Reaching the Limits of Groundwater
For over a century, Rochester has relied on the Jordan aquifer for its water. This massive underground formation stretches across seven states and provides the city with a steady supply. Municipal utility managers have kept pace with recent population growth by drilling new wells. Today, about 30 wells reach down into the aquifer between 400 and 1,000 feet below the surface. That approach is now hitting a wall.
The Minnesota Department of Natural Resources notified Rochester Public Utilities in 2024 that it cannot permit additional wells within city limits. The agency concluded that further withdrawals could harm nearby streams and wetlands. These surface waters provide critical habitat for rare species and are popular spots for local anglers. City officials have started a long-term study to determine how to meet future water needs without damaging the local environment.
Tim McCollough, general manager for the utility, described the state’s decision as expected rather than shocking. He notes the city must plan for a 40-year horizon of population growth. The core question for the utility involves the impact of continuing to draw from the Jordan aquifer compared to other potential sources.
Challenging the Status Quo
Rochester residents currently use roughly 4.8 billion gallons of water each year. Utility projections suggest this demand will nearly double by 2065. However, the state has capped the city’s annual draw from the Jordan aquifer at 5.7 billion gallons. At current growth rates, the city expects to hit that ceiling within five years. This situation places Rochester in a position similar to other Minnesota suburbs like White Bear Lake and Woodbury, where overpumping has caused significant controversy and resource management challenges.
Most large municipalities typically use surface water from lakes or rivers. Surface water recharges much faster than the underground aquifers Rochester prefers. The Twin Cities region transitioned to the Mississippi River as it expanded, yet Rochester officials remain hesitant to follow that path. Some city leaders take pride in the high quality of their tap water and the lack of a major, expensive treatment center. Council member Patrick Keane pointed out that many residents view their current system as a point of local identity.
The utility has examined using manmade reservoirs in the Zumbro River as a backup. Keane remains concerned about whether these local sources could provide sufficient volume to support the city. The Mississippi River is another potential option, but it sits 40 miles away, presenting a difficult logistical and financial hurdle. Building a new treatment facility to handle surface water would cost millions of dollars and introduce new operational burdens that the city has not yet had to manage.
The Cost of Future Security
Utility staff remain interested in maintaining a groundwater-only system to avoid the costs of a new surface water treatment plant. They are exploring the possibility of drawing from deeper, non-renewable aquifers like the Wonewoc and Mt. Simon formations. Geologists warn that this strategy is effectively mining for fossil water. The water in the Mt. Simon aquifer is estimated to be 60,000 years old. Once it is gone, it cannot be replaced within a human timeframe.
Local farmers such as John Meyer are vocal critics of drilling deeper. Meyer uses cover crops on his land to improve soil health and increase water filtration. He argues that deeper wells merely delay the consequences of depletion and surface contamination. He believes the city should focus on conservation and protecting the resource from the top down. Currently, the city’s water conservation program relies entirely on voluntary participation from residents.
Rochester has not yet enacted the mandatory watering restrictions seen in other parts of the state during recent drought cycles. City officials believe they have time to evaluate their options before the situation reaches a crisis point. The utility expects to receive the results of its water study in October. This report will guide the decision on whether to pursue surface water, increase deep-aquifer mining, or adopt a hybrid model. The city aims to finalize its long-term water strategy by early 2027.