The detention pond design municipal officials say is the cheapest way to satisfy state requirements would be outlawed under the latest proposed runoff rules.
“You just start adding things up higher and higher if you don’t have that option on the table,” said John Neumeier, engineer and GIS specialist for Kaukauna.
The Wisconsin Department of Natural Resources is revising rules that require cities prevent sediment from washing into local waterways by channeling runoff into ponds or green space. Municipalities such as Kaukauna have proposed building the detention ponds in the middle of waterways, but the proposed DNR revision would prohibit the design, known as in-line ponds.
DNR officials have said the in-line ponds attract carp that come to breed, stir up the sediment, let it flow downstream and defeat the purpose of detention ponds.
Friday was the deadline for comments on the rule revision. About 650 written comments had arrived by Friday afternoon, said Carol Holden, DNR runoff management section education coordinator.
She said the DNR will review and respond to the comments and send a proposal to the Wisconsin Natural Resources Board in June.
Among the comments received by the DNR is a request by the League of Wisconsin Municipalities to allow construction of the in-line ponds.
Jonathan Ela, chairman of the Natural Resources Board, said he is open to listening to cost concerns about the rules but would not comment on whether he thinks the rules should be modified.
The DNR has eased some cost concerns about the rules by capping the amount of money municipalities must spend each year to satisfy them, said Curt Witynski, the league‘s assistant director. The rules would not require a municipality to spend more than 37 cents per $1,000 in property value a year on projects to control storm water.
The spending cap helps, but the state should not forbid the in-line ponds, which offer municipalities the chance to build ponds without having to acquire private land, Witynski said.
“We commented on that to try to retain some flexibility in that area,” he said, “because when you look at it, it is one of the least expensive options.”
The DNR last year reported it would consider permitting the in-line ponds, so Kaukauna engineered and bid out a project for a creek in a local park. But the DNR refused to issue a permit for the project, which would cost $294,878, Neumeier said. The city appealed the decision and is awaiting a hearing with DNR staff in Madison, he said.
Kaukauna considered projects other than the in-line pond to control storm water, Neumeier said. But the pond was the only option the city could afford that would meet the state’s requirement that cities reduce by 40 percent the amount of sediment entering waterways through runoff.
Other options included using eminent domain to acquire land to build a new pond or building smaller basins throughout the city to collect water. Neumeier said the city did not estimate specific costs for the other options after deciding they would be more expensive than the in-line pond.
“It’s going to make the difference of if and when we can meet the DNR’s 40 percent requirement,” he said.