The Minnesota Supreme Court ruled Wednesday that a creek in Renville County should be afforded more environmental protection than a ditch, but it stopped short of applying the decision to waters across the state.

While the decision settles the question of Limbo Creek, it's unclear whether it will affect other conflicts around the state involving drainage projects that preserve farmlands but increase the volume of water and pollutants flowing downstream. The question of whether streams are "public waters" or simply ditches determines how much they can be altered, and how closely projects are reviewed.

The case concerning the upper reach of Limbo Creek was launched in 2020, after Renville County approved a dredging project without environmental review.

The Department of Natural Resources argued that the creek was in fact a public water, even though it wasn't included on the inventory of protected streams and lakes. Then the Minnesota Center for Environmental Advocacy sued, saying the review should have been completed.

"We're happy with the result because we accomplished here in Renville County what we wanted," said Kevin Reuther, the chief legal officer at MCEA. "We're hoping to work with the county going forward. Maybe this can be a great example of how to do a drainage project without a lot of downstream impacts."

Gerald Von Korff, an attorney representing the Renville County Board, said the decision sows confusion on whether streams are public or not by not relying on the inventory DNR already has in place.

"Obviously, we are disappointed with the result in the Supreme Court," Von Korff wrote in an email. "The issue of whether the public waters inventory can be relied upon by landowners, by the public and by county and state regulators is extremely important, and unfortunately the Court has not fully resolved that issue today."

A DNR representative did not immediately respond to a request for comment.

The court's opinion, authored by Justice G. Barry Anderson, affirmed a Court of Appeals decision that said the creek should be considered a public water, based on the definition in state statute and its inclusion on a map of these protected rivers and streams.

But it did not extend the decision beyond this case.

"It is the duty of the Legislature to clarify the relationship between the inventory and the statutory definition of public waters," the opinion read.

Tom Kalahar, an Olivia, Minn., City Council member and former technician for the Renville County Soil and Water Conservation District, said he hoped the decision would start to turn the tide on cropland drainage projects that don't consider what happens downstream.

"We simply want the agricultural drainage authorities to follow the existing rules, which they are not real keen on doing all the time," Kalahar said.

Farmland drainage can help preserve crops and fields, but at a cost of increased pollution from eroded soil, nitrogen and other substances.

In this case, Von Korff said, farmers around the creek sought the drainage project because their fields were being flooded. He argued that by going beyond the DNR's inventory of protected waters, the court has created uncertainty around the waters that are on the list now.

"Local governments will now be under pressure from development interests to challenge the public waters designations, on the grounds that the resource shouldn't have been designated," he wrote.

Reuther, however, said that it's probably more likely that waterways that should be protected are being left off the list, rather than the other way around.

"We're not too concerned about the hypothetical [Von Korff] has proposed," he said.