Methow Valley Irrigation District East Diversion Renovation
Phase 2: Dam foundation removal (2008)
High flows during the spring 2008 runoff exposed the remaining dam foundation in some places and buried it further with sediment in others. By allowing the river time to expose areas of the dam that would still impact fish passage, MSRF minimized the impacts that would have occurred from excavation that would have been required in 2007 to remove the remaining structure. Based on guidance from our partners, Washington Fish and Wildlife and the Bureau of Reclamation, approximately two-thirds of the remaining dam foundation were removed in December of 2008. The effort required one long day of in-water work and resulted in re-creation of a more natural channel with complete fish passage, and with minimal cost and adverse affects to humans or the environment.
To further enhance fish habitat, a natural log barb was placed on the west side of the channel near the section of the dam foundation purposely left on the river bottom. Over time this area is expected to accumulate additional gravels and cobbles as bed load deposits bury the remainder of the structure. Besides providing for unimpeded passage, we expect this area will come to provide a variety of habitats for fish, including vital spawning gravels and hiding refuge.
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