PHOENIX — Groundwater pumping in Arizona has drastically affected the water supply. It's also leading to a permanent change in the landscape, causing the land itself to sink.
This is known as subsidence, according to Dr. Ryan Smith of Colorado State University's Department of Civil and Environmental Engineering, and it's been a problem in Arizona's agricultural centers where lots of water is used to irrigate crops and feed livestock.
Dr. Smith and his colleagues developed a new model that maps out these areas globally using observed data and machine learning.
They've learned that groundwater pumping is part of the reason for the sinking.
"The study essentially found that areas that have a lot of clay in the subsurface, that clay is really weak, and it compacts really easily," Dr. Smith stated.
Places in southeastern Arizona, like Willcox, have some of the worst subsidence in the state, sinking close to ten feet since the late 1960s.
The mapping done by CSU highlighted the hotspots in Arizona and around the world.
Arizona State University's Kyl Center for Water Policy also showed Gila Bend as an area dealing with subsidence, which can lead to infrastructure damage and has in the past, which has impacted home foundations, canals, railways, and roads.
For now, concerns about subsidence remain outside of Arizona's metropolitan areas like Phoenix and Tucson, but with continued water shortages on the Colorado River and a lack of groundwater regulation in rural Arizona, the issue will undoubtedly continue in other parts of our state.
"We don't just have to stop depleting our aquifers; we have to start replenishing our aquifers," Dr. Smith said. "Otherwise, subsidence will continue for potentially decades in some areas."
