Restoring habitat for salmon is the aim of a newly-released proposal to send more water down the Eklutna River.
The owners of the Eklutna Hydroelectric Project, which pulls water from Eklutna Lake to produce power for Anchorage and the Mat-Su Borough, proposed a plan Oct. 27 to return water to much of the Eklutna River. The majority of that riverbed has been dry since the original hydro dam was built in 1929, and the owners expect this restoration could promote the return of four of the five species of salmon.
The proposal is the result of two years of studying measures to mitigate damages of the hydro project to fish and wildlife. The three owners of the project — Chugach Electric Association, Matanuska Electric Association and the Municipality of Anchorage — were required to study the project’s impact under the terms of a 1991 purchase agreement with the federal government.
Samantha Owen is a consultant with McMillen, an engineering company that led the study and analysis for the owners. She said the draft plan to return water to the river would use existing infrastructure from Anchorage’s water utility — Anchorage Water and Wastewater Utility, or AWWU — with minor modifications.
“Essentially, it’s utilizing the excess capacity in the AWWU tunnel to provide water,” Owen said. “And there would be modifications made in order to release water into the river, because currently there is no infrastructure that allows that.”
Eklutna Lake supplies the vast majority of the municipality’s water via a tunnel operated by the utility. The plan would divert about 10% of the water destined for the hydro power facility, and release it out of the water utility’s tunnel about one mile down the river. But that would mean the uppermost mile of the riverbed remains dry.
And some of the stakeholders prefer an alternative that would feed water back into the entire river, reconnecting it to — and allowing fish to pass through to — Eklutna Lake. The Native Village of Eklutna was not included in the terms of the 1991 agreement, but they have been consulted throughout the mitigation study process. Aaron Leggett, president of the village, said full river restoration could bring back all five species of wild salmon, including sockeye, which typically spawn in lakes, not rivers.
“This year, for example, there was no commercial fishing, sport fishing or subsistence for any of the wild caught fish in Upper Cook Inlet,” Leggett said. “So this is a unique opportunity to actually increase salmon habitat in an area that has been severely impacted, certainly in the last — in my lifetime.”
The hydro project owners studied an alternative that would allow their power production to continue and connect the river all the way to Eklutna Lake, but it would require removing the current dam, and building a new one. They estimated that would cost upwards of $300 million, compared to their preferred proposal that would cost about $57 million.
Costs would eventually be passed on to Anchorage and Mat-Su electric ratepayers and Anchorage property owners. Leggett said they believe the dam replacement would cost much less than the owners estimate, and that there are supplemental funding opportunities that the Native Village of Eklutna could secure.
The stakeholders will attempt to resolve their differences before holding public comment meetings in January. The final decision will come from the governor and is expected by October 2024.
Correction: An earlier version of this story misstated when the original hydro dam was built. It was built in 1929.