San Justo Dam is a dam and reservoir in San Benito County, California, about southwest of Hollister. The dam provides offstream water storage for the federal Central Valley Project via the Pacheco Conduit and Hollister Conduit fed by the San Luis Reservoir.
Completed in January 1986, the dam is an earthfill structure high. Along with a companion dike structure high, it forms a reservoir with a capacity of about .
San Justo Reservoir [CLOSED] was closed in 2008, following a Zebra Mussle infection and remains closed until further notice.