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<br />._.~ .- <br />-~-.: <br /> <br />000351 <br /> <br />Gunnison River would be established and the work might be temporarily stopped if <br />turbidity readings exceed desired conditions. <br /> <br />Aspinall Operations <br /> <br />Releases from the Aspinall Unit and flows below the Gunnison Tunnel would be unaffected by <br />the project. Releases from Blue Mesa Dam during the draw down would be reduced to facilitate <br />the draw down and gradually increased during the refill. Blue Mesa and Morrow Point Dam <br />releases would be adjusted by Reclamation as needed to control Morrow Point Reservoir's <br />elevation at or near 7, 129 ft. and protect downstream water quality. During the draw down. Blue <br />Mesa releases could be made as peaking releases or uniform releases, The uniform releases <br />would reduce the potential for suspended sediment in the water. Reclamation proposes, to use <br />peak releases. witha commitment to change to uniform releases if turbidity increases <br />downstream, Gunnison Tunnel di versions will also not be affected, <br /> <br />Other Alternatives Eliminated for Detailed Analysis <br /> <br />Other alternatives considered but eliminated from detailed analysis included: <br /> <br />1. Usin!.! divers to clean the trash rack without a reservoir draw down. Th..' alternative was <br />,not considered feasible because of the reduced diver's bottom time (time actually <br />cleaning the trash racks). Under the proposed plan. divers would be working in 30 feet of <br />water. compared to 60 feet of water without the reservoir draw down, <br /> <br />2, Draw down of :'vlorrow Point Reservoir to elevation 7.100 ti, and using divers or crane to <br />clean the trash rack, This alternative was originally proposed but has been eliminated <br />because of landslide issues and the cost of monitoring landslide movement. Potential <br />impacts to downstream resources would also increase with additional exposed sediments as a <br />result of the additional reservoir draw down. <br /> <br />3. Timin!.! of Reservoir Draw Down, ,Alternate times of year for implementin!.! the trash rack <br />, . ~, <br />cleaning project were considered but found not feasibie, A reservoir drawn down in the <br />spring was considered not feasible because it could trigger landslide movements with <br />saturated soils, A winter reservoir draw down was also considered not feasible because of <br />potential trash rack icing problems and inclement weather. <br /> <br />7 <br />