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<br />Final Report <br /> <br />3-53 <br /> <br />September 2000 <br /> <br />Restoration of floodplain habitats could be achieved through a combination of increased <br />peak flows, prolonged peak-flow duration, lower bank or levee heights, and constructed inlets. The <br />required flow level for inundation of floodplain habitat areas varies by reach, but the greatest <br />possibility for inundation occurs in Reach 2 within the Ouray portion of the river. Flows of 527 m3/s <br />are needed to begin inundation of floodplain habitats (514 ha flooded at this level); flows of 643 m3/s <br />result in 3,240 ha of inundated floodplain habitat. If existing levees were removed, lower flows <br />(between 368 and 453 m3/s) would produce flooding in Reach 2. Inundating floodplain habitat in the <br />lower portions of Reach 3 is problematic because of the vertical accretion (and natural levee <br />formation) that has occurred. Very high peak flows (greater than 1,104 m3/s) would be needed to <br />overtop the banks in this reach, and the degree of floodplain inundation would be relatively minor <br />even at higher flows. <br /> <br />The magnitude of peak flows in Reaches 2 and 3 can be maximized by linking the peak <br />release from Flaming Gorge Dam with spring peak and immediate post-peak flows of the Yampa <br />River. Because the drainage basins of the Yampa and upper Green Rivers have different <br />characteristics, the timings of peak runoff within the two basins do not always coincide, but the <br />resulting higher peaks would increase the effectiveness of the peak flow in restoring in-channel <br />processes and inundating floodplain habitats. <br /> <br />~ <br />