Patterson is a significant earth dam located in Alameda, California, with a primary purpose of water supply. Completed in 1962, this dam stands at a height of 100 feet and has a hydraulic height of 99.83 feet, providing a storage capacity of 46 acre-feet. The dam is regulated by the California Department of Water Resources (DWR) under the Safety of Dams program, with state jurisdiction and enforcement in place to ensure its safety and proper maintenance.

Despite its fair condition assessment as of September 2017, Patterson poses a significant hazard potential due to its location and structural specifics. The dam is subject to regular inspections with a frequency of once a year, with the most recent one conducted in February 2021. The dam's emergency action plan (EAP) status, risk assessment, and management measures are currently not available, indicating a potential area for improvement in terms of emergency preparedness and response.

Owned and operated by the local government, Patterson serves as a crucial water resource in the region, contributing to water supply needs in the area. With its strategic location and design, this dam plays a vital role in managing water resources and ensuring a reliable supply for the community. Continuous monitoring and adherence to safety regulations are essential to mitigate any potential risks associated with the dam and to maintain its functionality for the benefit of the local population.