Work on Nelson Dam Project to Result in Temporary Lane Closure

Work continues on the Nelson Dam removal and replacement project, requiring a temporary single lane closure of South Naches Road at Powerhouse Road. This lane closure began Tuesday, September 6th, and continues through Friday, October 7th. It is in effect during scheduled project work hours of 6:00 am to 5:00 pm each day.

Flaggers and signs will be on site to assist drivers as traffic through the project area will be reduced to one lane during scheduled work hours.

Work scheduled over the next three weeks includes pouring concrete for a new fish screen structure and rip-rap installation.

As always, the schedule for this type of project is subject to change daily dependent on weather, equipment failure, and emergencies.

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 pour into the surrounding community during even minor flooding.

The Nelson Dam removal and replacement 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 City of Yakima and Yakima County have been collaborating on the design and implementation of the project for more than a decade. The dam removal and related work is one of several major public works projects initiated by the Yakima Basin Integrated Plan.

The City of Yakima plans to invest $10.8 million in the $26 million, multi-agency collaboration over the next four to five years.  To help pay for the project, the City of Yakima received $4.4 million from Washington State’s Floodplain by Design program, $4.134 million from Washington State’s Brian Abbott Fish Barrier Removal Board, and $1.298 million from the state’s Capital Budget and $500,000 from both the Resource Legacy Fund and the Bureau of Reclamation.

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