Tuesday, March 31, 2015

What does it mean to "run out"?

Re: the California drought, from the Los Angeles Times:

"It is the economics of having to go deeper and deeper for groundwater that will ultimately force growers to retire land. It's not that the Central Valley's thick aquifer will run dry. Scientists estimate that it holds roughly 800 million acre-feet of water that seeped deep into the valley's sands and clays over millenniums from streams and rivers swollen with runoff from the neighboring Sierra Nevada and coastal ranges.

Farmers will instead run out of water they can afford to pump. As the groundwater table drops ever lower, wells become prohibitively expensive to drill, water quality deteriorates and it takes more energy, and thus money, to pull supplies from depths of 2,000 feet or more."

"To save our valley, we have to police ourselves," Pitigliano said, acknowledging that it won't be easy.