1968 Opening day of fishing at San Vicente. San Vicente is a deep, steep-sided impounding reservoir on San Vicente Creek in the Cuyamaca Mountains. The dam was completed in 1943 and began receiving water from the First San Diego Aqueduct in 1947. The reservoir was closed to boating and fishing on Labor Day 2008 so that the San Diego County Water Authority could complete the largest dam raise in U.S. history, raising the dam by 117 feet and more than doubling the storage capacity to make San Vicente the largest dam in the county.