After weeks almost constant rain and floodCalifornia is finally drying up – but let’s hope not too dry since the state needs as much rain as it might get out of its historic drought. This is California’s craziest and most contradictory one: climate change is causing each dry spells and downpours to change into more intense, ping-pong the state’s water systems between critical deficiencies and downpours over the canals.
The simultaneous solution to each extremes is true under the feet of Californians: aquifers, which consist of underground layers of porous rock or sediment reminiscent of gravel and sand, which fill with rainwater seeping through the soil above. This water can come to the surface naturally to form a spring, or you may dig a well to make use of it. These days, powerful pumps pump water from a whole bunch of feet deep.
California’s Central Valley is stuffed with such aquifers, able to holding about 46 trillion gallons of water, 3 times the state’s entire reservoir. But this a part of the state has long overexploited them; 20,000 square mile valley, agricultural, growing 40 percent national fruits, nuts and other table dishes. (Agriculture generally constitutes 80 percent total water consumption in California). tens of feet.
This has led to a dramatic imbalance, says UC Davis hydrogeologist Graham Fogg, who studies California’s aquifers. “Civilizations all over the world were really experts at practically uncontrollably draining groundwater, but we were terrible at getting water back into the bottom,” he says. “It’s a bit like mismanagement of a checking account where you are really good at withdrawing funds but ignoring deposits for many years.”
To make matters worse, California’s mounting water debts are already due. The state’s outdoor reservoir system is designed to gather water throughout the rainy season after which distribute it through the dry summer in a Mediterranean style. But during drought, the degrees of those reservoirs drop to critical levels, as before the last atmospheric rivers hit in late December and early January. Moreover, higher and better temperatures cause the evaporation of more of this water.
But Fogg and his colleagues have a plan to balance the state’s water budget: using giant sensors dangling from helicopters and towed behind all-terrain vehicles to strategically goal specific areas to recharge the aquifer. They just need to search out places with the proper geology.
Fogg and his the team searches for ancient features called paleo valleys.
Interestingly, the underground waterways of the Central Valley were created by flowing water aboveground. The Sierra Nevada, the mountain range that borders the eastern end of the valley, was once covered with glaciers. When the ice melted, the resulting rivers cut through the channels, spitting out all kinds of sediments that deposited in layers. These are paleo valleys which are as much as a mile wide and 100 feet deep. They’re very, excellent at channeling water underground.
