WSP01639 - Laserfiche WebLink

Home Browse Search

at this time were approximately between 5,700 and 7,600 cfs over the GVIC diversion dam, therefore it is suspected this fish passed around the structure via the bypass canal. This fish remained until late- September when it returned downstream and passed either over or around (via the OMID bypass canal or through the GVIC flood gates) the diversion dam. The same fish returned to the base of the GVIC Diversion in late-July 1987 and progressed upstream to the base of Price.Stubb Dam. It remained there until mid-September, when it again made its way downstream. passing the GVIC Diversion (Osmundson and Kaeding 1989). The purpose of this project is to provide upstream passage for endangered fishes. The structure is being designed to provide passage particularly during low flows because the structure is inundated at high flows (about 15,000 cfs) and fish can pass over the structure at these high flows. The passageway will be designed to provide passage during March through October with the most important biological period being May through mid.September (FLO Engineering, Inc. 1997). Unlike the fish passageway at Redlands Diversion Dam on the Gunnison River, the GVIC passage structure will not have a trapping facility to allow researchers to definitively determine the number and types of species using the passageway. The conceptual design phase of the project is underway and three alternatives have been proposed by FLO Engineering, Inc., to modify the GVIC diversion dam to allow for passage of Colorado River endangered fishes. The three alternatives are currently being evaluated by Bureau of Reclamation and Fish and Wildlife personnel. Selection of the final design is scheduled for spring of 1997 with intent of awarding a construction contract by August 1997. Plans are for the fish passageway to be operational April 1998. Although the final fish passage pattern and design has not been selected for GVIC, initial sentiment is that a drop structure consisting of series of approximately five pools and five riffles that creates a natural channel for passage would be the most preferred and appropriate for this site. Also. this type of structure would be more natural than the fish passageway constructed at Redlands Diversion Dam on the Gunnison River. Moreover. the passage option constructed at GVIC could be compared to that at Redlands to determine which type might be more effective in passing sub-adult and adult Colorado squawfish at other similar instream barriers in the Upper Colorado River Basin. ) GVIC 3