Checking in on California Water, Snow Levels
We are now midway through our typical water year when it comes to rain and Sierra snow.
We are now midway through our typical water year when it comes to rain and Sierra snow.
The Santa Ana winds that led San Diego Gas & Electric to shut off power to more than 5,900 customers on Tuesday are now reaching their peak and come amid dangerously low relative humidity across critically dry San Diego County, the National Weather Service says.
“Old superlatives have been dusted off and new ones count to better describe the tragedy, damage, and trauma associated with the State’s latest ‘unusual’ weather experience.” DWR Bulletin 69-83, California High Water 1982-83, p.1
The allure of California has long been its almost unbelievably good weather: predictably dry summers and pleasant, if occasionally rainy, winters. Who wouldn’t want to escape swampy heat for this temperate paradise? Our typically agreeable weather (current heat wave notwithstanding) is officially called a Mediterranean-type climate, defined as having cool, wet winters and dry, warm summers.
To visualize the hellishness of the climate crisis in 2021, look no further than General Sherman, the world’s largest tree, wrapped in fire-resistant foil to protect the legendary giant sequoia from flames burning a path of destruction through the Sierra Nevada.
California’s so-called Ancient Ones evolved with fire. It’s crucial to their reproductive cycle. But they aren’t prepared for blazes like those of the last year, which are burning hotter and more intensely as Earth warms, mostly because of the combustion of fossil fuels. Last year, flames killed roughly 10% of the world’s giant sequoias.
The Senate Rules Committee last week unanimously approved Gov. Gavin Newsom’s reappointment of Joaquin Esquivel as chair of the State Water Resources Control Board. Esquivel fielded questions from senators covering a range of contentious issues the administration has been grappling with across two presidential administration and an extreme drought.
With California in drought conditions amid the third-driest precipitation totals in state history, Valley lawmakers want Gov. Gavin Newsom to take immediate action.
On Wednesday, a bipartisan group asked Newsom to declare a statewide water emergency. The governor’s office responded by saying Newsom will take action “if it becomes necessary.”
San Joaquin Valley farms and Southern California cities are facing different but equally daunting water challenges. For Valley farmers, the requirement to achieve groundwater sustainability in coming years has heightened interest in expanding water supplies to reduce the need to fallow irrigated farmland. For Southern California, falling demands since the early 2000s have reduced water stress during normal and wet years, but a warming climate makes future droughts a major concern.
La Niña is back.
It’s been a couple of years since satellites and buoys detected the mass of cold water forming along the equator. National Weather Service meteorologist Alex Tardy said when you average out the effect of La Niñas over the last few decades, they tend to indicate we’re in for less precipitation than what we’d get in an average winter.
Droughts are common in California. The drought of 2012-2016 had no less precipitation and was no longer than previous historical droughts (Figure 1), but came with record high temperatures (Figure 2) and low snowpack (Figure 3), which worsened many drought impacts. Water supplies for agriculture and urban users statewide struggled to meet water demands. Conservation and rationing, increased groundwater pumping and a diversified economy helped keep California’s economy robust in most sectors. The drought degraded environmental conditions in the Sacramento-San Joaquin Delta as the region became saltier and warmer, invasive weeds spread, and iconic fishes like salmon and Delta smelt had strong declines.