When Jim Tauer bought his home in the Lakes of Blaine development, the pond at the foot of his sloping back yard was a selling point for which he paid extra.

But last spring, record rains turned the man-made pond into a costly problem. Rain and runoff filled it to the brim and caused erosion, leaving a small cliff at the shoreline. Tauer and some of the other two dozen homeowners whose yards back up to the pond fear they'll lose even more ground in next spring's rains and runoff.

"I thought [the pond] was part of the beauty of the landscape," Tauer said. "I thought they put all these in for aesthetics. ... I paid a premium to be on this pond. I think it was about $10,000."

He said he and neighbors were never told that it was built to collect and filter stormwater.

Their pond is one of about 300 dotting newer neighborhoods across Blaine. They've become ubiquitous in more recent suburbs. Woodbury has nearly 550, Maple Grove about 380.

The ponds were not meant to look pretty or to be clean and pristine, city scientists and staffers say. They were built to comply with federal law.

Since 1994, the U.S. Clean Water Act has required new developments to trap pollutants, said Michael Findorff of the Minnesota Pollution Control Agency, which oversees stormwater pond construction and permitting.

"Realtors say it's waterfront," he said. "Really, it's a stormwater treatment device."

In older neighborhoods without ponds, runoff laced with lawn chemicals, grass clippings, sand and trash goes straight into storm sewers, then into lakes and streams.

Newer neighborhoods added ponds to prevent that. As the ponds age and require dredging, city officials are spending more money to maintain them and to educate residents about their purpose.

Blaine spends $1.1 million on its stormwater program to meet federal requirements, while Woodbury spends more than $800,000 and Maple Grove an estimated $1.5 million annually. Cities pay to maintain them as stormwater basins, but ownership varies from pond to pond. Cities own some, neighborhood associations own some and, in some instances, the homeowners bordering ponds own them.

'Not going to be blue water'

Initially, many developers built ponds close to homes and bordering back yards, marketing them as a little slice of serenity in the suburbs, and many homeowners enjoy the birds and wildlife they attract. But years later, homeowners and city officials have realized the proximity isn't always ideal.

"We constantly get people calling and saying their pond is not clean," said Rick Lestina, water resources engineer for Maple Grove. "It's not going to be blue water. They are going to have to understand they are used to clean up water."

Some people remove native vegetation around the ponds, which can cause problems.

"People put lawn right up to the water's edge," Lestina said. "The best thing you can have around the pond is vegetation, but people often don't want that. They see it as weeds. … But if maintained properly, native grasses can look nice."

When a city brings in heavy equipment to do maintenance, lawns sometimes get torn up. Cities have taken steps to mitigate that, including having some ponds built on outlots on the edge of developments.

Each winter, Woodbury does full pond dredging on three to seven ponds. Doing it then "creates the least disruption for the wetland and pond, and it really cuts down on damage if we have to disturb someone's yards," said Woodbury environmental resources coordinator Sharon Doucette.

Who should pay?

In Blaine, the mayor and a City Council member met with Tauer and his neighbors, toured their pond's shoreline and had crews examine how the pond is functioning.

"We had record rains in June," said Blaine stormwater manager Jim Hafner. "Everything was saturated. There was no place for water to go," resulting in erosion.

The makeup of the soil, originally peat, contributed to the problem, he said. Builders hauled in sand to build homes but left the peat on the pond bed. The erosion occurred where the sandy soil meets the peat.

One contractor estimated that fixing the shoreline could cost $300,000 to be split by six homeowners, including Tauer.

"I almost had a heart attack," Tauer said of the estimate. "It's more than my home alone is worth. ... The bottom line, is I don't think ... homeowners should be responsible for this." The city owns the pond and should pay for it, he said.

Blaine Mayor Tom Ryan said the situation is unusual and unfortunate, but not the city's problem.

"The city's liability is nil here, in my opinion. We didn't do it," Ryan said. "It isn't probably what they dreamed when they came in. That's what you get when there are waterways. Ten years after the construction, we don't have any responsibility for that, nor does the builder."

The mayor isn't unsympathetic, though. He knows firsthand the hassle a stormwater pond can be. Last summer, a pond owned by Anoka County that borders his property filled with water for the first time in decades, killing a dozen of Ryan's large pines.

"They were 25 feet high," Ryan said. "That is a fact of life. I will replace them. I will start over.

"The next time, I will learn and plant higher."

Shannon Prather • 612-673-4804