The storms hitting California in February have left their mark on California's largest and most important water reserve.

Shasta Lake jumped 39 feet in elevation since February 1 and as of Tuesday it was at 85 percent of capacity and only 25 feet from its crest.

Amid a wet winter, dramatic lake level rises have been common this year. Folsom Lake east of Sacramento rose 30 feet in January, while Lake Oroville shot up 75 feet in February.

But for a reservoir the immense size of Shasta — you could put four and a half Folsom Lakes in Shasta — a 39-foot increase requires substantially more water.

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Shasta would likely be overflowing its rim, except the U.S. Bureau of Reclamation has released water this winter to prevent flooding and for environmental reasons.

On Wednesday, the bureau announced it will incrementally increase releases below Keswick Dam from 7,000 cubic feet per second to 25,000 cfs by 2 p.m. on Feb. 28.

Todd Plain, a spokesperson with the bureau, says, "This is very typical for these kinds of conditions. 79,000 cfs was the max release out of Shasta in 2017."

Plain adds: "We have a certain elevation height during the year and as the year progresses, we're able to hold more in our reservoirs. We try to hold onto as much water as we can can."

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With the release, levels on the Sacramento River are expected to rise below Keswick Dam and the bureau cautions the public to steer clear of the rising waterway.

With a capacity of nearly 4.5 million acre fee, Shasta is the state's third largest body of water after Lake Tahoe and the Salton Sea. It's an important link in the Central Valley Project, providing irrigation and municipal water to the Central Valley and flood control for the Sacramento Valley downstream of the dam. Water releases generate power through the Shasta Powerplant located just below the Keswick Dam.

In the gallery above, scroll through images showing California reservoirs in 2016 after several years of drought and in 2017 amid a wet year.

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