Navajo Reservoir on the San Juan River serves as a water storage, flood control and power generation project for the San Juan River Basin. Because of deep hypolimnetic release from the dam, water temperatures are cooler than natural pre-dam conditions. Post-dam release water temperatures during the summer months are 4-8 �C (39-46 �F) as compared to pre-dam temperatures of 20-25 �C (68-77 �F). Colder water temperatures from the dam to Shiprock (~80 mile; 129 km downstream of the dam) may negatively impact survival of native fish species living below the dam but benefit the tail-water trout fishery (Vanicek, 1967; Holden, 1973; USBR, 2003). Colorado pikeminnow and razorback sucker are endangered fish species native to the San Juan River. [...]
