Biological Assessment for Redlands Water and Power Company Fish Screen on the Gunnison River
Abstract
The Redlands Water and Power Company (RWPC) was established to supply irrigation water from the Gunnison River to the Redlands community near Grand Junction, Colorado. Gunnison River water is diverted at the Redlands Diversion Dam approximately 2.3 mile upstream of the Gunnison River’s confluence with the Colorado River (Figure 1). RWPC constructed the diversion dam in 1918 and has since modernized and updated the structure. The concrete dam is 8.5 feet high and consists of a 312-foot-long spillway with a 6-foot-wide crest and two 10-footwide by 6-foot-high sluice gates. A flow of 850 cubic feet per second (cfs) is diverted through four 14-foot-wide headgates on the west side into the Redlands Power Canal. The Redlands Power Canal is approximately 4 miles in length and terminates at Redland’s electric pumps and power plant. Pumped water is lifted to smaller distribution pipelines and canals to service the Redlands community. Water that passes through the power plant is discharged directly into the Colorado River. Figure 2 shows RWPC’s service area, which incorporates the Redlands Diversion Dam, Redlands Power Canal and delivery systems, and RWPC’s pumps and power plant. During the irrigation season (April-October), water is lifted 120 feet by electric pumps to supply water to RWPC shareholders or used for hydropower generation at the Redlands Power Plant. During the remaining portions of the year, water is diverted only to the Redlands Power Plant. In 1983, the Federal Energy Regulatory Commission (FERC) exempted RWPC from licensing under FERC regulations. This exemption required that fish passage be allowed around the dam. The Redlands Diversion Dam is a recognized barrier to upstream endangered fish movements; and the operation of the Diversion Dam, Redlands Power Canal, electric pumps and power plant can all result in the unauthorized incidental take of all life stages of the Colorado River endangered fishes. To assist in recovery efforts for the Colorado pikeminnow (Prychocheilus lucius) and razorback sucker (Xyrauchen texanus), RWPC has worked with the Upper Colorado River Endangered Fishes Recovery Program (Recovery Program) to minimize take. To mitigate for unavoidable incidental take of the Colorado pikeminnow and razorback sucker, Redlands has agreed to address potential impacts to Colorado pikeminnow and razorback sucker associated with RWPC operations. This biological assessment was prepared in consultation with the U.S. Fish and Wildlife Service (Service) and Recovery Program, and RWPC.