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Actions on the Pahsimeroi open up passage routes for returning salmon Print pdf version
| Historically, central Idaho’s Pahsimeroi River, a tributary of the Salmon, coiled through an abundant basin for spawning, migrating and rearing summer Chinook salmon, steelhead and westslope cutthroat. But for more than a century, parts of the Pahsimeroi and its tributaries have run dry in late summer and early fall because of water diversions for irrigated agriculture.
In 2008, BPA funded the Idaho Department of Water Resources to complete 20-year agreements that re-opened 10 miles of high-quality, spring-fed creek habitat previously impassable to fish. IDWR staff worked with the Idaho Department of Fish and Game and the Custer County Soil and Water Conservation District to remove the irrigation ditch and an associated cross ditch. These diversions had drained a creek with prime Chinook habitat and intercepted two springs that would otherwise feed cold water to the Pahsimeroi. One ditch also acted as an upstream fish migration barrier during low-water periods. Negotiated agreements allowed four landowners to change their point of diversion to the mainstem Pahsimeroi, where flow is not limited. As part of the project, the landowners also are switching from flood irrigation to more efficient sprinkler systems. The project restores nearly 30 cubic feet per second, or more than 13,000 gallons per minute, of clean, cold water. IDFG biologists report that adult salmon are already returning. 
Photo 3. Adult salmon responded by returning to the Pashsimeroi River and its tributaries where water was leased from farmers and ranchers in 2008.
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