Warner Basin diversion dams

Opening fish passage to high elevation streams

About the Project

Warner Basin holds a series of shallow lakes and marshes in remote southeastern Oregon. Most of the streams in this arid region are diverted for agricultural use, typically with little or no provision for fish passage. The diversions affect the threatened Warner sucker and Warner Lakes redback trout, which spawn and rear in higher elevation streams, then forage as adults in the lakes.

The Western Native Trout Initiative, formed in 2006 as a collaborative of public and private entities working to conserve native trout across the West, and the Warner Basin Aquatic Habitat Partnership have identified 10 irrigation diversions in the Basin that impede fish migration from the Warner Lakes to the higher elevation habitat. Replacing these diversions with roughened channels or other fish-friendly infrastructure will open more than 34 stream miles and allow fish that rear in the Warner Lakes to access the prime spawning grounds in the upper basin on lands administered by the Bureau of Land Management and the Fremont National Forest.

After years of outreach and community engagement by the Lake County Umbrella Watershed Council and others, local landowners support changes to their diversions that will improve fish passage, increase water use efficiency, and reduce operations and maintenance costs.

Owner: Private and public landowners
Size: 10 small agricultural diversions
Project Cost: $10.2 million
ORF Investment: Design and construction
Miles Opened: 34 miles
Fish: Warner sucker (Oregon state and federally threatened), Warner Lakes redband trout (Oregon state sensitive and federal species of concern)
Status: Three dams removed, opening 35 river miles, with one dam removal expected per year through 2027

  • Open 35 stream miles of historic spawning and rearing habitat contributing to recovery of the federally listed Warner sucker
  • Upgrade irrigation systems to reduce maintenance costs and improve operational efficiency
  • Build community support for Basin restoration and infrastructure projects
  • Generate jobs in a remote rural area
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Project Partners

Western Native Trout Initiative

Oregon Watershed Enhancement Board

Lake County Umbrella Watershed Council

Lakeview Soil and Water Conservation District

Desert Fish Habitat Partnership

Oregon Department of Fish and Wildlife

U.S. Fish and Wildlife Service


U.S. Forest Service

Bureau of Land Management

Private landowners