Eyak Lake Weir: FAQs

By Amy Scudder

The Copper River Watershed Project continues to work with partners to replace the aging weir on Eyak Lake. Sockeye salmon spawn on the edge of Eyak Lake, and the lake serves as an emergency drinking water source for the Cordova community. 

After the U.S. Forest Service completed a survey of the current weir structure in 2020, partners agreed that preemptive efforts to upgrade the weir were a priority to avoid an unexpected weir failure. In 2021, we completed preliminary investigations, including the site survey, hydrological reports, geotechnical investigations, and concept designs. In 2022, we began data collection for discharge and velocity measurements at the project site. We also started the design process for a final design. Between 2023 and 2024, we completed the 20%, 35%, 65%, 95%, and 100% design and review processes with ample opportunity for community input. After nearly four years of work, we are incredibly excited to have 100% of the design documents finalized and are preparing to go out for bid, with construction occurring in 2025 and 2026. 

 

For complete project information, take a look at the project site and watch the short videos and presentations: 

https://copperriver.org/programs/fish-habitat-restoration/restoration/eyak-lake/eyak-lake-weir/ 

 

What is the Eyak Lake Weir?

In 1972, a sheet pile weir was installed at the outlet of Eyak Lake to re-establish the water surface to pre-earthquake (1964 Good Friday earthquake) levels and keep nearshore sockeye spawning beds submerged. During the Earthquake, the lake subsided, and many of the historic spawning beds were no longer covered in water. 

Why is the weir being replaced?

The current aging structure is failing, with leaks at the seams and a leaning bulge near the original boat passage slot, slowly lowering lake levels. The structure also acts as a dam at low water levels, making it difficult for fish to move between the lake and river. We will replace the old weir with an upgraded structure engineered to improve fish passage up and downstream of the weir, maintain current water levels….(then use rest of existing content, by Sockeye Salmon should both be capitalized). Replacing the old weir with an upgraded, engineered structure that takes all of these concerns into account will help to improve fish passage up and downstream of the weir significantly, maintain current water levels to protect important nearshore spawning sites for salmon, particularly Sockeye salmon, maintain current lakeshore property lines, maintain Eyak Lake as an emergency drinking water source, and improve safety around the structure. 

How will the construction process and weir replacement impact the use of Eyak Lake?

There are NO plans to change access to fishing in the areas around the weir. As with any construction project, temporary restrictions may allow crews to complete work, divert water, safely operate heavy equipment, and place large structures. The Copper River Watershed Project and our partners are committed to providing public notice and updating the community on the construction schedule. 

What is the current timeline?

December 2024: RFP issued, Pre-Bid Conference held

January 2025: Deadline for bidder questions, with responses to bidders and final bid deadline expected by the end of the month

February 2025: Award announcement and post-award orientation conference

March-August 2025: Construction schedules, materials stockpiling, materials testing, dewatering plan, stormwater pollution prevention plan and all pre-construction requirements completed

September 2025: Pre-construction submittal and final meetings between CRWP, partners, and awardee

Winter 2025/2026: Weir replacement construction and completion! 

The Exxon Valdez Oil Spill Trustee Council and Federal Highways are funding this project. Financial support from U.S. Fish & Wildlife Service (USFWS), U.S. Forest Service (USFS), and Alaska Department of Transportation & Public Facilities (ADOT&PF) covered initial planning work. Those contributions helped leverage a grant from the National Fish and Wildlife Foundation to complete the preliminary investigations back in 2021. The current project partners are a group of 13 organizations: Alaska Department of Fish and Game, Cordova Electric Cooperative, City of Cordova, Department of Natural Resources, ADOT&PF, DOWL, FEMA, NOAA, Native Village of Eyak, Prince William Sound Science Center, The Eyak Corporation, USFS, and USFWS.