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Monday, March 16

California has one year of reservoir water left

The following passages are from a March 12 editorial in the Los Angeles Times that has been widely quoted in other press. The author is Jay Famiglietti, who's been quoted many times in the past few years in connection with the findings of NASA's GRACE satellite system; he's the "senior water scientist at the NASA Jet Propulsion Laboratory/Caltech and a professor of Earth system science at UC Irvine":
[...]
NASA data reveal that total water storage in California has been in steady decline since at least 2002, when satellite-based monitoring began, although groundwater depletion has been going on since the early 20th century.
Right now the state has only about one year of water supply left in its reservoirs, and our strategic backup supply, groundwater, is rapidly disappearing. California has no contingency plan for a persistent drought like this one (let alone a 20-plus-year mega-drought), except, apparently, staying in emergency mode and praying for rain.
 In short, we have no paddle to navigate this crisis.[...]
Data from NASA satellites show that the total amount of water stored in the Sacramento and San Joaquin river basins — that is, all of the snow, river and reservoir water, water in soils and groundwater combined — was 34 million acre-feet below normal in 2014. That loss is nearly 1.5 times the capacity of Lake Mead, America's largest reservoir.
Statewide, we've been dropping more than 12 million acre-feet of total water yearly since 2011. Roughly two-thirds of these losses are attributable to groundwater pumping for agricultural irrigation in the Central Valley.
Farmers have little choice but to pump more groundwater during droughts, especially when their surface water allocations have been slashed 80% to 100%. But these pumping rates are excessive and unsustainable. Wells are running dry. In some areas of the Central Valley, the land is sinking by one foot or more per year.
As difficult as it may be to face, the simple fact is that California is running out of water — and the problem started before our current drought. NASA data reveal that total water storage in California has been in steady decline since at least 2002, when satellite-based monitoring began, although groundwater depletion has been going on since the early 20th century.
Several steps need be taken right now. First, immediate mandatory water rationing should be authorized across all of the state's water sectors, from domestic and municipal through agricultural and industrial. The Metropolitan Water District of Southern California is already considering water rationing by the summer unless conditions improve. There is no need for the rest of the state to hesitate. The public is ready. A recent Field Poll showed that 94% of Californians surveyed believe that the drought is serious, and that one-third support mandatory rationing.[...]

Jay Famiglietti goes on to give three additional urgent recommendations, and which amount to saying there must be an all-out effort  now by both the public and all concerned agencies to address the state's water shortage crisis by every means possible.  
A report filed today by Amanda Holpuch for the Guardian discusses the LA Times op-ed, and emphasizes that the poll referenced by Famiglietti (and released in February) found that 61 percent of respondents still favored voluntary reductions in water use, not mandated rationing.  
The Guardian report also touches on the ongoing debates about the cause of the state's extreme drought, now in its fourth year, and its length:
Scientists are working to determine what role climate change has played in California’s drought. Earlier this month, a study by Stanford researchers showed that high temperatures increase the risk of drought conditions
Last year, two research teams said in the Bulletin of the American Meteorological Society that they could not definitively pin the drought on climate change.

A third team, which includes a Stanford researcher from the previous study, said that rare atmospheric conditions are exacerbating the drought. 
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