As a water wholesaler, the San Diego County Water Authoritys mission is to provide a safe and reliable supply of water to its 23 member agencies in the San Diego region. A member of the San Diego County Board of Supervisors serves as a representative to the Water Authority s board of directors. The Water Authority was formed in 1944 by the California state legislature, and operates under the County Water Authority Act, which can be found in the California State Water Code. The Water Authority is one member of the Metropolitan Water District of Southern California, and in its 60-year history the Water Authority has come to supply up to 90 percent of San Diego Countys water.