How much water is in Lake Shasta, California reservoirs in 2026?

Lake Shasta and California’s other lakes and reservoirs got a big boost from wet holiday storms. Nearly two weeks into 2026, all of the state’s 17 major reservoirs are brimming above their 30-year average after atmospheric rivers dumped heavy rain on much of the state starting the week before Christmas, lasting into Wednesday, Jan. 7.

Both the rain and the rainwater draining from the ground into lakes helped raise reservoir levels, the National Weather Service said.

Lake Shasta waters lapped just short of 29 feet from the top on Jan. 11, after rising about 45 feet since Dec. 18 — the day before the first heavy winter storm of the season rolled over Shasta County, according to the California Department of Water Resources.

Two other major Southern California supply reservoirs were full or near full as of Jan. 11, according to state data.

• Lake Cachuma is 101% full. The reservoir contained 58% more water than its 30-year historic average.
• Lake Casitas is 98% full, 27% more than its average.

Lakes continue to fill for days after storms pass as the heavily saturated soil continues to drain into waterways, said meteorologist Bill Rasch at the weather service’s Sacramento branch.

Based on state water resources department reports, here’s how much water other major reservoirs held on Jan. 11, starting with the three biggest.

How full is Lake Shasta?

Lake Shasta, the biggest state-owned reservoir, was 82% full, according to the state’s latest data. With several months left to go in the area’s rainy season, the lake was 35% more full than its historic average over the past 30 years.

However, Lake Shasta started the water year 4% higher than average on Oct. 1, 2025, after Northern California’s super wet spring.

How full is Lake Oroville?

The state’s second-largest reservoir, Lake Oroville — located 80 miles north of Sacramento in the Sierra Nevada foothills — was 78% full and held 39% more water than usual on Jan. 11.

Oroville also started the water year with an advantage: It was 7% more full than usual on Oct. 1.

How full is Trinity Lake?

Another far Northern California reservoir and the state’s third largest, Trinity Lake, was 84% full and held 38% more water than usual.

It’s the second year in a row that the lake has shown healthy water levels. Trinity’s waters plummeted over several years of drought, dropping to to 40% of its historic average in January 2023.

While only about 25 miles northwest of Lake Shasta, Trinity fills more slowly over the calendar year and requires more time to recover after drought than its counterpart, the Bureau of Reclamation has said.

How much water is in 12 other California lakes and reservoirs

Here’s how much water is in 12 other major state reservoirs a week into 2026, according to water resources department data, and how much more water they contain compared to their historical average on Jan. 11.

• New Bullards Bar (40 miles northeast of Marysville in Yuba County): 82% full, 29% more than average
• Folsom Lake (25 miles east of Sacramento): 60% full, 41% more than average
• Camanche Reservoir (45 miles southeast of Sacramento): 73% full, 22% more than average
• Lake Sonoma (30 miles north of Santa Rosa): 70% full, 21% more than average
• San Luis Reservoir (70 miles east of Santa Cruz): 73% full, 9% more than average
• New Melones Reservoir (55 miles east of Stockton on the Stanislaus River): 73% full, 29% more than average
• Don Pedro Reservoir (45 miles east of Modesto): 80% full, 17% more than average
• Castaic Lake (45 miles north of Pasadena): 78% full, where it stands on average
• Lake McClure (50 miles east of Modesto): 69% full, 52% more than average
• Diamond Valley Lake (40 miles southeast of downtown Riverside): 94% full, 30% more than average
• Millerton Lake (20 miles north of Fresno): 77% full, 40% more than average
• Pine Flat Lake (35 miles east of Fresno): 45% full, 24% more than average

Jessica Skropanic is a features reporter for the Record Searchlight/USA Today Network. She covers science, arts, social issues and news stories. Follow her on Twitter @RS_JSkropanic and on Facebook.