The Minnesota Supreme Court heard oral arguments on Monday in the case involving water levels on White Bear Lake.

Homeowners and others concerned about the lake sued the Minnesota Department of Natural Resources in 2012, claiming the agency mismanaged groundwater pumping and caused the lake's levels to reach historically low levels.

The lake has since recovered, and the DNR issued a study in 2018 showing groundwater pumping has a minimal impact on the lake’s levels.

But the White Bear Lake Restoration Association and the White Bear Lake Homeowners Association continue to argue that groundwater pumping permits have a cumulative impact on the lake and that the DNR failed to assess and address the issue.

A Ramsey County district judge sided with the homeowners in 2017, but the decision was overturned earlier this year by the Minnesota Court of Appeals. It said the homeowners must challenge each pumping permit individually and leave it up to the DNR to hear and decide each challenge.

The Supreme Court agreed to hear the case, but on Monday some justices seemed reluctant to weigh in on the issue. A decision is expected in a few months.

Associate Justice Margaret Chutich asked whether a ruling in favor of the homeowners could open the door for more lawsuits in other cases involving agency permits.

"What prevents just open season on every permit given in any application, whether it's mining or pipelines?” she asked.

Katie Crosby Lehmann, an attorney for the White Bear Lake Restoration Association, said the case is unique. She argued the DNR failed to look at the collective impact of its groundwater permitting decisions.

"This isn't an issue about one straw in a bathtub. You have 100 straws in a bathtub. When you look at one by one, you don't recognize the problem,” she said. “We need to have the DNR follow the law, follow the guardrails the Legislature put forth for when permits should be issued.”

The Minnesota Attorney General’s Office argued the Supreme Court should not reverse the appeals court’s decision. Assistant Attorney General Oliver Larson said there’s an administrative process the homeowners can pursue to challenge the DNR’s permitting decisions.