Lake Byllesby water level to be lowered after Labor Day for dam repairs

Rumors swirled on the shores of Lake Byllesby when residents heard the county planned to lower the lake by nearly nine feet for dam repairs.

Is it happening soon? Will this ruin boating season? Cannon Falls residents began calling their county commissioner with concerns.

So when Dakota County staff recently announced that they do not plan to lower the water level until after Labor Day, boaters and lake-goers breathed a deep sigh of relief.

"For the bulk of the lakeshore owners, they had no problem with that," said Earl Benson, president of the Lake Byllesby Improvement Association.

Turnout to a biannual meeting of the association the other week spiked, he said. Residents wanted to hear if the rumors about the drawdown were true.

The county needs to repair concrete that has cracked on the aging Byllesby Dam and decided to do so this fall, when flooding is less common, Water Resources Supervisor Tom Berry said.

County staff also recognized that if they start the work before Labor Day, "that just obviously cramps their style," Berry said of the more than 120 property owners around the lake and other visitors.

However, that timeline hinges on a Minnesota Department of Natural Resources study of mussels in the lake. If the DNR finds threatened or endangered mussels that need to be relocated that could change date for the drawdown, Berry said.

Mike Davis, an aquatic ecologist with the DNR, said the department's work should be done well before the fall.

"If there needs to be some sort of mitigation for impacts to mussels, we can take care of that pretty quickly," Davis said. "We don't expect it will impact the drawdown at all."

If officials are able to stick with the anticipated post-Labor Day drawdown, then the boating season will be cut short by about four weeks, Benson said.

The lower elevation will have the greatest impact on duck hunters, he said, because they will not be able to use access ramps and "a good share of the places they normally hunt will be high and dry."

A slab of concrete on the dam is leaking. The slab is from 1911 but was patched in 1987. The repairs this fall are a long-term solution that should protect and reinforce the face of the dam for another 30 to 40 years, according to county documents.

"If it goes as planned the lake residents are fine, knowing what the outcome will be — preserving the dam," Benson said.