After more than a decade of planning, Nelson Dam is being removed.

When complete, the project will replace Nelson Dam to improve fish passage and water supply reliability.

Nelson Dam, on the Naches tributary of the Yakima River, was built in the 1920s to divert irrigation water for Yakima and the Naches-Cowiche Irrigation Association. The original design did not allow any fish passage. The dam has held back tons of sediment and silt over the years, raising the river bed and causing the Naches River to overflow its banks and move into the surrounding community during even minor flooding.

The project will improve fish passage and sediment continuity to improve habitat, increase flow conveyance to decrease flooding risks for nearby landowners, and improve water supply reliability.

The Washington Dept. of Fish and Wildlife recently detailed how fish are being saved even as water levels are lowered to allow workers to carry out the project.

photo courtesy Yakima County

The City of Yakima and Yakima County have been collaborating on the design and implementation of this project. The dam removal and replacement is one of several major public works projects initiated by the Yakima Basin Integrated Plan.

The City of Yakima is investing $10.8 million in the $26 million multi-agency collaboration — part of the Yakima Basin Integrated Plan — over the next four to five years.

The City of Yakima received $4.4 million from the Washington State Floodplain by Design program, about $4.1 million from Brian Abbott Fish Barrier Removal Board, and just over $1.3 million from the state’s Capital Budget for the Nelson Dam project. The City continues to seek additional funding from state and federal sources to complete the project.

For more about the project, contact City of Yakima Assistant Public Works Director Dave Brown by phone at 509-575-6154 or by email at

More photos available at Nelson Dam Project Progress | Snapshots (