Data Center Concerns and Recommended Ordinance Standards

A Starting Point for a Dubuque County Data Center Ordinance

Prepared by the Data Center Accountability for the Citizens of Dubuque Group

The concerns below reflect issues documented in communities across the United States and worldwide where large-scale data centers have been built, together with items raised by Dubuque County residents. Each item represents a topic the Zoning Commission may wish to address through specific, enforceable ordinance standards before applications are considered.

1. Farmland, Siting, and Land Use

• Permanent loss of high-quality agricultural land; once prime farmland is converted to industrial use, it does not return to production.
• Siting on high-productivity soils (e.g., high CSR2-rated ground in Iowa); lower-quality or already-industrial sites should be used where available.
• Incompatibility of industrial-scale buildings with agricultural and rural residential zoning districts.
• Fragmentation of contiguous farm operations and interference with field access, drainage tile, and farm equipment movement.
• Pressure for speculative rezoning of surrounding parcels once a first facility is approved.
• Need for a density clause limiting the number and concentration of data center campuses in the county so that approvals do not cluster into a de facto industrial corridor.
• Setback from municipal boundaries: Allamakee County, Iowa prohibits data centers within two miles of city limits — a model worth considering, which also reduces annexation pressure.
• Size definitions and thresholds should be based on total campus acreage, not building square footage; rezoning requests are presented and approved at the campus level, and building-size definitions invite phased end-runs around thresholds.

2. Water Use and Water Quality

• Very high water consumption for evaporative cooling — some facilities use millions of gallons per day, competing with municipal, agricultural, and residential wells.
• Drawdown of local aquifers and impacts on private well owners, with limited recourse for affected neighbors.
• Required pre-construction well studies of surrounding properties and continuous water quality and water level monitoring for the life of the facility, at the operator's expense.
• Where closed-loop cooling is claimed, the application must include a complete closed-loop system plan: maintenance schedule, leak detection and response, flushing intervals and procedures, contaminant monitoring and separation, and refilling procedures and volumes.
• Discharge of heated water, blowdown water, and water-treatment chemicals into streams or sewer systems.
• Stormwater runoff from large impervious rooftops and parking areas, increasing flooding and erosion downstream.
• Lack of disclosure: in many communities, water use figures were kept confidential until after approval.

3. Karst Geology, Sinkholes, and Groundwater Protection

Much of Dubuque County lies within the Driftless Area, where shallow, fractured limestone and dolomite bedrock creates karst conditions: sinkholes, losing streams, springs, and rapid pathways from the surface