing water into the river and weighing fish passage later. "The Agreement does not provide any party the authority to unilaterally suspend or delay implementation of the Final Program," Dunleavy wrote.

The finished study goes next to the Monitoring and Adaptive Management Committee, made up of state and federal agency representatives, the Native Village of Eklutna and a governor's appointee, in early 2027. If the owners agree with the committee's analysis, they will recommend a path to the Governor, who issues the final order.