Storms starting to fill California’s drought-parched reservoirs

Tori Gaines

2 years ago

In an aerial view, water flows down the spillway at Nicasio Reservoir after days of rain have brought the reservoir to near capacity on January 09, 2023 in Nicasio, California. The San Francisco Bay Area and much of Northern California continues to get drenched by powerful atmospheric river events that have brought high winds and flooding rains. The storms have toppled trees, flooded roads and cut power to tens of thousands. (Photo by Justin Sullivan/Getty Images)

After weeks of atmospheric rivers, bomb cyclones and Pineapple Express moisture, California reservoir levels have seen a steep rise.

On Sunday, the National Weather Service shared an infographic from the Department of Water Resources, which laid out just how much California’s reservoirs have filled after weeks of heavy rain.

While none of the major reservoirs are at capacity – in fact, many are still less than half full – many are at or above their historical average for this point in the rainy season. Oroville, for example, is at 54% capacity, but 99% of where it usually is in mid-January.

But three years of drought has left the state begging for more water. Experts say it will take more than a few weeks of rain to fix California’s long-term water problems.

Reservoir levels are measured using acre-feet, or AF, a common measurement for water. One acre-foot equals about 326,000 gallons, according to the Water Education Foundation.

Northern California

Reservoirs in NorCal have been at lower levels over the past year, with Shasta reservoir sitting at 29% of capacity in November 2022. Shasta was under 1.5 million AF on Jan. 1, but, in the past two weeks, over 700,000 AF of water has been dumped into the reservoir.

Shasta — 49% of capacity, 80% of historical average
Trinity — 29% of capacity, 47% of historical average
Sonoma — 57% of capacity, 99% of historical average
Oroville — 54% of capacity, 99% of historical average
New Bullards Bar — 78% of capacity, 122% of historical average
Folsom — 47% of capacity, 110% of historical average

(Photo courtesy of Dept. of Water Resources)

Central California

Reservoirs across Central California were some of the driest in the past year. The Pine Flat reservoir near Fresno was at a shockingly low 16% of total capacity in November 2022. Pine Flat more than doubled its water levels since the start of 2023. On Jan. 1, the reservoir started with just over 200,000 AF, but after two weeks of storms is now sitting at 440,784 AF.

Camanche — 73% of capacity, 122% of historical average
New Melones — 36% of capacity, 64% of historical average
Don Pedro — 72% of capacity, 103% of historical average
McClure — 50% of capacity, 110% of historical average
Pine Flat — 44% of capacity, 119% of historical average
Millerton — 82% of capacity, 148% of historical average
San Luis — 43% of capacity, 63% of historical average

(Photo courtesy of Dept. of Water Resources)

Southern California

Though some SoCal reservoirs are still at low levels, Cachuma Reservoir, located in Santa Barbara County is only 16% below capacity, and is 30% higher than it has been on the same date historically.

Cachuma — 84% of capacity, 130% of historical average
Casitas — 37% of capacity, 51% of historical average
Castaic — 54% of capacity, 70% of historical average
Diamond Valley — 61% of capacity, 84% of historical average

The precipitation has been welcomed across drought-ridden California, but with it has come flooding, mudslides and downed trees across the state. According to meteorologists with KTLA sister station KRON4, the wet weather should take a break by the third week of January, or next week.

Data measuring reservoir levels is available on the Dept. of Water Resources website, along with historical average levels for this date for each of the reservoirs.