The yakama nation will study, select, and design alternatives to improve fish passage and avoid entrainment at the prosser diversion on the lower yakima river of central washington state

The Bureau of Reclamation has awarded the Confederated Tribes and Bands of the Yakama Nation a $3,077,000 Cooperative Agreement under the Aquatic Ecosystem Restoration Program (CFDA 15.580). The project will study, select, and design alternatives to improve fish passage and avoid entrainment at the Prosser Diversion on the Lower Yakima River in Washington. The goals are to create safer passage conditions for anadromous species like steelhead, Chinook, coho, and sockeye salmon, as well as Pacific lamprey. This project is prioritized in the Yakima Basin Integrated Plan and supported by stakeholders including the Kennewick Irrigation District and Washington Department of Fish and Wildlife. The project performance period is from September 2024 to September 2027.

The prosser diversion supplies irrigation water through the chandler canal serving the kennewick division of reclamations yakima project. The DAM can divert more than 50% of yakima river flow at times, creating very dangerous fish passage conditions. A large proportion of the yakima basins smolts get entrained in the canal and suffer high mortality. Removal or modification of the DAM and headworks will create safer passage conditions for all anadromous species. These improvements will benefit all four populations comprising the yakima major population group of federally threatened middle columbia river (MCR) steelhead juveniles and adults juveniles and adults from the entire yakima populations of spring and summer run chinook, naturally spawning fall chinook, coho, and sockeye salmon and juvenile and adult pacific lamprey. The project is prioritized in the yakima basin integrated plan (ybip), a collaborative regional planning document supported by a wide diversity of stakeholders, and the project is supported by the kennewick irrigation district, washingtons department of fish and wildlife, and other members of the yakima integrated plan