Uncharted Waters

Data center rush hour requires monitoring speed limits

Photo by Benjamin Chambon on Unsplash

If there’s not a yellow caution light flashing at the city limits of Palo, Iowa, population 1,627, there should be. Earlier this week, when 150 residents attended the City Council’s first reading and public forum for a zoning ordinance governing a proposed 545-acre Google Data Center, many proposed more regulations on water use and traffic, asking: “What’s the rush?”

Linn County wanted to be proactive when it wrote its ordinance in response to Google’s original plan to locate in an unincorporated area of the county. However the city of Palo isn’t requiring a study to determine if the estimated 14 million gallons per day pulled from the Cedar River would be sustainable. Instead, the original site would be annexed into its city limits and Palo would apply for a DNR-issued permit to assure an adequate water supply.

Selling large amounts of water is a lucrative source of revenue for city governments, and new industry often is a welcomed expansion to the property tax base. The revenue-generating spigot of new industry can cloud a local government’s vision of the future impact.

So it’s rush hour in many Iowa communities today. Sprawling data centers are the latest in a series of industries ushered in as economic development. They’re raising critical questions regarding:

(1) utility rates

(2) water competition

(3) tax policy

(4 local land use decisions

“Iowa needs a groundwater plan,” Keith Schilling, State of Iowa geologist and director of the Iowa Geological Survey told the Soil Management and Land Valuation Conference at Iowa State University last week. “Data centers use a lot of water. Most use municipal water supplies to cool their servers, and they’re not required by Iowa law to report their water or energy consumption.”

He added, “I’ve raised the issue of mapping groundwater supplies to the Legislature over the past several years. We need to monitor our aquifers to know what’s been pumped out, how the system is recharging, and if its current use is sustainable. From my perspective, it makes sense to assess water resources upfront when a new industry comes in, providing communities with solid data for decision-making.”

Water under pressure

Based on Iowa DNR records, Iowa currently has 101 data centers in operation; just one Google data center in Iowa used one billion gallons of water in 2024.

Iowa isn’t alone. Nationwide, water use is expected to triple by 2030, much of it driven by the explosive expansion of artificial intelligence and cloud computing. In 2022, there were 2,701 data centers in the U.S. By March 2024, the number had ballooned to 5,381.

This week Utah legislators demanded that the 40,000-acre Stratos AI data center project in Box Elder County north of the Great Salt Lake backed by Shark Tank investor Kevin O’Leary be pared down to about 10,000 acres. Other environmental and agricultural protections and power structure concerns also were raised.

Underground water storehouses

Centuries ago a series of glaciers inched across prehistoric Iowa. As they melted, they created rivers and recharged subterranean bedrock strata which became huge storehouses for water called aquifers. But, as Schilling points out, groundwater in aquifers isn’t equally distributed across Iowa. Its porosity also varies, from water trickling only a few inches per year to water flow measured in feet per minute.

Furthermore, there are different types of aquifers, with ancient rock layers of dolomite, sandstone, and shale. They range from 5,200 feet deep in southwest Iowa to the ground surface in northeast Iowa.

The two types of bedrock aquifers are:

· Unconfined: shallow, open to the atmosphere, recharged by infiltration/precipitation. Subject to fluctuating levels.

· Confined: Not recharged by rainfall. Requires time to filter through artesian pressure, and recharge. It’s old water, readily impacted by drought

· Alluvial aquifers are a shallow type of unconfined aquifer; they line rivers, formed in sand and gravel, and require rainfall to recharge.

Photo by NOAA on Unsplash

One of Iowa’s primary bedrock aquifers is the Jordan Aquifer (Cambrian-Ordovician). It’s the deepest in the state, ranging from 1,500 to 2,000 ft. It likely was formed 1/2 billion years ago, and the Iowa Geological Survey based at the University of Iowa has determined some of its water dates back hundreds of thousands of years. It underlies across almost the entire state.

Iowa has three other smaller, primary bedrock aquifers:

· Dakota Aquifer, beginning in northwest Iowa, with a slender finger extending into southwest Iowa; not readily recharged. Its levels have been declining.

· Silurian/Devonian covers almost the same areas as the Jordan, with the exception of far northwest and is commonly used in eastern and northeast Iowa; recharged readily but vulnerable to contaminants

· Mississippian, stretching across the southern two tiers of Iowa counties and extending as far north as Clear Lake.

More transparency needed

New users of water may compete with municipal water systems relying on the same aquifer. Cities are required to annually report water capacity to the DNR, including static and pumping rates.

A bill introduced by Cedar Rapids House member Cindy Golding (R) would have required data centers to file quarterly reports with the Iowa DNR. It passed out of committee in 2026, but didn’t advance.

Photo by Igor Omilaev on Unsplash

Microsoft, with its five centers in West Des Moines, draws from the Des Moines Water Works, which is sourced from the Raccoon River and the Jordan aquifer. Meta in Altoona draws from municipal water, supplied by the Jordan aquifer. To meet future needs, it plans a new water plant, and a taxpayer-funded deep well. In Davenport, the proposed Meta data center would be supplied by the Mississippi River; Google, in Council Bluffs, sources its water from the Missouri River aquifer; Apple near Waukee draws from surface waters and the Des Moines and Raccoon alluvial aquifers.

Cedar Rapids and Iowa City obtain their municipal water from alluvial aquifer wells.

Schilling says Iowa lags its neighboring states in the critical issue of mapping aquifers. Only about 50 Iowa wells have been mapped to provide a benchmark of alluvial aquifer well levels, and fluctuations. Here’s how other states stack up in the number of monitored wells:

· Wisconsin, 152

· Missouri, 173

· Illinois 307

· Minnesota 1,500

· Nebraska, 5,269

But Schilling has been working with the Legislature, and it’s approved a series of three, one-year temporary appropriations to develop models to budget water resources, and provide maps of:

· the volume of groundwater available for various uses

· the current and predicted allocations of groundwater supporting these uses

· the recharge rate for the aquifers

The first report will be issued soon; it will map alluvial aquifer wells from Marshalltown to Iowa City, creating a water budget for the Iowa River flood plain at a cost of $250,000. The next one will focus on the Ocheyedon alluvial aquifer) near Spencer, followed by the Boyer River aquifer in western Iowa, and finally the West Nishnabotna in southwestern Iowa.

“We’ll also assess why water levels in the Dakota aquifer have declined 10 or more feet,” Schilling says. “Without aquifer maps, if you have a problem, you don’t have any background to make regional assessments.”

He adds, “Bedrock aquifers need mapping, too. It’s more expensive. I’ve asked the Legislature to build a bedrock aquifer monitoring network, but nothing has happened yet.”

Water-hungry industries

Data centers aren’t the only uses of Iowa’s water awarded by government in the name of economic development:

· Ethanol plants are a big user, requiring three to six gallons of water to produce one gallon of ethanol.

· Carbon Summit Solutions pipeline’s water permit would allow withdrawal of up to 56 million gallons of water annually from the Devonian aquifer near the Lawler ethanol plant.

· One sand mining company in Clayton County relies heavily on the Jordan aquifer. Requests have been made to the DNR to quadruple its water withdrawal limit. It also has proposed shipping water out West

· Agriculture: irrigation is increasing across the state. the number of irrigated acres in Iowa has catapulted 55%: from 773,000 acres in 2012 to about 1.2 million acres in 2022.

What happens in times of drought? Who will be first in line for Iowa’s water?

Schilling warns about well interference in confined aquifers, where pumping creates intersecting cones, drawing down water levels. “Well interference will happen more and more,” he says.

Data centers have promised new water-conserving technologies, including advanced close-loop cooling systems, direct to chip liquid cooling, and the use of reclaimed wastewater.

Schilling doesn’t assign blame to data centers or any other water-intensive industries. “Water supply usually isn’t the first question asked by a new industry,” he told me. “Sometimes it’s the last question. Cities need to do more planning, evaluating, and monitoring to know if they have adequate water supplies before soliciting new industries.”

Iowa’s uncharted waters

Most of the stories I’ve written over the years concerning water have focused on threats to the Ogallala Aquifer in the West, or the impact of widespread droughts. Like many Iowans, I always assumed Iowa was a water-rich state, thanks to abundant rainfall and ample underground resources. It may be true, but our waters are uncharted.

Growing up in Iowa agriculture, I was ingrained with the core belief that water and land are precious finite resources to be used to benefit humankind. The concept of water as one of the state’s economic development tools has been a hard lesson to learn.

Over the years I’ve heard most of the siren songs of new industry, promising more jobs, and long-term economic growth. Unfortunately, I’ve also observed how communities impacted the most by these economic opportunities seldom benefit from the wealth created by corporations focused on outsourcing their costs of doing business.

I’ve had a front-row seat for other Iowa rush hour traffic: hog confinements, farm consolidations, and oil and carbon pipelines. I’m keeping an eye on the impact of solar and wind farms on land values, and the lack of a level playing field for young farmers attempting to gain a foothold. In Iowa, we’re seeing the millions annually awarded in credits, exemptions, tax abatements, and incentives – all sucking dollars away from local schools and governments.

Today’s latest rush hour features data centers, and the pace is accelerating. Palo isn’t alone. A dozen miles away, another Linn County town, Fairfax, population 2,851, has two data centers under construction just to its north, in addition to the third proposed near Palo.

Traffic is the biggest complaint so far, the Fairfax mayor told Palo residents. It’s become a safety issue, and residents can’t get out of their own driveways. The council is considering new signage and speed enforcement.

The same may be true regarding the rapid pace of new data centers in Iowa. The speed is breathtaking. It’s time to pump the brakes.

Photo by Gabriel Paulus on Unsplash

I’m proud to be a member of the Iowa Writers’ Collaborative. Please check out our work here. Please consider being a paid subscriber. Thank you for your support!