California Reservoir Update as Water Levels Start to Fall

After peaking at full capacity earlier this year, Lake Oroville’s water levels have started their summer decline.

Newsweek reached out to the California Department of Water Resources (DWR) via email for comment.

Why It Matters

Lake Oroville, California’s second-largest reservoir, has experienced dramatic swings in water levels over recent years, reflecting broader challenges in the state’s management of water resources.

The summer of 2022 saw the reservoir drop to historically low levels due to prolonged drought, raising concerns about water supply for millions of Californians and extensive agricultural lands. However, winters of 2023 and 2024 brought above-average snowfall, leading to a strong rebound in reservoir storage and marking a period of unexpected recovery.

Although less snow fell this year, the lake reached its full capacity when the winter snowpack began to melt, supplementing its levels. This was the first time in the lake’s history that it reached full capacity three years in a row.

Lake Oroville is seen during a period of drought in 2022.

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What To Know

As of Monday morning, Lake Oroville’s water levels were at 896.46 feet in elevation. This is less than 4 feet below full capacity, which occurs at 900 feet.

Lake Oroville is expected to continue declining throughout the summer. Lake levels fluctuate throughout the year, with water levels typically beginning to rise when California’s wet season begins in the fall and continuing to do so throughout the spring, when snowmelt supplements the reservoir. Then, once snowmelt is complete and warmer temperatures move into the region, the lake levels begin to decline, typically starting around mid-June.

Lake levels are around 1 foot below the levels in mid-June 2024 and roughly 3 feet below the levels in June 2023.

Despite this, the lake remains at 98 percent capacity, according to California Department of Water Resources (DWR) data, which is 122 percent of the historical average for this time of year.

The return to such high levels followed periods of significant deficiency. During the height of the drought, water supplies from Lake Oroville for municipal and agricultural uses were threatened, exemplifying the volatility in California’s water system.

Officials noted that while the resurgence was a welcome development, it was primarily driven by the melting snowpack from unusually wet winters, and that not all regions in the Sierra Nevada—which feeds Oroville—enjoyed the same snowfall. In particular, while northern areas saw robust accumulation, central and southern regions lagged behind, resulting in regional disparities in recharge.

Despite the rebound, drought has persisted across much of California throughout the first half of the year. As of mid-June, about 60 percent of the state was classified as abnormally dry, with nearly 40 percent experiencing moderate drought conditions, most acutely in Southern California.

This dichotomy highlighted the delicate balance managed by the state’s interconnected system of reservoirs. Reliable water levels in Lake Oroville are crucial, as the reservoir supports the needs of urban, agricultural, and environmental sectors statewide, despite dramatic seasonal fluctuations in storage.

What People Are Saying

A DWR spokesperson told Newsweek earlier this month: “Lake Oroville is currently at full capacity. DWR is monitoring inflows and demands and will make adjustments to releases as needed. DWR continues to optimize water storage at Lake Oroville while meeting environmental requirements and allowing for carryover storage into next year.”

DWR Director Karla Nemeth, in a press release: “It’s great news that our state’s snowpack has recovered from several weeks of extremely dry conditions in the heart of our winter storm season. However, it’s not a wet year across the entire Sierra Nevada. The north has great snowpack, but snowpack is less than average in the central and southern part of the mountain range. That snowpack ultimately flows to the Delta, and the regional disparity affects how much water the State Water Project will be able to deliver.”