Reservoir peaks at only half capacity
Lake Oroville, the largest reservoir in a state system that provides water to 27 million Californians, has reached its peak level for the year, barely surpassing half of its capacity, according to the Department of Water Resources.
Officials had warned May 8 that the lake — key to the roughly 700-mile State Water Project, which pumps and ferries water across the state for agricultural, business and residential use — was at “critically low” levels.
Those levels, data from the Department of Water Resources now show, were the reservoir’s highest for the year.
On May 8, Lake Oroville crested at 1.94 million acrefeet. As of Monday, it had dropped to 1.81 million acrefeet. The reservoir can hold 3.54 million acre-feet of water, almost double the current level.
State officials said the lake was at 51% of capacity and 66% of its historical average for this point in the year.
Though well below historical levels, the reservoir has shown improvement over last year, when drought forced the hydroelectric power plant that relies on Lake Oroville’s water supply to shut down. This year’s peak water level was about 400,000 acre-feet above 2021’s highest point, Department of Water Resources data show.
Until 2021, water levels for the lake north of Sacramento had peaked at 2.5 million or more acre-feet every year since 2015.
The Department of Water Resources forecasts that Lake Oroville’s level will continue to fall through the end of the year, but the agency said it does not expect that the hydroelectric power plant will need to shut down.
Despite California’s below-average precipitation this year, Lake Oroville benefited from October’s “record-setting atmospheric river,” the department said.
Snowfall in December also helped, but the driest January, February and March of this century left Oroville with “below average storage for the season,” according to the department.