Data Centers and Coldwater Fisheries

Data centers have been in the news of late. While they are being framed as economic catalysts for communities, they have the potential to negatively impact coldwater fisheries. Minnesota Trout Unlimited (MNTU) has significant concern over the development of data centers in the state, particularly due to their potential impact on coldwater trout habitats. MNTU’s core concern is the pumping of large volumes of groundwater by data centers for cooling purposes. Groundwater springs are the lifeblood of trout streams and high-volume groundwater withdrawals can lower water tables, reduce stream flows and elevate water temperatures, which are all detrimental to trout populations that require cold, oxygen-rich waters to thrive. Excessive groundwater extraction can deplete surface waters and affect household wells, especially in communities relying solely on groundwater.

Key issues related to data centers:

1. High Water Use: Many data centers want to use large volumes of groundwater for cooling, rather than other alternatives.  In regions like Minnesota, where coldwater trout streams rely on consistent groundwater inputs, large-scale water withdrawals can reduce stream flow and raise temperatures, both of which can be harmful to trout populations.

2. Thermal Pollution: If water used for cooling is discharged back into natural systems, it may raise the temperature of nearby water bodies. Trout are extremely sensitive to water temperature, even slight increases can reduce oxygen levels and threaten their survival.

3. Groundwater Depletion: Trout streams in Minnesota often depend on groundwater-fed systems to stay cool and stable throughout the year. Large-scale water withdrawals by data centers may lower water tables, threatening these natural inputs.

4. Energy Demand and Climate Impact: Data centers are energy intensive. If their power comes from fossil fuels, they contribute to greenhouse gas emissions. Climate change can further stress coldwater habitats by warming air and water temperatures and altering precipitation patterns.

5. Siting Concerns: Poorly sited data centers may encroach on critical watersheds or protected areas. MNTU would be concerned about developments near sensitive trout streams or aquifer recharge zones.