Rollins Reservoir Dam is part of the Nevada Irrigation District’s Yuba-Bear Hydroelectric Project. Since the construction of the dam in 1965, sediment accumulation—particularly in the Greenhorn Arm—has led to the loss of approximately 10,000 acre-feet (17%) of the reservoir’s original storage capacity. Sediment transport from Greenhorn Creek varies by water year type and flow conditions, contributing to rapid infill and encroachment from the Greenhorn Arm into the main reservoir.
JNA Consulting prepared an Environmental Impact Report in compliance with California Environmental Quality Act to support the implementation of a sediment removal and management project. The Environmental Impact Report addressed the removal and disposal of accumulated sediments to restore and maintain reservoir storage capacity, reduce the risk of further downstream sediment transport, and improve recreational access and use.