A recent barrage of winter storms helped save much of California from years of drought, but the state is facing flooding and continued groundwater shortages that may occur in the coming months. I have it.
This time last year, the entire Golden State was dealing with drought.now almost 64 percent There is no drought this season after a series of “atmospheric rivers” flooded much of the region with rainfall and mountains of snow across the Sierra Nevada.
The improvement has been so dramatic that even the Metropolitan Water District of Southern California moved this week cancel All water usage restrictions.
According to the National Oceanic and Atmospheric Administration (NOAA), “an unusually wet winter will further improve drought conditions in much of the western United States as the snowpack melts in the coming months.” proclaimed that spring Outlook this week.
These conditions “wiped out an exceptional and extreme drought in California for the first time since 2020,” with further progress expected this spring, the agency added.
However, this influx of water also comes with many challenges, such as the risk of dangerous flooding and the need for improved methods of filling depleted groundwater reservoirs.
“Now that we’re out of the drought, with so much snow on the mountains, and the threat of flooding, there’s obviously a lot of interest in getting rid of as much of this water as possible,” said Davis, California, Hill. told to
According to NOAA, this spring’s thaw could lead to “a welcome water supply advantage” in much of California and the Great Basin, boosting major Colorado River reservoirs.
But flooding has already begun to hit the western United States, and conditions could get worse this spring as snowpacks in the Sierra Nevada melt in already saturated soil, according to NOAA.
“California’s historic snowfall, combined with spring rains, increases the likelihood of spring flooding,” said Ed Clark, director of NOAA’s National Water Center, in a statement.
And California isn’t the only state that could face flooding. “About 44% of the U.S. is at risk of flooding this spring,” Clark said.
According to NOAA, most of the eastern half of the continental United States will experience moderate to severe flooding along the Mississippi River, with flood risk likely to occur in the coming months.
According to Daniel Swain, a climate scientist at the University of California, Los Angeles, California is currently experiencing major flooding in two regions: the Salinas Valley and the southern Sierra Nevada.
The Salinas Valley, where recent rains breached the banks of the Pajaro River, is one of the most productive agricultural areas in the state.
“This is really devastating for these communities and will probably have a big impact on the agriculture coming out of the Salinas Valley for a while,” Swain said. between vactual office hours on friday.
Meanwhile, in the southern Sierra Nevada, prolonged snowmelt at lower elevations has filled the region’s small reservoirs. This “means that water is flowing out about as fast as it is coming in,” he says Swain.
He warned that this water is draining into the foothills, especially the San Joaquin Valley, another important agricultural region adjacent to the Salinas Valley.
“This is not going to end in the next few days.
Meanwhile, this winter’s heavy rainfall challenges states to optimize their storage capacity, especially as groundwater reserves remain low.
Harter of the University of California, Davis described the “spatial disconnect” between mountainous regions, where most precipitation occurs, and valley floors, where most water users are.
“Most of the water falls off in the winter and you really need most of it in the summer, so there’s a time lag,” he said.
Effective storage and transportation schemess So, according to Herter, it’s important to fill those gaps.
He described three types of natural reserves that can be replenished in one season.
But a fourth type of reservoir, a groundwater reservoir, needs a much longer time to fill with water, he explained.
“At least one normal or wet year is needed to compensate for the extra withdrawal from the groundwater in the dry year,” says Harter.
Over the past 25 years, he has consistently had 9 average or wet seasons and 16 dry seasons, creating budget imbalances.
However, stressing that it is possible to accelerate the groundwater recharge process, Harter applauded the recent push of various related policies by the California state government.
For example, earlier this month, the California Department of Water approved the petition From the Federal Reclamation Service to divert over 600,000 acre feet of San Joaquin River floodwaters to storage, recharge, and wildlife sanctuaries.
“We need to charge more,” Harter said. “It’s like a bank account. Either you earn more, or you spend less from your account.”
California may need to get ready to inject more into its accounts as El Niño conditions begin to materialize this summer, with three consecutive years of La Niña coming to an end, according to the NOAA Spring Outlook.
El Niño typically brings hot, dry conditions to the northern United States and Canada, Increased flooding on the Gulf of MexicoSoutheast and parts of California, according to NOAA’s National Ocean Service.
Consistent with these patterns, NOAA’s Spring Outlook predicted extreme to exceptional drought to persist in the southern High Plains, the northwestern United States, northern Rocky Mountains, and parts of New Mexico and Washington.
“There is now a fairly strong projection that we are headed into El Niño territory,” Swain said, describing the “sudden change” from cold to “very warm” temperatures in the eastern Pacific.
“From late 2023 to 2024, global average temperatures are expected to be the highest ever seen, but not exceeded.”
Swain stressed that it’s still too early to speculate what this means for California, saying a strong El Niño event is likely, along with “a very active wet winter next year.” Stated.
Years of record-breaking drought are currently providing “a little buffer in terms of flood risk,” but next year there will be no such barrier, he explained.
“This year’s legacy of very wet conditions, especially very heavy snowpacks, will probably last all summer,” Swain said.
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