The DNR does not issue a permit for a data center as a facility, but rather for the facility's use or impacts on natural resources. The DNR’s authority is derived from Iowa Code 455B, which outlines jurisdiction for water use, air quality, wastewater construction, wastewater discharge and floodplain management.
- Zoning vs. Regulation: The DNR does not propose or enforce zoning restrictions. Land use, local ordinances, and zoning approvals are the exclusive domain of local city or county governments.
- Compliance Enforcement: The DNR maintains the authority to conduct inspections to ensure ongoing adherence to permit conditions.
- Required permits from DNR may include the following: Water Use, Air Quality, Stormwater, Wastewater Construction, Wastewater Discharge (NPDES), Floodplain.
Water Use
In Iowa, the authority for water rights is with the DNR on behalf of the state. The Water Use Program issues water withdrawal permits to entities withdrawing 25,000 gallons or more of water in a 24-hour period from any surface or groundwater sources.
- Criteria for Approval: Applications are reviewed against three primary standards:
- Beneficial Use: Ensuring that the water is applied to a useful purpose without being wasted.
- Well Interference Protection: Ensuring withdrawals do not drop water levels in neighboring residential, municipal, or agricultural wells below functional limits.
- Resource Sustainability: Confirming that the water source can sustain the withdrawal rate long-term, and that no adverse changes to the water course will result from the proposed use. Approved permits include provisions for both routine conservation practices and emergency conservation measures.
- Timeline and Transparency: Review typically takes 90 days after a complete application is received. Water Use Draft Permits are posted on Iowa DNR’s web site, for public comment. There is a 20-day public notice period; a public hearing may be requested. Comments may be submitted to [email protected] .
- Permit Duration: Permits are generally valid for 10 years, though permits for the Jordan Aquifer are limited to 5 years.
Connection to an Existing Water Supply
The majority of data centers in Iowa do not supply their own water. They purchase water from municipal utilities. The utility holds the DNR permit, and the data center negotiates rates and infrastructure costs directly with the city. Because municipal systems do not report individual user data to the DNR, exact water use for data centers is not directly reported to the DNR.
Stormwater
Stormwater (General Permit #2): Required for any construction activity disturbing one or more acres. Developers must maintain a Stormwater Pollution Prevention Plan (SWPPP) until the soil is stabilized and all land-disturbing activities at the site have been completed, and that a perennial vegetative cover has been established or equivalent stabilization measures have been completed.
Wastewater
Discharge: Cooling "blowdown" water contains concentrated minerals and chemicals. If discharged into surface water, a federal/state National Pollutant Discharge Elimination System (NPDES) permit is required.
Pretreatment: If discharging into city sewers, facilities must comply with local municipal pretreatment ordinances.
Floodplain
Floodplain Permit: Required if a data center or related development is located in a 100-year floodplain, which meets the drainage area requirements in Iowa law. Developers generally avoid these areas during site selection to mitigate operational impacts. For developers that do request a floodplain development permit, Iowa law requires permitted structures to be elevated or floodproofed and requires that permitted structures and fill be set back far enough to not restrict the flow of the stream or river.
Air Quality
Emergency Generators: Data centers require substantial backup power and rely on diesel generators. A separate construction permit or modification is typically required for nearly every individual generator installed.
Environmental Review
For projects taking place on private property, a formal environmental review is not required by Iowa law.
However, project developers may voluntarily request that the DNR conduct an environmental review to evaluate proposed construction for potential environmental impacts. This review cross-references project boundaries against state database records, such as the Iowa Natural Areas Inventory, to identify potential conflicts with state- or federally-listed threatened and endangered species, sensitive habitats, rare natural communities, and protected state lands or waters. Developers may use this information to modify project plans to lessen impacts to sensitive areas and to avoid violating laws such as those protecting threatened and endangered species.