The Sites Project Authority announced findings from a new analysis, which projected that Sites Reservoir could have diverted and captured 120,000 acre-feet of water in just two weeks if the reservoir had been operational from Jan. 3 through Jan. 15.
Based on forecasted flows, the analysis shows that the reservoir would continue to capture water over the next few weeks as flows continue to run high.
“This is exactly the type of scenario that Sites is being built for—short windows of extremely high flows,” says Jerry Brown, executive director of the Sites Project Authority. “There is an untapped opportunity to capture and store a portion of the significant amount of flow from the Sacramento River that occurs during these rare but major storms without impacting the value of these high flows for our environment.”
Sites Reservoir is specifically designed to divert and store water generated by storm events, like the atmospheric rivers that drenched the state in recent weeks, to increase water flexibility, reliability, and resiliency in drier years.
The analysis found Sites Reservoir could have diverted 120,000 acre-feet of water—less than 4 percent of Delta outflow—from Jan. 3 to Jan. 15. Long-range forecasts estimated that Sites Reservoir would continue to divert stormwater through at least Feb. 15, for a total 382,000 acre-feet of water. A single acre-foot of water is enough to exceed the average annual indoor and outdoor water use of one to two California households, according to the Water Education Foundation.
“The rainstorms that pummeled Northern California would have been Sites’ time to shine,” says Alicia Forsythe, environmental planning and permitting manager of the Sites Project Authority. “It would have captured a portion of the flood waters for use in future dry times by farms, families, and ecosystems, while leaving lots of water in the Sacramento River and Delta for our environment and fisheries.”
While Sacramento River flows started increasing in late December, the Project would have implemented its 7-day pulse flow protection criteria and not started diverting until Jan. 3. The pulse flow protection criteria protects these initial high flow events as they provide value for outmigrating salmon and our river ecosystems.
Sites Reservoir is an off-stream reservoir that will capture and store a portion of stormwater from the Sacramento River and release water to California communities, farms, business, and wildlife during drier years. Sites Reservoir has broad statewide support from cities, counties, water agencies, and irrigation districts throughout the Sacramento Valley, San Joaquin Valley, Bay Area, and Southern California which are working together to advance the project. The Sites Reservoir Project is locally led by the Sites Project Authority which is made up Sacramento Valley water districts, cities, and counties.
