A new report by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) examined the headwater regions of California’s ten major reservoirs, representing half of the state’s surface storage, discovered each could experience a 79% decline in peak snowpack water volume by 2100.
Berkeley Lab used supercomputers to investigate current warming trends and carbon emissions.
Scientists analyzed how a future warmer world would affect “snowpack upstream of 10 major reservoirs — three in Northern California, three in Central California, and four in Southern California. The reservoirs are Shasta, Oroville, Folsom, New Melones, Don Pedro, Exchequer, Pine Flat, Terminus, Success, and Isabella,” said The Mercury News.
By 2039 to 2059, the snowpack runoff could drop by 54%, the study determined, and then 79% from 2079 to 2099. The study noted that three northernmost reservoirs, Shasta, Oroville and Folsom, could see an 83% reduction, by 2100.
Alan Rhoades, a postdoctoral fellow at Berkeley Lab and lead author of the study, said his team of researchers found that peak runoff could come four weeks earlier by 2100, at the beginning of March rather than April 01.
Mountain snowpack is a significant source of water for California: “Our precipitation is really intermittent and extremes-driven,” Rhoades said. “We get 50% of our annual precipitation in five to 15 days, or one to two weeks. Our water demand is highest during the summer months when we don’t get a lot of precipitation, so we really rely on mountain snowpack as a stopgap for our water supply.”
“So as the world continues to warm, these storms will get even warmer and won’t readily get to freezing, whereby you could have snowfall or snow accumulation and the persistence of snow on the surface,” he said.
As a result of warmer weather, the amount of snow is projected to decrease while rain could increase. The study noted that it did not look at rainfall, only mountain snowpack.
The study also found that snowmelt rates will decrease. The snow season which includes both the accumulation and melt portion of the season will fall by 20 days by 2050 and 39 days by 2100. This is primarily due to future weather systems will produce less snow but also because with the peak timing shifting to earlier in the year, the days are shorter and less energy from the sun is available to melt the snow.
Ellen Hanak, director of the Water Policy Center at the Public Policy Institute of California, has already begun to address the future water crisis in the state.
“Voters passed Proposition 1 in 2014, a water bond with $2.7 billion for new storage projects. This summer, state officials earmarked that money for eight projects, including raising the dam at Los Vaqueros Reservoir in Contra Costa County, building a new reservoir at Pacheco Pass in Southern Santa Clara County, building the massive Sites Reservoir in Colusa County, and several large groundwater storage projects in Southern California,” said The Mercury News.
Gov. Jerry Brown also signed a groundwater law that requires farmers and municipalities to better track groundwater usage.
Hanak said, “more projects are needed, such as efforts to pay farmers to flood their fields and orchards in wet years, recharging groundwater tables, along with far more recycled water projects, conservation efforts and other initiatives.”
“We have surface reservoirs, groundwater basins, and we have rivers and canals and aqueducts to connect them,” she said. “We’re going to have to manage them together more consistently.”
…And now it makes perfect sense: WSJ recently exposed Harvard University’s endowment (valued at $39 billion as of 2018), the largest academic endowment in the world, for quietly snapping up farmland and related water rights to properties located in the California region.
It seems like Harvard is establishing itself in the water brokering business, as the endowment’s money managers know they will make a killing when California runs out of the water.