Despite recent rainstorms across the state, California’s historic drought shows no signs of abating any time soon.
In the absence of significant regular rainfall, the capacity of California’s reservoirs continues to decline, putting pressure on the state’s water supply.
Overall, nearly all major California water supply reservoirs managed by the California Department of Water Resources are well below historical averages.
The state’s largest water reservoirs, Lake Oroville in Butte County and Lake Shasta in Shasta County, are currently just below half of historical averages.
Shasta, the state’s largest reservoir with a capacity of 4,552,000 acre-feet of water, is currently at 31% capacity. Historically, capacity at Shasta Lake is typically around 57% at this time of year.
Lake Oroville, which has a capacity of about 3,537,000 acre-feet of water, is in an even more difficult situation. As of November 14, Oroville was at 29% capacity, nearly half the historical average of 58%.
An acre-foot is approximately 326,000 gallons.
While the state’s largest reservoirs are already at shockingly low levels, a handful of smaller water supplies are even drier.
Pine Flat Reservoir in Fresno County has the lowest capacity of reservoirs in the state, at just 16 percent. With a maximum capacity of 1 million acre-feet of water, Pine Flat currently only holds about 160,000 acre-feet.
Lake McClure in Mariposa County is currently at 18% of its capacity of 1,024,600 acre-feet. Historically, at this time of year, the reservoir is typically around 42% capacity.
Trinity Lake is the third lowest reservoir in the state with a capacity of 22%. The Trinity County Reservoir has a capacity of over 2,447,000 acre-feet and is historically at 38% capacity at this time of year.
The San Luis, Casitas, Folsom, and Sonoma reservoirs are all about 25% capacity and contain about half of what they historically contain at this time of year.
For an interactive list of reservoir capacity levels managed by the California Department of Water Resources, click here.
According to CalMatters, statewide reservoir storage fell 69% below average at the end of September due to the driest three-year period in US history. State.
With Governor Gavin Newsom and water resource managers calling for continued water conservation, California’s reservoir capacity will be something to watch as winter approaches — a winter that the National Oceanic and Atmospheric Administration expects to be “drier” for parts of the state.