Here’s Why Water Officials Began Releasing Water Out of Lake Oroville
An eye-catching surge of water pouring down the Oroville Dam spillway this week wasn’t just for show, it was a required move as Northern California’s wet season rapidly refilled Lake Oroville.
Officials with the California Department of Water Resources began releasing water from the state’s second-largest reservoir as part of routine winter flood-control operations. Between October and spring, Lake Oroville is managed to maintain enough empty space to safely absorb incoming rain and snowmelt, reducing flood risk for downstream communities.
After a slow start to December, a series of atmospheric river storms drenched Northern California beginning mid-month. The impact was swift. In just over two weeks, Lake Oroville’s water level jumped 58 feet, forcing managers to activate the dam’s main spillway to stay ahead of rising inflows.
As of the latest DWR data, Lake Oroville sits at 76% capacity—about 138% of its historical average for this time of year. Even with ongoing releases, the lake continued climbing, reaching roughly 842 feet in elevation, about 17 feet higher than the previous week. Inflows were projected between 50,000 and 70,000 cubic feet per second, while releases held near 15,000 cubic feet per second—more than 9.6 billion gallons per day.
DWR officials say some of that released water is captured downstream for local use and the State Water Project. Other reservoirs are also benefiting from the storms, including Lake Shasta, which rose more than 35 feet in recent weeks.
Together, California’s major reservoirs are now holding well above seasonal averages, offering a strong buffer as winter continues.
