Spring Valley is a census-designated place in the East County region of San Diego County, California. The population was 28,205 at the time of the 2010 census. From 1970 through 1990, Spring Valley included what is now the La Presa CDP to the south; La Presa is still popularly considered to be a part of Spring Valley. Extended definitions of Spring Valley may also include the Casa de Oro neighborhood to the north, which belongs to the Casa de Oro-Mount Helix CDP. Locations in both La Presa and Casa de Oro use Spring Valley addresses.