Rain or shine, good water management is necessary to improve a city’s sustainability. 

UT researchers have recently found that when cities store surface water in underground aquifers they increase the groundwater supply, even in depleted areas. At a time when states such as California have had to import water and impose restrictions on usage, understanding how to use water efficiently is very important. 

According to the United States Geological Survey, groundwater is the source of about 33 percent of the nation’s water. For people in rural populations, that number goes up to 90 percent. Managing groundwater resources properly is important for sustainability, according to Bridget Scanlon, lead author of this study from UT’s Bureau of Economic Geology.

“Fixing the disconnect between regions of extreme drought and areas with intense flooding can be difficult,” Scanlon said.

The process of storing surface water in underground aquifers, a technique called managed aquifer recharge, benefits areas that struggle with drought, according to Scanlon.

When city workers do not intentionally store water, it can run off into water bodies, such as reservoirs. For example, Texas lost a lot of the water from last year’s unusually wet spring. 

“A lot of that excess surface water discharged into the Gulf of Mexico,” Scanlon said. “If we could have captured it during that wet period and stored it in aquifers, then we could have much more water during our later dry periods.” 

On top of that, when cities store surface water in aquifers, they minimize water lost due to evaporation since the water is underground.

The researchers also discussed conjunctive use, or using surface water during wet periods and groundwater during dry periods.

“Conjunctive use is important because you stop pumping the groundwater so it can have time to recover,” Scanlon said.

Researchers can already see the results of these water management techniques. These water storage techniques helped raise groundwater levels by 300 feet in a managed aquifer in California.

“It’s like a bank,” Scanlon explained. “You can deposit water during wet periods and make a withdrawal when there is a period of extreme drought.” 

She said that achieving this kind of water security through additional aquifer recharge projects is important.

In addition to the environmental impact, the financial impact of improper water management is significant. California is currently investing $2.7 billion to expand water storage, which will help it prepare drought-prone regions for extreme weather conditions.

“Managing water resources can be very challenging, but the applicability [of this research] is expansive,” Scanlon said.