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<br />The historical range of endangered fish species in the Colorado River has been fragmented by <br />construction of diversion dams that serve as barriers to fish movement. Under the No Action <br />alternative, this condition would continue on the river unless fish passageways were constructed <br />under different programs, Under No Action, a self-sustaining population of endangered fish <br />would be less likely to develop in the Colorado River upstream from Palisade, Even if the <br />endangered fish were stocked upstream, the larval fish could travel downstream over the dams <br />and not be able to return as adults. Other endangered species are not anticipated to be affected <br />under the No Action alternative. <br /> <br />Under the preferred alternative, the Colorado squawfish and razorback sucker would have access <br />to river reaches upstream of the GVIC Diversion Dam. Also this alternative would allow testing <br />of this more natural appearing fish passage as opposed to concrete-raceway type passages. The <br />proposal would improve the chances of restoring upstream populations and the chances of <br />ultimate recovery of the fish. If needed, fish screens would be added to prevent adult and sub- <br />adult fish from entering the GVIC Canal. <br /> <br />These fish screens would have an indirect benefit of preventing some nonnative fish from entering <br />the canal and eventually ending up in gravel pits and backwaters where they might expand their <br />populations and eventually re-enter the river as competitors with the endangered fish. It is <br />recognized that some larval endangered fish, if successful spawning occurs upstream, would be <br />lost in the canal; but it is predicted that the net effect would be beneficial. <br /> <br />The draft EA served as a Biological Assessment under the Endangered Species Act. The <br />proposed action would not affect threatened or endangered species with the exception of the <br />Colorado squawfish and the razorback sucker, These fish and their critical habitat may be <br />affected but in a beneficial manner. The biological opinion (D.S, Fish and Wildlife Service, 1997) <br />on the project supported this conclusion as well as conclusions that other endangered species <br />would not be affected. <br /> <br />Historic and Cultural Resources <br /> <br />The GVIC Diversion was constructed in the early 1880's but a flood destroyed the original <br />headgates in 1898 and were replaced in 1901 by the current structure (FLO Engineering, Inc, <br />1997). The original wooden headgate was replaced with a steel one in the winter of 1899-1900. <br />In the 1940's, a concrete cap was poured over the top of the original dam, and the original <br />wooden cribbing diversion dam was modified to add a concrete cutoffwall onthe upstream side <br />of the dam in about 1980. The GVIC canal system itself is considered eligible to the National <br />Register of Historic Places, primarily based on its importance in the settling of the Grand Valley. <br />An evaluation of the diversion dam itself is ongoing, Initial conclusions are that the diversion dam <br />(Cultural Resource site number 5 ME4665) is eligible to the National Register of Historic Places <br />under two criteria: its association with the Grand Valley Canal, the first Grand Valley area <br />irrigation project and as a resource that embod'fes the distinctive characteristics of a method of <br /> <br />18 <br />