Physical Sciences and Mathematics Commons^™

Waterfall Formation At A Desert River-Reservoir Delta Isolates Endangered Fishes, Charles N. Cathcart, Casey A. Pennock, Christopher A. Cheek, Mark C. Mckinstry, Peter D. Mackinnon, Mary M. Conner, Keith B. Gido

Wildland Resources Faculty Publications

Unforeseen interactions of dams and declining water availability have formed new obstacles to recovering endemic and endangered big-river fishes. During a recent trend of drying climate and declining reservoir water levels in the southwestern United States, a large waterfall has formed on two separate occasions (1989-1995 & 2001-present) in the transition zone between the San Juan River and Lake Powell reservoir because of deposited sediments. Because recovery plans for two large-bodied endangered fish species, razorback sucker (Xyrauchen texanus) and Colorado pikeminnow (Ptychocheilus lucius), include annual stockings in the San Juan River, this waterfall potentially blocks upstream …