WATER SECURITYGroundwater Levels Are Falling Worldwide — but There Are Solutions
The world’s groundwater aquifers are taking a beating. Decades of unrestrained pumping by thirsty farms and fast-growing cities have drained these underground rock beds, which hold more than 95 percent of the planet’s drinkable water. New research shows how to protect the aquifers that hold most of the world’s fresh water.
The world’s groundwater aquifers are taking a beating. Decades of unrestrained pumping by thirsty farms and fast-growing cities have drained these underground rock beds, which hold more than 95 percent of the planet’s drinkable water, pushing countries like Iran to the brink of humanitarian disaster. Aquifer health is also suffering in the United States, where groundwater overdraft in states such as Arizona has dried out wells and caused land to sink and rupture.
But a new study published in the scientific journal Nature this week highlights the few places in the world where groundwater levels are actually recovering. Using 40 years of measurement data from 170,000 groundwater wells, a team of researchers identified a few key policies that can stop water tables from crashing — and even restore them. These policies are all difficult to execute, and each has its own economic costs, but the new data offers hope to areas like California’s Central Valley, which are struggling to slow down massive groundwater declines.
“Much of the dialogue linked to groundwater has focused on depletion, and the novelty in this work lies in our ability to profile some of these cases where groundwater levels have recovered,” said Scott Jasechko, a professor of water resources at the University of California, Santa Barbara, and the lead author of the study. “Although they are rare, these provide informative examples of ways that things might be turned around elsewhere.”
To create a map of aquifer changes around the world, the authors liaised with dozens of governments and compiled more than 1,300 different studies. The more than 40 countries from which they got data account for more than 75 percent of the world’s groundwater usage. After they created the map, Jasechko and his team zoomed in on places where water levels were rising and followed up with local governments in those areas, to see how they’d done it.
The first solution the researchers hit on is obvious: If you’re running out of groundwater, find another water source. The authors point to the success of Albuquerque, New Mexico, which relied on its aquifers to support rapid urban growth over the course of the late twentieth century. When new studies showed the aquifers had much less water than officials thought, they turned to the tributaries of the Colorado River for an alternative supply, building a treatment plant and a series of pipelines to import river water and give the aquifers a break.
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