Residents and officials can agree they want better water quality at Anderson Lakes – the question remains on how to get there

By Leah Shaffer

The prospect of losing a lakeside view, even temporarily, would be startling to any landowner. The challenge for local officials is to convince enough Anderson Lakes shoreline owners that such a loss is worthwhile, and that the water will return.

“We’re kind of at a real tricky point right now,” noted Kevin Bigalke, administrator for the Nine Mile Creek Watershed District.

At issue is a plan to draw down northwest and southwest Anderson Lakes in order to kill off an invasive plant called curlyleaf pondweed. Many nearby residents however, would prefer that a chemical treatment be used on the lake instead.

“I think that the largest obstacle to the drawdown for us is that if we had a water source to refill the lake, I think we’d probably be on board with this,” said Linda Goetz, addressing homeowners’ views during a recent meeting of the Watershed District Board.

Goetz said that a majority of the landowners still “prefer the chemical.”

In an interview last week, Bigalke explained that for either approach, the watershed district will need a permit from the Department of Natural Resources.

 “… and we need to have all of the lakeshore owners to agree with the treatment,” he added.

Since not all the owners want a drawdown, there’s no guarantee they can get that permit. Yet, to get a permit for the chemical treatment, the Three Rivers Park District (which owns about 90 percent of the shoreline) would also need to agree. That goes against its own policies.

One of the landowners, Mike Bendtsen, said he personally would prefer a drawdown, “but I support either.”

What he wanted to emphasize is that the more educated you are on the issue, the better you can make your own decision, he said.

 “I am concerned the solution might be nothing,” he said.

Last resort

In previous meetings related to this issue, residents brought up a number of concerns they had with the drawdown, including plans to not restore lake levels to the current level, the effects a drawdown might have on foundations, the noise associated with water pumps, and the need for a lake refill contingency plan.

But, from the perspective of both the city of Eden Prairie (which originally petitioned the district to start the water quality improvement project) and the Three Rivers Park District, the use of chemicals to treat the lake is a last resort.

“You’re introducing chemicals into the system when you don’t need to,” said Leslie Stovring, the city’s environmental coordinator.

She said the chemical treatments do not address some of the other issues, like consolidating the sediments to provide a better surface for the vegetation.

 “It doesn’t help bind up the phosphorus in the sediments,” she said. “So you have to do another treatment for removal of the nutrients, on top of the herbicide.”

According to Stovring, treating the lake with an herbicide could take at least three years, while, it is estimated it would take one and a half to two years for the lake to refill.

Though curly leaf pondweed affects many city lakes, Anderson Lakes could actually be a candidate for a drawdown because it’s so shallow. Stovring said the lake has dried up in the past.

One of the issues that Goetz brought up is the lack of experience the Three Rivers Park District has with drawdown.

But, according to Three Rivers Park District Water Resources Manager John Barten, district officials know that drawdowns work.

Drawdowns elsewhere in the metro area such as Maple Grove and in Scott County “have been fairly successful,” Barten said.

Meanwhile, at Medicine Lake, which has been treated with chemicals for three years, “we’ve documented that there’s been resurgence in the growth of curly leaf pond in pretty extensive areas of the lake.”

According to Barten, the main reasoning for use of a drawdown comes from park district policies. According to those policies, they need to explore cultural physical and biological control options before using the chemical option, he said.

Along with killing the weed, he noted that “almost without exception, when you do a drawdown of a basin like this, you get a real resurgence of native plants.”

It’s very beneficial to wildlife, he noted, “so we see that as a real plus.”

The third issue, he said, is the cost. The drawdown is estimated to cost $125,000, he said. The chemical treatment could cost as much as $1 million, if it takes five years to treat the lakes, he estimated.

He noted that people are obviously concerned with what will happen with a drawdown.

“That’s definitely a hurdle that will have to be overcome through some discussions,” Barten said

But, he added, if they can get through the emotion and look at the hard numbers, “I’m hopeful that we can come to a consensus on this issue.”

Currently, there’s still time to make comments on an environmental assessment worksheet for the project (available at www.ninemilecreek.org/EPL/htm).

According to Bigalke, the comment period runs through Aug. 15. At its Aug. 29 meeting, the Nine Mile Creek Watershed District Board of Managers will need to decide whether or not there is a finding of no significant impact with the EAW. At that same meeting, they’ll move into the discussion and deliberation as to what would be the option for treatment on the lake.

Bigalke said there will be discussion amongst staff and residents to look at some other options that might strike a balance and satisfy all parties along with the objectives of improving the water quality.

“It’s been an interesting process,” he added. “I think we’ll be able to strike a compromise.”