Next spring, the barn swallows that for years have swooped and pooped in the Richfield park shelter that is the site of the city's popular farmers market will find their favorite nesting sites blocked by netting.

But they might not have to go far to find a new site to raise their chicks.

In a solution to an emotional issue that may satisfy birders who wanted the swallows left alone to raise their young, the city is proposing to work with volunteers to build a swallow-friendly nesting structure in Veterans Park.

"We haven't finalized it, but it would be in a place where people are not eating or playing or anything," said Jim Topitzhofer, Richfield director of recreation services.

The barn swallows have been a fixture in the park picnic shelter for years, building their cup-shaped mud-and-fiber nests in the rafters. But in recent years some picnickers complained about waste dropping from the ceiling as they ate. Others were frightened when the birds swooped over their heads.

The city refunded rental fees for some picnickers who claimed the birds had ruined their outings. City officials also decided that letting birds drop their waste in the shelter was a potential health issue.

So early this year, the city tried to scare off the swallows by playing a loud tape of screeching raptors in the shelter. Someone cut the speaker wires. But even when the sound was working, the swallows did not leave.

Did city break the law?

City staff then began removing the nests, which resulted in complaints from at least one birder that the city was violating federal law by destroying nests with eggs in them. The city denied the allegations.

Last week, the Richfield City Council approved a contract for $11,420 to install netting on the underside of the shelter roof. Topitzhofer said the netting will cover all of the ceiling, with zippers that allow access to lights and areas that need maintenance. The netting is guaranteed for at least 10 years.

So the barn swallows that return next spring will need a new nesting site. Topitzhofer is proposing that service groups, perhaps Boy Scouts, help build a nesting structure that could be placed near the park's lake and away from picnic areas. The structure could have a fake chimney to provide a nesting site for chimney swifts, another bird that has been losing nesting sites in metropolitan areas.

"We're still on the migratory route, and we know birds will be coming here every year and looking for a place to nest," Topitzhofer said. "We want to do the right thing environmentally."

He said he will talk with birders about the project and explore getting a grant or donor money to pay for it. He said he hopes the structure can be built this winter so it is ready when the birds return next spring.

Mary Jane Smetanka • 612-673-7380 Twitter: @smetan