Scotts Flat Reservoir Spillway Restoration Project

The Scotts Flat Reservoir is a vital resource for the communities of western Nevada County. It provides treated and raw water for residential, agricultural, and commercial users; supports regional recreation; sustains local wildlife habitat; and contributes significantly to the area’s economy. As the primary mid‑elevation storage facility for Nevada County—and located near the communities of Nevada City and Grass Valley—the reservoir is essential to maintaining reliable water supply for both urban and disadvantaged populations.

In addition to its water‑supply importance, the Scotts Flat hydropower facility generates 875 kilowatts of clean, renewable electricity, contributing to regional environmental and sustainability goals.

The existing spillway, built in the 1950s, has experienced recurring structural issues over time, including significant spall damage, and was further stressed during the 2017 flood events. Following rigorous statewide assessments, both the California Division of Safety of Dams (DSOD) and the Federal Energy Regulatory Commission (FERC) determined that the spillway must be replaced. The facility is classified as High Hazard, underscoring the serious public‑safety implications should the structure fail. The spillway is essential to protecting the dam’s earthen rock‑fill infrastructure from severe erosion during high‑flow events.

NID needs your help. Please download our Letter of Support template and submit a filled out copy at the form below.