Poley Allen Diversion

Modern irrigation key to restoring Tribal fishing rights

About the Project

The Lostine River flows from the Eagle Cap Wilderness Area in the Wallowa Mountains in northeastern Oregon as a designated Wild and Scenic River for 16 miles, then through agricultural lands for 14 miles before joining the Wallowa River, a tributary of the Grande Ronde River. The Lostine lies within the ancestral lands of the Nez Perce Tribe, providing sustenance and cultural significance to the Tribe. However, five irrigation diversions on the Wallowa River impede access to cold-water spawning grounds upstream for endangered salmonids and other fish species. The Nez Perce Tribe led removal of three of those diversions and has flow agreements to reduce the impact of another, but the Poley-Allen diversion continues to block fish passage during the low-flow months of summer.

The Lostine River provides an opportunity for the Nez Perce Tribe to restore a culturally important fishery. The Tribe conducted a series of studies to pinpoint conservation needs—key to bringing in new partners—and performed technical and construction work on diversion consolidation and removal. Restoration of the Lostine and its Chinook runs has also been a long-standing goal for federal agencies and the Oregon Department of Fish and Wildlife. The Bonneville Power Administration provides mitigation funding for the project.

The farmers who rely on water from the Westside-Poley Allen diversions are independent-minded operators of small family farms, mostly hay and alfalfa. With limited means, they were not able to support a diversion-replacement project until Freshwater Trust, in partnership with the Tribe, worked with farmers to find a design solution that meets the needs of farmers, fish, and the Tribe.

Owner: Poley Allen Ditch Companies
Size: 4 feet high, 45 feet wide
Project Cost: $300,000-400,000
ORF Investment: Engineering design
Miles Opened: 10 miles
Fish: ESA-listed salmonids (spring and summer Chinook, steelhead and bull trout), coho, lamprey, and trout
Status: Expected in 2023

  • Open 10 miles of spawning habitat, including portions of the Lostine River that are federally designated as Wild and Scenic and run through a national Wilderness area
  • Support restoration for listed spring and summer Chinnok, steelhead, bull trout as well as reintroduced coho, rainbow trout, and lamprey
  • Decrease farmers’ operation and maintenance costs
  • Restore traditional cultural practices and fisheries of the Nez Perce Tribe
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Project Partners

Nez Perce Tribe

The Freshwater Trust

Oregon Department of Fish and Wildlife

Oregon Water Resources Department

Oregon Watershed Enhancement Board

Washington State Department of Ecology

U.S. Bureau of Reclamation

U.S. Department of Agriculture, Natural Resources Conservation Service

National Fish and Wildlife Foundation, Columbia Basin Water Transactions Program

Farmers Conservation Alliance

Private Landowners