High Quality Content by WIKIPEDIA articles! The Sweetwater Dam is a dam across the Sweetwater River in San Diego County, California. As the crow flies, it sits about 12 miles (19 km) east of San Diego and 9 miles (14 km) northeast of Chula Vista; and just south of the city of La Presa. The 108-foot (33 m)-high masonry arch dam impounds 960-acre (390 ha) Sweetwater Reservoir.