Officials say they are worried that an area aquifer is being overused, which could affect the future water supply in Iowa City.

A $500,000 ongoing water assessment found the Jordan Aquifer, located north of Iowa City, will be depleted in 50 years if the community does not tap into alternative sources.

“We’re used to thinking we’re pretty water rich … but we see stress coming from big water-users in the area,” said State Geologist Bob Libra.

And the University of Iowa is drawing from alternative sources in order to relieve the aquifer.

“We have made a fairly ambitious action by making use of the Iowa River,” said Jerry Schnoor, a UI professor of civil and environmental engineering.

He said the Iowa River must be extensively treated before using it for drinking and hospital purposes.

But, he said, the collaboration between the university and Iowa City is essential.

“Its a town-gown effort,” he said.

Libra said the stress derives from the ethanol industry and surrounding towns pumping water from the aquifer. Archer-Daniels-Midland Co. plans to build a large plant in Cedar Rapids, Libra said.

When built, the plant will rely heavily on the Jordan Aquifer.

The 1,500-foot Jordan Aquifer’s artesian water pressure is continually decreasing. The constant use has reduced and destabilized the level of water in the aquifer, Libra said.

He said there are two “flavors of water,” on the earth, shallow water — from streams and rivers — and groundwater. He compared the water relationships to bank accounts.

“Shallow water is like a checking account — you keep paying bills as long as you are paid,” Libra said. “Deep ground water is like a retirement fund, you have it for reserve, but you eventually run out.”

The assessment measures how aquifers hold and transmit water and what direction the water flows, said hydrogeologist Mike Gannon. Though his agency provides information to businesses about how to manage water use, Libra said, ultimately towns and businesses must take the initiative to conserve water.

“You all need water, and you all need each other, so how do we want to work this out?” he said.

To help alleviate stress on the aquifer, any source pumping more than 25,000 gallons of water per day is required to apply for a water-use permit, Gannon said. So far, roughly 10 permits have been issued, he said.

Climate change is a factor in the aquifer’s supply, Libra said, which makes precise water-use predictions difficult.

“If we had a crystal ball, it would make predictions easier,” he said.

However, he said communities must remain conservative about how water is used.

“Underground water is a necessity, and in order for generations ahead of us to have water available as we do, we must take action in protecting it,” Libra said.