Bonita is a census-designated place (CDP) in southern San Diego County, California, nestled between the cities of Chula Vista, National City, and San Diego. The population was 12,538 at the 2010 census.GeographyBonita is located at.According to the United States Census Bureau, Bonita has a total area of 5.1sqmi. 5.0sqmi of it is land and 0.1sqmi of it (2.71%) is water.While Bonita is politically designated as an unincorporated community, bounded by the incorporated cities of Chula Vista, San Diego and National City, it is closely associated with the geography of the Lower Sweetwater Valley. Thus considered, Bonita occupies about a five-mile (8 km) stretch of the Sweetwater River, its valley, and surrounding hills on either side, bounded upstream (east) by the Sweetwater Reservoir, and downstream (west) effectively by Interstate 805. The community crosses west of I-805—an area less than 160acre—reaching as far south and west as East H Street and Hilltop Drive. Its northern boundary is State Route 54 and its southern extent reaches approximately one mile (2 km) south of the river.