In 1977, as a result of a public initiative, South Bay Irrigation District and National City formed a joint powers public water agency, named Sweetwater Authority. Sweetwater Authority manages and operates the water system, providing water to National City, western portions of Chula Vista and Bonita, California.
Sweetwater Authority's governing board, or board of directors, is composed of seven members. Five directors are elected by division by the citizens of the South Bay Irrigation District. Two directors are appointed by the Mayor of National City, subject to City Council confirmation.