Monday July 1, 2024
San Francisco Chronicle —
Lake Oroville may be the largest state-run reservoir in California, but water officials just learned it’s not as big as they thought.
The California Department of Water Resources, during the 2021 and 2022 drought years, took advantage of the reservoir’s historically low levels to map the lakebed and discovered with the help of recently created 3D models that it’s about 3% smaller than advertised.
Starting Monday, the state will change its water supply calculations and reservoir operations to reflect the lake’s reduced water capacity: now 3,424,753 acre-feet instead of 3,537,577 acre-feet. (An acre-foot of water supplies at least two households for a year.) State websites and public information materials also will be updated.
State officials say Lake Oroville’s smaller size has a negligible impact on California water supplies. The reservoir, which provides at least some water to 27 million people, including many in the Bay Area, is one of several operated by the state Department of Water Resources. The lake is in Butte County in the northern Sierra foothills. In California, only the federally run Shasta Lake is larger.