By Melissa St. Aude | Casa Grande Dispatch
By 2109, Pinal County residents could be searching for water as far as 1,100 feet below the ground, if groundwater pumping continues at current levels and the aquifer is not replenished.
That was the scenario presented Tuesday to the Pinal Local Water Group in a report of assured water supply presented by Jeff Tannler, statewide active management area director for the Arizona Department of Water Resources.
“It looks bad, but it’s not worst-case scenario,” Tannler said.
Future development and a growing population could put an even greater strain on already overburdened groundwater supplies, he said.
Tannler’s presentation used groundwater models to look at historic water depth levels. The models were then adjusted to modern-day levels and 100 years into the future.
In 1900, much of the groundwater in Pinal County could be found within 50 feet of the surface, according to the report. After decades of pumping hundreds of acre feet of water from deep underground, by 1977 water levels had dropped to 300 to 400 feet below the surface.
Groundwater levels have started to recover in recent years, due in part to an influx of Central Arizona Project water from the Colorado River and conservation efforts. But CAP water is expected to be reduced in future years and a replacement source has not been identified.
If pumping levels continue and groundwater is not replenshed, only 20 years into the future, much of the water in Pinal County could be more than 500 feet below the surface. By 2059, in some areas around Maricopa, water levels will lie more than 1,000 feet underground. Water in Eloy and Casa Grande could be more than 600 feet below ground, according to the report.
“As time goes on, wells start drying up and the water levels drop below the well,” Tannler said.
Pulling so much water from the ground could lead to several more feet of land subsidence in various parts of the county, according to the report.
