California’s Largest Reservoir Rose to 77% Capacity After Recent Rains

Almost all of the state’s reservoirs are nearing capacity after significant storms passed across the state.

1 minute read

January 7, 2026, 7:00 AM PST

By Diana Ionescu @aworkoffiction


Shasta Dam with deep turquoise water in reservoir behind it in northern California.

Like other reservoirs around the state, Lake Shasta received a major boost in its water supplies over recent weeks. | Wirestock Creators / Shutterstock

Lake Shasta, California’s largest reservoir, us up to 77 percent capacity after last weekend’s rains, rising 36 feet since December 16.

As Paul Rogers explains in The Mercury News, “Similarly, the water level at Oroville, the state’s second-largest reservoir, in Butte County, has jumped 69 feet over the same three weeks. On Monday, it was 73% full and at 134% of its historical average, having added nearly as much water in the past 24 hours as Crystal Springs Reservoir in San Mateo County holds when full.”

The Sierra Nevada snowpack, down to 18 percent of normal on December 16, was up to 90 percent on Monday as skiers celebrated the fresh powder. 

California typically receives most of its rain between December and March, so more wet weather could be on the way. “In Southern California, Cachuma Reservoir, the largest in Santa Barbara County, was 100% full and spilling on Monday. Farther south, Diamond Valley Lake in Riverside County, a linchpin of the water supply for 20 million people in the Los Angeles region, was 94% full.”

Monday, January 5, 2026 in The Mercury News

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