Rochester Public Utilities is nearing a decision point in a broad study of water resources that will shape how the city meets future demand, RPU officials said. The analysis, which covers roughly 1,500 square miles of southeastern Minnesota, will inform whether the city can continue to rely on the Jordan aquifer, drill deeper, or look to surface-water sources such as the Zumbro or Mississippi Rivers.
Background and regulatory context
The study, initiated about two years ago, was required by the Minnesota Department of Natural Resources as a condition for permission to drill additional wells into the Jordan aquifer or other sources. RPU General Manager Tim McCullough discussed the work on the RPU Unplugged segment of Rochester Today on News-Talk 1340 KROC-AM and 96.9 FM.
"the study began about two years ago"
The Jordan aquifer currently supplies Rochester’s drinking water. Located about 450 feet underground, it is part of one of the largest groundwater systems in Minnesota and has for years been the exclusive source for the community’s water.
Modeling impacts and the options under study
RPU is using sophisticated computer modeling to assess whether additional pumping from the Jordan aquifer would affect surface waters — including rivers, streams and wetlands — within the study area. The models cover groundwater and surface-water interaction across the 1,500-square-mile region surrounding Rochester.
- Continue current use — Maintain reliance on the Jordan aquifer, subject to modeling showing limited impact on surface waters and any required treatment upgrades.
- Deeper drilling — Investigate tapping into deeper aquifers, pending technical feasibility and regulatory review.
- Surface-water sources — Evaluate pulling water from the Zumbro or Mississippi Rivers as an alternative or supplement to groundwater.
McCullough said the study is approaching the stage when enough data will be available to evaluate the potential options and identify treatment needs and costs. He expects RPU to present the findings to both the RPU Board and the Rochester City Council this fall.
Local consequences and next steps
For residents and local planners, the study’s conclusions will have direct implications for long-term water reliability, infrastructure investment and possible treatment upgrades. Any new wells or surface-water intakes would require regulatory review, and the DNR’s involvement means that environmental impacts are central to the decision-making process.
| Option | Primary source | Key consideration |
|---|---|---|
| Maintain Jordan aquifer | Jordan aquifer (~450 ft) | Modeling must show minimal effect on surface waters; potential treatment costs |
| Drill deeper | Deeper aquifer | Technical feasibility and regulatory approval |
| Surface-water sourcing | Zumbro or Mississippi Rivers | Infrastructure to withdraw and treat river water; environmental review |
RPU’s focus on modeling across a broad geographic area recognizes the interconnectedness of groundwater and surface-water systems. The DNR required the study because of the potential for groundwater withdrawals to reduce flows or otherwise affect rivers, streams and wetlands, a consideration that will shape whether additional pumping from the Jordan aquifer is permitted.
Rochester operates what McCullough described as one of the state’s largest groundwater systems. The utility’s next public steps will be the formal presentation of study findings this fall and subsequent deliberations by the RPU Board and City Council, which may involve discussions about project costs, treatment needs and timelines.
Until the study’s final results are released, city officials and residents can expect continued analysis and public updates from RPU as the utility works through regulatory and technical questions tied to Rochester’s long-term water supply.
