LOS ANGELES — The drought-dried shores of Folsom Lake were damp this week after what officials called the first big storm of the season.
The water level at Lake Oroville, which receded so much this summer that officials had to close its hydroelectric power plant for the first time, rose by more than 16 feet.
And the Russian River — recently reduced to something more like a trickle — flowed with more ease after the atmospheric river dumped record-breaking amounts of rain across California, replenishing dwindled reservoirs and rehydrating cracked terrain.
Despite the mayhem the atmospheric river caused for some residents, the historic storm marked a welcome change for a parched California after a year of heat and drought with so little rain.
“If we could have designed a storm it would have been this one,” said Emma Detwiler, a spokeswoman for the Marin Municipal Water District, which saw its depleted reservoirs grow from 32% capacity to 43% during the storm. “It’s a great step in the right direction.”
But while the massive plume of moisture helped, experts said it will take much more than one storm to make a dent in the drought. The 2021 Winter Outlook recently released by the National Oceanic and Atmospheric Administration found that dry conditions are likely to persist across much of the West through at least the start of next year.
“It’s been very, very dry for two years,” said Jay R. Lund, director of the UC Davis Center for Watershed Science. “One storm does not end that kind of a drought.”
The fast-moving storm shattered several records as it moved through the state Sunday and Monday. Downtown Sacramento saw a record 24-hour rainfall total of 5.44 inches, surpassing a mark set in 1880, the National Weather Service said.
City officials said the precipitation totals represented even more than a “200-year storm level,” which occurs at 4.6 inches and has only a 0.5% chance of occurring in any given year.
Placer County’s Blue Canyon received 10.4 inches of rain — breaking its previous record from 1964.