After five years of drought, could California really have so much rain and snow there’s no room to store all the water?
The answer – as the state’s water picture careens from bust to boom – is yes.
One month into an exceptionally stormy 2017, river flows though the Sacramento-San Joaquin Delta have been so powerful that the massive pumps that ship north-state water to Southern California and the San Joaquin Valley have roared at full throttle for weeks. The federal and state pumping stations near Tracy delivered more water in January than in any month in the last 12 years, according to a Sacramento Bee review of data supplied by the U.S. Bureau of Reclamation.
With more rain and snow in the forecast, the pumps could stay at capacity for the next week or two. But pump operators probably will have to dial back because they’re starting to run out of space in key reservoirs south of the Delta, said John Leahigh, who oversees day-to-day water management for the State Water Project, which delivers supplies to water agencies throughout California.
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“This is definitely a 180 that we’ve done in terms of water supply,” Leahigh said.
Thursday brought more news of California’s progress against what has been a withering drought. Snow surveyors found a whopping 90 inches of snow at Phillips Station, a long-standing measuring spot near Echo Summit. That translates into 28.1 inches of “snow-water content,” a leap of 22 inches in a month. The Phillips snowpack is at 153 percent of historical average and sits at its highest measurement for early February since 2005.
Frank Gehrke, the veteran Department of Water Resources official who runs the snow survey, said the strong results reflect the heavy precipitation that fell in January, which was “pretty much a banner month in terms of the snowpack.”
Across the entire Sierra Nevada, the results were even more impressive: Snow-water content stood at 173 percent of historical average. Many spots have as much snow as they typically have on April 1, when the snow season peaks. A healthy snowpack means extra water becomes available in summer, when lawns and crops get thirsty in California’s arid central and southern expanse and demand soars.
“Basically, a seasonal snowpack (is) already on the ground,” Gehrke said. “And February and March quite often have very good storm activity.”
With the exception of Folsom Lake, which is being kept below its historical average levels to meet flood-safety requirements, many of California’s reservoirs are filling up quickly.
Leahigh said all the water gushing from the Delta pumps soon should fill San Luis Reservoir west of Los Banos – one of the largest reservoirs in the state and a linchpin of south-of-Delta water supplies. San Luis, which is twice the size of Folsom Lake, is 84 percent full and rising. Before long, it won’t be able to take any more water, according to Leahigh. Almost all of its water is pumped in from the Delta.
The reservoir’s ample supply is a remarkable turnaround from last summer, when San Luis plummeted to its lowest levels in a quarter century. Some Silicon Valley cities that draw drinking water from the lake feared shortages and warned customers of foul tastes and smells from the algae blooms forming on the lake’s low, gunky surface.
Officials said the increased pumping stems in some part from a controversial water bill signed into law last year by then-President Barack Obama. The law directs operators of the Delta pumps to “maximize water supplies for the Central Valley Project and the State Water Project” by essentially shipping as much water south as is allowable under the Endangered Species Act.
But the primary reason so much water is being pumped is the vastly improved hydrological conditions in the Delta, particularly in the watersheds that supply the San Joaquin River. More than the Sacramento River, the flows on the San Joaquin are critical to how much water can be pumped.
“What is really driving the system is the amount of water flowing down the San Joaquin River into the Delta,” said Doug Obegi of the Natural Resources Defense Council. He said pumping has been increased without violating protections for endangered fish.
The massive pumps in the south Delta, built decades ago along the San Joaquin side of the estuary, are so powerful that they can actually reverse the flows of key San Joaquin channels. That can draw smelt and other fish toward the pumps and predatory fish that await them at the intakes.
Last winter, storms brought powerful currents to the much larger Sacramento River. But pumping was nonetheless restricted because government biologists were concerned for the safety of endangered fish species that were migrating close to the pumps. That brought protests from south-of-Delta water agencies and their political supporters, including Sen. Dianne Feinstein, D-Calif., who said too much water was being allowed to flow to the ocean.
This year, the San Joaquin is running four times stronger than last year, more than enough current to counteract the powerful “reverse flows” generated by the pumps – even with both state and federal pumping facilities operating at full capacity, said Louis Moore, a spokesman for the U.S. Bureau of Reclamation, which operates the federal pumping plant.
“It is a totally different world than a year ago,” said Jason Peltier of the San Luis and Delta-Mendota Water Authority, one of the major suppliers of water to Silicon Valley and San Joaquin Valley farmers.