Changes to water control plan at Prado increases water supply in OC

A minor deviation to the Water Control Plan at Prado Dam is expected to increase water supply in Orange County.

A collaboration between the Orange County Water District and the U.S. Army Corps of Engineers, allows for higher water storage levels at Prado Dam, temporarily raising it to 508 feet above mean sea level, with potential future increases to 510 or 512 feet.

The District believes the adjustment will allow for the capture of an additional two billion gallons of stormwater, which is enough water to supply 48,000 people and save $6 million in imported water costs.

“This is a significant achievement in our longstanding efforts to enhance the Orange County Groundwater Basin,” said Denis Bilodeau, P.E., President of OCWD. “By raising the water storage levels at Prado Dam, we are capturing more Santa Ana River stormwater and enhancing our community’s drinking water reserves in a sustainable and efficient way.”

The approval of the deviation will be further enhanced by the complete implementation of Forecast Informed Reservoir Operations (FIRO) at Prado Dam, an initiative led by OCWD and the USACE, supported by the Center for Western Weather and Water Extremes (CW3E) at Scripps Institution of Oceanography.

FIRO has demonstrated enhanced capabilities for more accurately tracking atmospheric rivers, thereby improving the decision support process to maximize stormwater capture.

Over the next five years, the goal is to formally integrate FIRO into a decision-making process for water management, which will be documented in the water control manual, and to support achieving a higher permanent elevation for water storage. This project is poised to become the largest of its kind in Southern California and the second largest in the state.