A series of atmospheric river storms since Christmas has significantly reduced California’s drought, the federal government concluded Thursday.
For the first time in more than two years — since Dec. 1, 2020 — the majority of the state is no longer in a severe drought, according to the U.S. Drought Monitor, a weekly report put out by the National Oceanic and Atmospheric Administration, the U.S. Department of Agriculture and the University of Nebraska-Lincoln.
Overall, 46% of California’s land area remains in severe drought, the report found, a dramatic improvement over the past month, when it was 85% on Dec. 6.
“Intense precipitation in California the past few weeks particularly late December and early January has significantly reduced drought intensity in California,” wrote Richard Tinker, a meteorologist with the NOAA’s Climate Prediction Center in College Park, Maryland.
The last time California had no land area at all in severe drought was nearly three years ago, on March 10, 2020, after a disappointing winter rain and snow season that year began a three-year arid stretch.
Gov. Gavin Newsom declared a drought emergency the following spring, on April 12, 2021 for Mendocino and Sonoma counties, where reservoirs had fallen to parched levels and water shortages were emerging. He expanded it to 41 counties the following month, and statewide by October, 2021, urging California residents to cut water use 15%.
While Newsom has not ordered mandatory city-by-city water conservation targets with fines for cities that fail to meet them, as former Gov. Jerry Brown did during the 2012-17 drought, last year Newsom did require all major water providers in the state to impose their “stage 2” drought rules, which limited the number of days people could water lawns and set other restrictions that varied by community.
When Newsom made the first drought declaration nearly two years ago, 85% of California was in severe drought, according to the Drought Monitor — almost double the level now.
Since late December, the weather, and California’s drought outlook, has shifted dramatically. California has been hammered by six atmospheric river storms since Christmas. They have caused flooding in coastal areas and the Sacramento Valley, and sent the Sierra snowpack to 226% of its historic average.
Every week, the Drought Monitor report uses soil moisture, rainfall totals, snow, reservoir levels and other factors to rank parts of the United States in drought severity on a scale of 1 to 4, with 1 being moderate drought, 2 being severe drought, 3 being extreme drought and 4 being exceptional drought.
In recent weeks, coastal areas and the Sierra Nevada have received so much precipitation that they have improved to the lowest drought category, moderate drought. That includes most of the Bay Area, which was in severe drought just a month ago.
The heavy rains have filled smaller reservoirs in many communities. All seven of the Marin Municipal Water District’s reservoirs reached 100% capacity this week, as did four of the 10 owned by the Santa Clara Valley Water District, while the seven run by the East Bay Municipal Utility District are 84% full. Hetch Hetchy, the main reservoir on San Francisco’s water system, was 79% full on Wednesday, or 120% of its historical average.
State and federal officials have welcomed the rain and snow. But they have cautioned in recent days that the drought is not year over, because the largest reservoirs in California, which fell to dangerously low levels last summer, are not yet full.
The largest, Shasta Lake, near Redding, was 44% full on Wednesday, 77% of its historical average for that date, and slowly but steadily rising. The second largest, Oroville, in Butte County, was 49% full, or 90% of the historical average, having risen 97 feet since Dec. 1.
Last year a very wet December raised hopes the drought was ending, only to be followed by the driest January, February and March in recorded California history, leaving the Sierra snowpack at just 37% at the end of last winter on April 1.
State and federal water managers said this week that they need to see how much the reservoirs continue to fill around the state, whether the storms shut off and how local water supplies, including depleted groundwater, improve, and how the snowpack continues to change before declaring an end to the drought.
“We will be reassessing in the later part of January what this means relative to overall drought,” said Karla Nemeth, director of the state Department of Water Resources, on Monday.
She hinted that if conditions continue to improve, Newsom may lift the drought emergency regionally, rather than statewide all at once.
“By and large, most of our reservoirs continue to be below average,” Nemeth said. “The governor declared drought emergency a couple of years ago. He did so in certain parts of the state, and as the drought deepened and spread throughout California, that drought emergency was extended. Typically when we move out of drought emergency we follow the same format. There’s a lot of variability across California, in terms of not just hydrologic conditions but water supply availability.”
Last week, 27% of the state, nearly all in the Central Valley, was mired in level 3, or extreme drought. Now less than 1% of California is, a tiny sliver of land near the Oregon border in Modoc and Siskiyou County. The last time so little of California was in extreme drought was April 14, 2020.
Tinker, in writing the weekly Drought Report, cited some of the stunning weather changes over the past week in California.
He noted that on Monday, Bishop, in the Eastern Sierra, reported 3.02 inches of rain, which was the fourth wettest day in at least 71 years there. The city’s winter rainfall total of 6.8 inches is more than 4 times normal.
Since Dec. 1, downtown Sacramento reported 14.25 inches of precipitation, three times the historical averge of 4.76 inches. The 16.10 inches received of rain by Oakland since Dec. 1 is also triple the historical average. And farther south, Santa Maria in Santa Barbara County reported 10.61 inches of rain since Dec. 1, compared to a normal of 2.96 inches.
