Patterson, also known as Patterson Reservoir, is a state-owned water supply reservoir located in Livermore, California. Completed in 1962, this offstream earth dam stands at a height of 39 feet and has a storage capacity of 104 acre-feet. The primary purpose of the dam is to provide water supply for the surrounding area, highlighting its importance in managing water resources in the region.

Managed by the California Department of Water Resources (DWR) under the Safety of Dams program, Patterson is subject to regular state inspection, permitting, and enforcement to ensure its safety and functionality. The dam has been assessed to have a fair condition, with a high hazard potential. Despite its relatively small size with a surface area of 4 acres and a drainage area of 0, Patterson plays a crucial role in the local water infrastructure.

With a spillway width and other structural details not specified in the data, Patterson remains an essential component of the water management system in Alameda County and serves as a valuable resource for water supply in the region. As climate change continues to impact water resources, the monitoring and maintenance of dams like Patterson become increasingly vital in ensuring water security for communities in California.