Briefing Paper to Accompany the Proposed Upper Colorado River and San Juan River Endangered Fish Recovery Act of 1997

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Capital construction projects funded and under construction since 1994 and to be funded by proposed legislation San Juan River Recovery Program Capital project requirements anticipated for the recovery of Colorado squawfish and razorback sucker in the San Juan River have been defined in three broad categories: fish passageways, propagation facilities and habitat modifications. While not all actions have been defined in these categories, preliminary research has defined generally what would be needed. Plans call for defining specific requirements in each category by the end of 1999. Fish passageways ($5 million) The Biology Committee has identified that expanding the range of the Colorado squawfish and razorback sucker to include all designated critical habitat within the San Juan River is important to recovering the fish. Such expansion would provide spawning locations higher in the system, where it is easier to maintain clean cobble, and would provide access to about 34 percent more backwater habitat. In a 40 -mile reach of river downstream from Farmington, five diversion dams block upstream migration, and could be resolved as described below: Cudei Diversion: This quarry rock diversion dam would be removed and replaced with a pipe siphon from the Hogback main canal. This would eliminate the barrier and would prevent larval fish from drifting out of the river and into diversion canals. Hogback Diversion: The Hogback Diversion currently is maintained by entering the river with a dragline and bulldozer each year -- sometimes several times during irrigation season -- and damming off the entire river to route water to the canal headworks and sluice gate. Excess water is returned to the river through the sluice gate. Providing passage at this diversion would involve constructing a new diversion dam of less than 6 feet high and incorporating fish passage into the design. Modification of the canal intake structure and some fish screening will be required to prevent from becoming trapped in the diversion canals. Four Corners Power Plant Diversion: This low concrete dam is a migration barrier at low flow conditions. Fish passage could be provided by constructing a long bypass channel around the dam. Proper timing of the pumping would help keep larval endangered fish out of the canals. San Juan Generating Station Diversion: This concrete dam blocks fish migration at nearly all flows. Fish passage could be provided by constructing a long bypass channel around the dam. Controlling the timing of pumping would prevent larval fish from becoming trapped in the canals.