Recent Storms Boost Reservoir Storage, but South State Lags Behind

Drenching rains have restored key Northern California reservoirs to historic averages, but Southern California has largely missed out and water storage south of the Delta remains low, state and federal water managers said in an update to the State Water Resources Control Board on March 15.

While the recent storms are “encouraging” and have sent large volumes of water into rivers, streams and reservoirs, officials are not ready to declare a “March Miracle” that will lift the state completely out of drought.

State Water Resources Control Board Chair Felicia Marcus expressed cautious optimism about improved conditions, and said the State Water Board would revisit its 2016 emergency drought regulation later this spring.

“I think we are feeling better with the encouraging march storms,” Marcus said at the March 15 meeting. “We still need to wait and see what March brings and April brings. Then we can figure out how to adjust our regulation.”

The regulation, adopted Feb. 2, extends mandatory urban conservation requirements through October with a few limited adjustments to reflect climate, growth and development of some drought-resilient supplies since 2013. The State Water Board was directed at that time to evaluate conditions and revisit the regulation by May 1.

Storms a Boon to North State Storage

State officials are forecasting a storage gain of about 5 million acre-feet of water by the end of March, which would boost statewide storage to about 84% of average by month’s end.

As of March 15, Shasta, Oroville and Folsom reservoirs in North California had reached 100% or more of historic average. Lake Shasta was encroaching on flood control space. By comparison, San Luis Reservoir south of the Delta was at 54% of historic average, New Melones was at 36% of average and Don Pedro 73%.

John Leahigh, water operations chief for the Department of Water Resources, said the department is recalculating runoff forecasts for the Sacramento River and the San Joaquin River as a result of the recent rains, and expects to issue updated allocations for the State Water Project in the coming days. The department issued an initial allocation of 15% of requests in January, and increased it to 30% on Feb. 24.

The Bureau of Reclamation is expected to announce Central Valley Project allocations in mid- to late March.

Leahigh noted that the projects have been pumping at about half of their capacity in the Delta due to water quality standards and requirements to protect species. He indicated that officials hope to release and utilize stored water in Shasta and other reservoir for export during the dry summer months.

“That is something that was not available last year,” Leahigh said.

Photo: Oroville Reservoir / Department of Water Resources