Jim Weninger has spent his life on the shores of Spring Lake. His parents first rented a house there around the time of his first birthday, and as an adult he met his wife, Liz, while water skiing.

The spot between the city of Prior Lake and Spring Lake Township draws residents in search of lakeshore living without the hustle and bustle of the water of nearby Prior Lake.

“The lake is not as highly utilized,” Weninger said. “It’s much more casual.”

But some residents are worried that the lake’s character is changing. Recently, the Spring Lake Estates development on the lake’s northern side got city approval to nearly double its number of boat slips. And under current city ordinance, it could have even more.

Resident pushback has prompted the City Council to take another look at the ordinance, adopted in the aftermath of a public outcry in 2013 about a proposed marina on Prior Lake.

The ordinance allows one boat slip per 12.5 feet of shoreline — for Spring Lake Estates, that means up to 75 slips.

“There is a finite number of boats that a lake can handle,” Weninger said. “When do we start saying ‘Hey, enough is enough’?”

Pollution, safety worries

In raising concerns about increased boat traffic, residents have asked questions about everything from swimmers’ safety to potential pollution.

The Minnesota Pollution Control Agency has identified Spring Lake as “impaired,” because of phosphorus pollution that can affect recreational usage.

To mitigate that, the Prior Lake-Spring Lake Watershed District started a three-part alum treatment in 2013 to reduce phosphorus levels. So far, it’s been effective.

“For the first time ever, we could actually see the bottom of the lake in the spring,” said Spring Lake resident Christian Morkeberg, who’s worked with the watershed district.

Chris Zadak, watershed project manager at the MPCA, said the lake’s phosphorus levels started rising in the 1970s. As with many lakes, the change came from a variety of factors, most related to overall development around the lake.

Residents say they’re worried about boat traffic stirring up sediment and increasing phosphorus levels, erasing the results of the alum treatment. But Zadak said it’s tough to guess what will happen.

“More boat traffic can potentially cause more release of phosphorus, and that phosphorus can lead to more algae growth,” he said. “Is that counteracted by the alum addition or does the boat traffic shorten the life span of that? I can’t say with certainty.”

Morkeberg, who swims, kayaks and canoes on the lake, said he’s worried about an overall shift in its ambience.

“If you want to profile your community as an attractive place to live, do you want a clean lake or a dirty lake? It’s pretty easy, right?” he said. “Do you want a lake that’s full of speed boats, or do you want to have it a little bit quiet, a little bit under control?”

‘We’re not going back’

A 2002 annexation agreement between the city of Prior Lake and Spring Lake Township set the number of boat slips at Spring Lake Estates at 30.

“It didn’t say that this would be forever the limit,” said city administrator Frank Boyles. “But I think most people made that assumption.”

Spring Lake Estates resident Sara Kalis said she understands the traffic concerns but doesn’t expect the added boat slips to have a significant impact on the lake.

“I would be surprised and shocked, even, if there were ever a time when even half the boats were out,” she said.

Using the formula established in the recent ordinance, Spring Lake Estates already has upped its number of boat slips to 54. That number won’t increase during the time the City Council takes to reconsider the ordinance, but it won’t drop, either.

“That’s a done deal,” said Mayor Ken Hedberg. “We’re not going back.”

Without any dramatic changes on the horizon, residents who’ve spoken out say they’re hopeful for a solution that will maintain the environment that drew them to Spring Lake to begin with.

“It’s definitely gotten busier … but it’s still not like Prior Lake,” said Mike Baldwin, who moved from Prior Lake to Spring Lake 27 years ago. “But it only takes one or two more boats to make it worse for everybody.”