The Iowa Legislature allocated $250,000 this year for a study of Iowa's aquifers to make sure they don't run dry with increased use.
"As we go forward, it is going to be more critical we know what (water) we've got and what depth it is," said Rep. Norlin Mommsen, R-Dewitt, who chairs the Agriculture and Natural Resources Appropriations Committee in the Iowa Legislature.
"Especially with these data centers, which take a lot of water in cooling. Should they be going to a different depth so they don't interfere with our drinking water? There are a lot of unknowns out there."
The new money goes to the Iowa Geological Survey, based at the University of Iowa.
The funds may be used to "measure the volume of groundwater that is available for various uses, the current and predicted allocations of groundwater to support those uses, the recharge rate for the aquifers, and the development of models for budgeting this state's water resources," according to the Blufflands Protection Revolving Fund appropriation signed into law May 9 by Gov. Kim Reynolds.
Bedrock aquifers are underground rock formations that can store water. The layers of limestone, dolomite and sandstone that make up Iowa's aquifers range from 5,200 feet deep in Southwest Iowa to 800 feet in Northeast Iowa, according to Iowa's Groundwater Basics, by Jean C. Prior.
Iowa has four bedrock aquifers, each at a different depth with varying water quality:
- The Cambrian-Ordovician aquifer, commonly called the Jordan aquifer because of its Jordan sandstone formation. This aquifer underlays nearly all of the state, except for far Northwest Iowa.
- The Silurian-Devonian aquifer covers much of the same territory as the Jordan, but not far Northwest or far Northeast Iowa.
- The Mississippian aquifer stretches across the southern two tiers of counties and extends north to around Clear Lake.
- The Dakota aquifer is in Northwest Iowa with a finger that trails down into Southwest Iowa.
If you wonder why Iowa aquifer maps show a blank circle west of Fort Dodge, that's the Manson Impact Structure, where a meteorite struck Iowa 70 million years ago.
"The meteorite slammed into Iowa and obliterated the aquifers," Iowa State Geologist Keith Schilling said. "The central peak of the impact zone is actually molten basement rock and the circular area does not contain typical Iowa bedrock aquifers."
Schilling persuaded lawmakers they should use state money to study Iowa's aquifers.
"I'd gone to the Legislature a handful of times this year, especially during the drought, and talked with them about making sure we had the groundwater supplies for all of our uses," he said.
Aquifers recharge naturally through surface water filtering through layers of sediment or through managed recharge projects. But if cities, companies and homeowners are drawing up water faster than it can recharge, an aquifer can be depleted.
Iowa also has alluvial aquifers, which are shallow deposits of sand and gravel beside rivers. Some cities, including Cedar Rapids and Iowa City, get water that is treated to be drinking water from these wells.
MORE DATA CENTERS, FARM IRRIGATION
Data centers are multiplying across the United States as Big Tech companies need more servers to support computer applications, "cloud" storage and artificial intelligence.
Iowa has a handful of large data centers, some of which are being built out in phases, pulling water from aquifers and rivers to cool the servers. A proposed Google data center in Cedar Rapids could use from 200,000 gallons of water to more than 1 million gallons a day, on average.
Iowa farmers traditionally haven't needed irrigation systems, but through nearly four years of drought, more Iowa farmers are irrigating their fields rather than relying on timely rain. The number of irrigated acres in Iowa went up 55 percent from 773,000 acres in 2012 to nearly 1.2 million acres in 2022, according to the most recent Census of Agriculture.
These new water uses may start competing with municipal water systems using the same aquifer, Schilling said.
HOW WILL IOWA STUDY AQUIFERS?
In the first year, the Iowa Geological Survey will monitor and analyze data from alluvial wells in the Iowa River flood plain system between LeGrand and Iowa City. Researchers also will examine the Dakota aquifer, focusing on three or four Northwest Iowa counties where the underground water levels have lowered 10 or more feet, Schilling said.
"We're going to try to assess why those declines are occurring," he said.
The $250,000 will allow Schilling to hire a hydrologist and pay for other work with existing staff. If lawmakers keep funding the effort in future years, the Geological Survey would move to research other parts of the state.
©2024 The Gazette, Distributed by Tribune Content Agency, LLC.
