A group of neighbors is trying to stop a proposed 11-home subdivision of what was the late Doug Dayton's land in Orono, suing the city, developer and watershed district on Wednesday.

In the lawsuit filed in Hennepin County District Court, 13 neighbors say subdivision of the 94-acre estate violates the Minnesota Environmental Rights Act because it would cause "significant environmental degradation and destroy natural ecosystems" of the Big Woods forest.

The lawsuit was filed against the city, developer George Stickney, his company BPS Properties and the Minnehaha Creek Watershed District. It calls the subdivision of the prairie grasslands and dense woods a "slap in the face" to Dayton, the company executive credited with launching Target, and his land preservation work.

"We believe that the environmental impact and degradation as a result of this development is so egregious," said Randy Hopper, the plaintiffs' attorney. "Our focus is on the majestic Big Woods forest. Once that's … harmed there's no way to un-ring that bell."

Preliminary plans to develop the land, one of Orono's biggest remaining parcels of open land, were approved in July. The property sold on Sept. 18 for $5.3 million cash, according to public records, bought by BPS Properties LLC of Wayzata. Final city approval was expected this month and the watershed district, which declined to comment Wednesday on the pending litigation, has received a permit application but hasn't taken action yet. Once approved, construction was expected to start this fall. Stickney also declined to comment on the lawsuit.

On Wednesday night, a judge denied the plaintiffs' request for a restraining order to stop the permits from being issued; that means that the watershed district and city could now move forward with approvals this month. The watershed district has a public hearing tentatively scheduled for Oct. 22; the City Council has regularly scheduled meetings Oct. 12 and Oct. 26.

"It's just a shame to see how it's turning out," Dayton's son, Bruce Dayton, said Thursday, adding that his father only wanted to see two other homes built on the property. "The 40 years of work he did establishing the prairie is going to be heavily damaged. … It was supposed to be his legacy."

Doug Dayton, the grandson of Dayton's department store founder George D. Dayton and uncle of Gov. Mark Dayton, bought the land just north of Wayzata some 50 years ago. When he died in 2013, his widow, Wendy Dayton, vowed the land wouldn't be sold to developers, and announced plans last year for an 83-acre conservation easement.

When word leaked the property was coming to market, developers pounced. It hit the market last year for $5.9 million, far less than its worth as a redevelopment project. The land has a 6,600-square-foot, six-bedroom house tucked into the side of a hill. It overlooks shoreline on Mooney Lake, a small, shallow lake dotted with about 50 homes of some of the Twin Cities' most prominent families — from the Daytons to the MacMillans of Cargill fame — and includes parts of Plymouth, Medina and Orono.

On Doug Dayton's property, he restored fields to what they may have looked like before it was farmland and built trails through the dense forest. The Big Woods once covered as much as 6,500 square miles of eastern and central Minnesota, but only an estimated .01 percent of the original forest remains today, some of which is on the Dayton land.

This summer, plans changed and Stickney proposed Mooney Lake Preserve and buying the property. Just after the closing, Stickney, an agent with Coldwell Banker Burnet and a principal with BPS said that the 11 lots would include seven lakeshore lots and four off-lake lots, with an average lot size of 3.18 acres; the property includes slightly more than 94 acres, more than half of which will remain in its natural state. City leaders have said that Stickney could have gotten at least 30 homes on the property and choose instead to preserve some of it. The project has been contentious among city leaders, too, with a debate over what's more important — preserving the restored prairie or the mature forest — and as a result, initial plans were revised, moving one lot from the woods to the prairie.

However, Hopper called the plans a "slap in the face" to Dayton and an "unconscionable" action. The lawsuit asks the court to prohibit the council from approving the proposed plat, the watershed district from approving ecological permits and the developer from any construction or development. The suit also asks the court to order the council to initiate an environmental review.

The plaintiffs, who all live along Mooney Lake, are Anne Healy, Audra Nestler Holm, Eric Lundeen, Karen Lundeen, Jeff Mendeloff, Jennifer Mendeloff, Marilyn Miller, Joyce Pokorny, Karl Pokorny, Karen Reed, Mark Reed, Rebecca Ribich and Tobias Shapiro.

"They're not doing it for economic reasons," Hopper said, "but because it's the right thing to do."