A decades-long feud between residents of neighboring lakes in Otter Tail County has been settled — for now.

Last week, the Minnesota Court of Appeals ruled that the waters of Hoffman Lake and West McDonald Lake will remain separate. The court refused to allow the state Department of Natural Resources (DNR) to cut a channel allowing excess water from Hoffman Lake to flow into its neighbor, also known as West Mac.

In its decision, the court faulted the DNR for not researching the issue more thoroughly, saying its decision to create an overflow channel "is unsupported by substantial evidence in the record and is arbitrary and capricious."

The DNR has 30 days to appeal the case to the state Supreme Court. Sherry Enzler, the agency's general counsel, said the department hasn't decided whether to appeal.

"We're mulling it over, weighing our options," she said. "We haven't really had a discussion."

The two lakes are separated by a slender bar, only 2 feet wide at its narrowest point. Neighbors have battled over the bar for at least 40 years, with some trying to create a channel between the two lakes, while others work to keep them separate.

In the early 1970s, someone — nobody is quite sure who — used dynamite to blow open a channel through the bar. West Mac residents later closed it up and have been vigilant about keeping the lake waters from mixing ever since.

Still, a low-level guerrilla war has continued over the years, with mysterious nighttime visits from "rock fairies" who remove riprap from the bar while others quietly put it back.

The DNR posted a sign warning against tampering with the bar, and West Mac residents installed a camouflaged spy camera in a tree to try to catch the "fairies" at work.

It's all about water quality

At the root of the feud is water quality. West Mac residents contend that their lake water is cleaner than Hoffman's and relatively free of phosphorus and algae, a contention backed up in the court's published ruling. They also fear contamination from agricultural runoff on the Hoffman Lake side of the watershed.

Hoffman residents say that the high water in their lake has submerged beaches and killed dozens of trees along the shoreline. Cattail bogs have been lifted from their roots, too, disturbing fish spawning grounds. The bogs, some nearly as big as a river barge, float across the lake, taking out docks and boat lifts as they go.

The feud heated up again last year after the DNR unveiled a plan to create a channel between the two lakes, reversing its decades-old policy of keeping them separate.

Hoffman residents, with their lake in a multiyear cycle of high water levels, had petitioned the agency to let some of their excess water drain into West Mac. The DNR, which owns the bar land, decided to dig a small channel — about a foot deep and 4 feet wide — and allow about 8½ inches of water to drain from Hoffman into West Mac.

The West McDonald Lake Association later filed suit against the DNR to stop the channel.

"We want a level that we both can agree on that doesn't make it continuous water," Todd Yackley, a former president of the West McDonald Lake Association, said last week. "We have no problem with it trickling over the top when it gets to a certain point. That's life and it's been happening for hundreds of years."

David Kienholz, another West McDonald resident, said last week that he hopes the two lakes and the DNR can come to an agreement outside of the courtroom.

"Our hope is that now we can all sit down like adults and try to come to a reasonable compromise once and for all," he said.

John Reinan • 612-673-7402