President’s Message— Is the Drought Over?
The drought is not officially over. The State Water Resources Control Board (SWRCB) recently extended its existing water conservation regulations, which prohibit wasteful practices and set a conservation mandate for water suppliers without enough water reserves to withstand three more dry years. The SWRCB cited variable weather, significantly impacted groundwater basins, and areas, such as the Central Valley, which still depend on water tanks and bottled water. The SWRCB felt it more prudent to reevaluate the situation at the close of the rainy season.
It will take about 3.5 very wet years for the Orange County Groundwater Basin to refill, but we can still live comfortably, without pumping restrictions, in the meantime.
One reason is added stormwater capture. Except for required flood control releases, OCWD has been able to capture 100 percent of Prado Dam release flows since it began raining in November 2016 and has put the water back into the Orange County Groundwater Basin. This additional stormwater capture is due to temporary modifications in the operation of Prado Dam by the U.S. Army Corps of Engineers (Corps; UACE) to allow water conservation (formerly 498 feet) up to elevation 505 feet above mean sea level (amsl).
The temporary modifications to Prado Dam’s operations by the Corps, referred to as deviations, allowed capture of an additional 17,000 acre-feet of stormwater through January 27. That’s enough water for 136,000 people. Further rainfall events have allowed even greater amounts of stormwater capture.
The capture of stormwater and its recharge into the groundwater basin is the most economical way to replenish local water supplies and one of the most efficient. Maximizing the use of local water resources helps sustain future pumping from the basin.
The Orange County Water District appreciates our long and productive relationship with the USACE. This relationship has provided for notable successes in managing water resources in the Santa Ana River Watershed in Southern California.
The District and the Corps are currently working on a long-term plan called the Prado Feasibility Study that, if successful, could lead to permanently changing the Prado Water Control Manual to allow water conservation up to 505 feet amsl year-round.
We sincerely appreciate the leadership of the USACE and look forward to continued collaboration to refill the Orange County Groundwater Basin to bring it back to healthy pre-drought levels.
The basin is only about 25 percent full, but we are confident that with this new stormwater capture and natural recharge from recent rains, the 100 million gallons per day of Groundwater Replenishment System “new” water, and the availability of imported water, we will make significant progress in refilling the basin.
The above average rainfall has certainly improved our local water supply conditions, but groundwater levels are still below target elevations and we have to continue to be vigilant in managing the groundwater basin.
Photo: Chris Jones, U.S. Army Corps of Engineers provided this photo of Prado Dam looking over the reservoir at water surface elevation 503.49 feet.
 | Denis R. Bilodeau, P.E. |