Orange County's (Calif.) Groundwater Authority Since 1933. The Orange County Water District (OCWD) manages the large groundwater basin underlying north and central Orange County that provides approximately 75 percent of the water for 2.5 million citizens. OCWD is committed to enhancing Orange County’s groundwater quality and reliability in an environmentally friendly manner. With more than 80 years of prudent planning and careful investment, OCWD has doubled the sustainable yield of the groundwater basin. OCWD is a special district established by the California State Legislature in 1933 and governed by a 10-member board of directors. Separate from the County of Orange, OCWD supplies water to residents in the cities of Anaheim, Buena Park, Costa Mesa, Cypress, Fountain Valley, Fullerton, Garden Grove, Huntington Beach, Irvine, La Palma, Los Alamitos, Newport Beach, Orange, Placentia, Santa Ana, Seal Beach, Stanton, Tustin, Villa Park, Westminster and Yorba Linda. Go to www.ocwd.com for more information.