What we do

As a public agency, OCWD takes on the water challenges of today and prepares to meet the region's water demands for generations to come.

OCWD manages three of Southern California’s greatest water supplies: the Santa Ana River, the Orange County Groundwater Basin and the Groundwater Replenishment System (GWRS). It ensures a reliable supply of high-quality water for more than 2.5 million residents in north and central Orange County, while protecting environmental habitats and natural resources.

The largest river in Southern California, the Santa Ana River begins in the San Bernardino Mountains and flows downstream to Prado Dam and on to the Pacific Ocean. OCWD owns and manages a 6-mile (9.7 kilometers) stretch of the river. River flows are affected by water use upstream and weather fluctuation, making them less reliable than other water supplies.

One of the largest of several coastal basins in Southern California, the Orange County Groundwater Basin contains approximately 500,000 acre-feet (162.9 billion U.S. gallons; 616.7 million cubic meters) of usable storage water and covers 270 square miles (69,930 hectares; 699.3 square kilometers). The underground basin is millions of years old and is 4,000 feet (1.2 kilometers) at its deepest point. Managed properly, the basin is a reliable source of water.

The GWRS is the world’s largest advanced water purification system for potable reuse. A joint project between OCWD and the Orange County Sanitation District, it provides water supplies that are added to the Orange County Groundwater Basin. GWRS water is also injected into coastal barrier wells to keep seawater out of the basin. GWRS water is highly reliable, even during times of drought.


Recharge basins

OCWD is responsible for managing the vast groundwater basin that provides most of northern and central Orange County’s drinking water. 

Groundwater management

Fountain Valley Water Quality Report

OCWD’s commitment to exceptional water quality requires comprehensive knowledge of groundwater quality and a thorough understanding of the quality of water produced by the Groundwater Replenishment System.

Water quality

Microfiltration building basement

OCWD's mission of providing a reliable water supply in a cost-effective manner is brought to life through its water reuse projects. 

Water reuse

Staff at RO vessels

Ensuring that Orange County businesses and residents continue to receive the water they need, when they need it, requires planning and investment. 

Sound planning

Prado Wetlands

The Orange County Water District’s award-winning environmental programs benefit both nature and water supplies.

Environmental stewardship

Link to Research and Development

OCWD's R&D department coordinates and conducts applied physical, chemical and biological research that supports and enhances the District’s core operational needs.

Research & development

Financial reporting award

Meeting Orange County's water needs requires an organization that is financially stable with the assets to withstand environmental and operational challenges.

Sound financial management

Legislative & community engagement

OCWD is dedicated to proactive public outreach, engagement and education.

Legislative & community engagement