About Orange County Water District:

Orange County Water District (OCWD) was formed in 1933 by a special act of the California State Legislature to protect Orange County’s rights to water in the Santa Ana River. OCWD’s primary responsibility is managing the vast groundwater basin under north and central Orange County that supplies water to more than 20 cities and water agencies, serving more than 2 million Orange County residents. Since 1933, OCWD has replenished and maintained the groundwater basin at safe levels while more than doubling the basin’s annual yield. This important source of water provides local groundwater producers with a reliable supply of high-quality water.

OCWD primarily recharges the basin with water from the Santa Ana River and to a lesser extent with imported water purchased from the Metropolitan Water District of Southern California. OCWD currently holds rights to all Santa Ana River flows reaching Prado Dam. Water enters the groundwater basin via settling or percolation ponds in the cities of Anaheim and Orange. Behind Prado Dam (constructed and owned by the U.S. Army Corps of Engineers for flood prevention), OCWD owns 2,400 acres in Riverside County, which OCWD uses for water conservation, water quality improvement and environmental enhancement.
 
OCWD monitors the groundwater taken out each year to ensure that the basin is not overdrawn; refills the basin; and carries out an assessment program to pay for operating expenses and the cost of imported replenishment water. The groundwater basin holds millions of acre-feet of water (an acre-foot satisfies the needs of two families for one year). The groundwater basin provides more than half of all water used within the District. Protection, safety and enhancement of groundwater are OCWD’s highest priorities. With one of the most sophisticated groundwater protection programs in the country, OCWD uses more than 700 wells providing more than 1,200 sampling points—from which OCWD takes more than 13,000 water samples and conducts more than 300,000 analyses every year. OCWD’s monitoring program looks for more than 300 constituents—which is more than the requirements of health agencies.
 
Water use efficiency is a major part of OCWD’s ongoing efforts to increase available local water supplies. Examples of water use efficiency include providing ultra low-flush toilets for free and organizing a hotel towel and sheet program.
 
OCWD is leading the way in purification of wastewater for reuse to provide a reliable, new, drought-proof source of water. The Groundwater Replenishment System, a joint project sponsored by OCWD and the Orange County Sanitation District, will produce enough near- distilled quality water for 144,000 families by 2007.
 
Additional efforts to increase local water supplies include expanding the capacity of the existing percolation facilities, treating poor quality water to make it useable, studying methods to extend the life of filtration membranes, improving advanced purification technologies, using bacteria to remove contaminants, and studying the quality of Santa Ana River water and other water-related issues. Other OCWD groundwater management and water quality activities focus on expanding the Prado wetlands, groundwater treatment at well heads, computer modeling of the groundwater basin and conservation of endangered or threatened species.
 
ABOUT GROUNDWATER:
It’s the high-quality water that makes up more than half of all water used in Orange County. The groundwater basin began forming millions of years ago as mountains eroded and ocean sediments filled a deep valley, trapping Santa Ana River water between the layers of accumulated sand and gravel. The deepest aquifers of the groundwater basin still contain pristine water that fell to the earth thousands of years ago. The water Orange County drinks today may have entered the basin one year, 100 years or 1,000 years ago, depending on the location and depth of the well. The groundwater basin holds between 10 million and 40 million acre-feet of water, of which 1.25 million to 1.5 million acre-feet is usable.
 
Groundwater has always been vital to the lives and livelihoods of Orange County residents. In the 1800s and early 1900s, Orange County’s growing agricultural industry thrived because of a reliable, easily obtainable supply of water—water pumped from the ground below. As farmers continued to pump groundwater and divert water from the Santa Ana River for irrigation, they noticed that groundwater levels were falling. Pumps had to be lowered deeper into the ground to pump out the same amount of water, requiring more energy. The question of seawater being drawn into the groundwater basin was of serious concern.
 
Orange County’s groundwater basin supplies about 60% of the water needs for residents and businesses in Anaheim, Buena Park, Costa Mesa, Cypress, Fountain Valley, Fullerton, Garden Grove, Huntington Beach, Newport Beach, Irvine, La Palma, Los Alamitos, Orange, Placentia, Santa Ana, Seal Beach, Stanton, Tustin, Villa Park, Westminster, and Yorba Linda.