Sweetwater Main, located in Chula Vista, California, is a gravity dam on the Sweetwater River with a height of 112 feet and a hydraulic height of 99 feet. Completed in 1888, this dam serves primarily for water supply purposes, with a storage capacity of 27,689 acre-feet and a surface area of 936 acres. The dam is regulated by the Department of Water Resources and is subject to regular inspections to ensure its structural integrity.

Despite being rated as having a high hazard potential, Sweetwater Main is currently assessed to be in fair condition as of September 2017. The dam has not undergone any modifications in recent years, and its emergency action plan was last revised in February 2021. The surrounding area is at risk of inundation in the event of a breach, but specific risk management measures and assessments are not detailed in the available data.

Water resource and climate enthusiasts interested in the historical significance and technical details of Sweetwater Main will find this structure to be a key component of water management in San Diego County. With its role in irrigation, tailings, and water supply, this dam stands as a testament to California's long-standing efforts to harness and protect its water resources.