Arizona’s groundwater levels are dropping.
The U.S. Geological Survey measured water levels at about 1,300 wells across the state, and in most cases, the water table had fallen by at least one foot per year.
Over the last 70 years, groundwater in Arizona's alluvial basins has been depleted by more than 74.5 million acre-feet, or approximately three times the maximum storage of Lake Powell, according to the agency.
It was 1980 the last time the USGS did such a comprehensive study.
"It’s critically important to continue to monitor water levels," said Fred Tillman, a research hydrologist with the USGS. "That’s something that tends to get lost in times of budget cuts. It’s very important to know."
About 20 percent of the wells actually showed rising water levels, according to the report. That includes areas near Tucson where surface water from the Central Arizona Project is spread out into large recharge basins.
Most of the declines come from agricultural use and demand from big cities, Tillman said.
