Scientists have known California is sinking for years, but new data from NASA show the state is subsiding even faster than previously thought due to relentless pumping of groundwater – largely for agricultural purposes. According to LiveScience, NASA officials say some parts of the state are dropping at a rate of more than 2 inches per month due to groundwater extraction, and if the trend continues, the land could permanently lose its capacity for storing water underground.
“Because of increased pumping, groundwater levels are reaching record lows – up to 100 feet lower than previous records, Director of California’s Department of Water Resources, Mark Cowin said in a statement. “As extensive groundwater pumping continues, the land is sinking more rapidly, and this puts nearby infrastructure at greater risk of costly damage.”
According to the U.S. Geological Survey and LiveScience, some areas of California are already as much as a few dozen feet lower than they were in 1925. But in the midst of the state’s worst drought in recorded history, where 97 percent of California is currently facing moderate to extreme drought conditions, the unprecedented pumping of groundwater is exacerbating the problem.
The epicenters of sinking in the state include: the Tulare Basin around Fresno, which sank a whopping 13 inches in only eight months; the Sacramento Valley, which is sinking about half an inch each month; and the California Aqueduct that brings water from the Sierra Nevada mountains to Southern California, which has sunk 12.5 inches in the past four months.
It’s no surprise that some of these areas are important for agricultural production. Farmers have been forced to suck out more and more groundwater to keep their crops growing, as surface water supplies have dwindled during the drought.
The sinking of land can cause major problems with infrastructure, such as cracking of bridges and highways. And according to Mark Corwin, pumping out all that groundwater is akin to spending everything in your savings account. And once aquifers are drained, the underground channel collapses, which means that when, and if, water returns, it has nowhere to be stored underground.
“Groundwater acts as a savings account to provide supplies during drought, but the NASA report shows the consequences of excessive withdrawals as we head into the fifth year of historic drought,” he says. “We will work together with counties, local water districts, and affected communities to identify ways to slow the rate of subsidence and protect vital infrastructure such as canals, pumping stations, bridges and wells.”