Grass Valley, also known as Grass Valley Lake, is a private water resource located in Blue Jay, California. Built in 1964 for flood risk reduction, this earth dam stands at a height of 35 feet and has a storage capacity of 243 acre-feet. The dam is situated on the Grass Valley Creek in San Bernardino County, and its primary purpose includes flood risk reduction, irrigation, recreation, and water supply.

Despite its satisfactory condition assessment, Grass Valley poses a high hazard potential, emphasizing the importance of regular inspections and maintenance. The dam has state jurisdiction, with permitting, inspection, and enforcement conducted by the California Department of Water Resources (DWR) under the Safety of Dams program. With a drainage area of 2.6 square miles and a surface area of 20 acres, Grass Valley plays a crucial role in managing water resources and mitigating flood risks in the region.

As an integral part of the water infrastructure in the area, Grass Valley serves as a vital resource for the surrounding community and contributes to the overall water management efforts in California. With its strategic location and multiple purposes, including flood risk reduction and water supply, Grass Valley highlights the importance of sustainable water resource management in the face of changing climate patterns and increasing water demands.