Despite erratic bursts of precipitation since October, snowpack on April 1 was the fifth-lowest on record since 1950, state climatologist Michael Anderson said. It sits at just 22 percent of average as of May 10.
“We used to get these monster snowpacks above 200 percent of average – the last one was in 1983,” Anderson said Tuesday. “Since then, they haven’t made an appearance.”
While the reality of the drought – and climate change – may be apparent in parched reservoirs and disappearing mountain snow, that hasn’t quelled the demand for water. Gov. Gavin Newsom (D) called on Californians to voluntarily reduce water use by 15 percent last summer, but it declined by only 3.7 percent from July through March compared with the same period in 2020, according to the State Water Resources Control Board.
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It remains to be seen how well the state can conserve existing supplies through the long, hot summer months ahead.
Major reservoirs depleted
Snowpack and snowmelt peaked early this year, and the wet season is drawing to a close.
According to the latest water supply forecast from the Department of Water Resources, runoff in the state’s watersheds is well below average, signaling that reservoirs won’t get much of a boost from further snow melt.
“This is what we have; This is what we’re going to get – we can’t expect anything significant past this date, “said Jeanine Jones, interstate water resources manager for the department.
Lake Oroville, the backbone of the State Water Project, which supplies water to farms, homes and businesses statewide, is only 55 percent full. Shasta Lake, the state’s largest reservoir, is only 40 percent full and is approaching record-low levels for the time of year, while the nearby Trinity Lake is at only 31 percent of its total capacity.
The Colorado River is an important water source for Southern California, but it is depleted by a climate-change-intensified megadrought – the worst in 1,200 years – as is much of the West. California has senior water rights on the river and has conserved and “banked” water in Lake Mead for future use.
But supply from the massive Colorado River reservoirs isn’t guaranteed in the era of climate change.
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“This has been the mainstay in terms of reliability for California during droughts,” Jones said. “When we’re looking forward, we see an increased risk of a first-ever shortage to California because of the conditions in the Colorado River Basin.”
“This is really an indication that Mother Nature is reminding us that we are in a world of climate change, it’s here, and we need to start adapting to it,” she said.
Relentless heat is already driving the West toward more intense drought by pulling moisture from the land surface via evaporation – drawing down water supplies and increasing wildfire risks. A recent study found widespread increases in atmospheric thirst driven mostly by rising temperatures due to human-caused climate change.
“These higher evaporative demands mean that, for every drop of precipitation that falls, less water is likely to drain into streams, wetlands, and aquifers across the region,” the study notes.
Farms and cities also use more water during hot weather. Marielle Rhodeiro, a research data specialist with the California Water Resources Control Board, reported Tuesday that urban water use rose by nearly 19 percent in March 2022 compared to March 2020, partly because of warmer and drier conditions this year.
A report by the Public Policy Institute of California (PPIC) found that high temperatures in 2021, which were nearly 3.5 degrees Fahrenheit above average, resulted in an 8 percent increase in crop water demands.
“We are seeing increased evaporative demand that is making our region thirstier, and we’re having less water available because of that,” said Alvar Escriva-Bou, a senior fellow at PPIC’s Water Policy Center. “We are not yet considering this in planning and management, so this is something that we need to account for.”
On April 26, the Metropolitan Water District of Southern California announced unprecedented restrictions for 6 million customers who rely on water delivered from Northern California via the State Water Project. The move requires households to limit outdoor watering to one day per week starting June 1; A full ban on watering could be imposed by September if the region fails to adequately reduce its water use.
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“This is a crisis unlike anything that we’ve seen before,” said Deven Upadhyay, chief operating officer for the district, when the restrictions were announced. “We really only have a little more than half of the water that we need to be able to make it through the summertime and into the end of the year under normal demands.”
Escriva-Bou said two-year droughts are relatively normal in California, but 2020 and 2021 were exceptionally hot and dry – a difficult lead-in for 2022.
“The situation this year is going to be much worse than last year,” he said. “The cumulative impact of a third year of drought makes it much more difficult to manage.”