A new, widely covered research paper from Nature describes the long-term catastrophic collapse of underground water systems in the US and worldwide. The primary contributor is irrigation. This presents another problem. Irrigated land feeds hundreds of millions of people worldwide.
“Irrigation is estimated to account for 70% of global groundwater withdrawals,” the authors wrote in a paper titled “Rapid Groundwater Decline and Some Cases of Recovery in Aquifers Globally/.”
It is worth noting in America, the USDA reports, “According to the 2017 Census of Agriculture, farms with some form of irrigation accounted for more than 54 percent of the total value of U.S. crop sales, while irrigated land accounted for less than 20 percent of harvested cropland” There are no similarly accurate worldwide totals.
The Scope of the Study
The study examined groundwater-level activity in 170,000 monitoring wells and 1,693 aquifer systems. The countries analyzed have about 75% of global groundwater withdrawals.
As expected, the huge water system that includes the Colorado River, the western mountains, and the states of California, Nevada, and Arizona are singled out, as are the vast California farms that use a huge percent of the water supply to those areas. This problem has caused friction between these farmers and municipalities in the region.
The paper’s authors voiced optimism about a small number of areas where the groundwater problem has been reversed to a relentlessly negative trend in the huge majority of cases.