Drought Year State Water Project Operations – April 2021 This graphic illustrates a moment in time, storage to meet public health and safety while water project operations are evolving needs. Operators are making minimum constantly based upon the interplay of releases necessary to primarily 1) runoff, temperatures, demand for water, supply senior water-right holders in the and many other factors. Sacramento Valley who have first rights to Lake Oroville is the largest reservoir of the Feather River flow and 2) repel salty tides State Water Project, which supplies water so that water exported to cities and farms to 29 public water agencies serving more south of the Delta via State Water Project than 27 million Californians. pumps remains fresh. Lake Oroville last filled in 2019. The current Increased releases from Lake Oroville historically low State Water Project water would further reduce storage needed supply allocation is primarily due to later in the season for health and safety extremely dry conditions that have occurred purposes. over the past two years. This year the South of the Delta, San Luis Reservoir is Sacramento Valley runoff is the third driest currently at 58 percent of average for the in the historical record. date. The State Water Project share of the Lake Oroville storage is trending toward storage is 640,000 acre-feet. 900,000 acre-feet at the end of August, State Water Project operators are using likely falling below the 1977 historic low Delta and California Aqueduct facilities of 880,000 acre-feet in late summer or to help water districts cope with low early fall. allocations by facilitating water transfers Next winter may be dry, too. Lake Oroville and moving water withdrawn from currently is being operated to conserve south-of-Delta groundwater storage banks.