Ten years of regulating storm-water runoff from new construction projects has not kept phosphorous from leaking into the St. Croix River.
The phosphorous, which commonly comes from fertilizer, is a problem because a pound of it can feed up to 300 pounds of algae, said Dan Baumann, waters program manager in the Wisconsin Department of Natural Resources Eau Claire office.
But rather than attacking the phosphorous problem with a new round of regulations stifling development and adding expenses to home construction, regulators are trying to pinpoint the source. The St. Croix River watershed covers thousands of square miles, so the Minnesota and Wisconsin departments of natural resources will spend two years tracking the sources of phosphorous so the agencies can focus their efforts, Baumann said.
“If we haven’t been doing everything we can in those areas, this gives us the incentive and the focus to do that,” Baumann said.
The Wisconsin and Minnesota DNRs have committed to reducing the phosphorous levels in the river by 20 percent in the next 11 years.
Despite regulations in place for developments near the river, the quality of the St. Croix River has gotten worse, said Sharon O’Flannigan, a sales executive who deals with properties around the St. Croix for Coldwell Banker in Burnet, Minn. She said the deteriorating conditions are the result of new development that makes it harder for rain to soak into the ground.
“The more everything gets paved over and parking lot strips are being developed, it all ends up in the river,” O’Flannigan said.
Municipalities in the area already require that new developments not generate any additional storm-water runoff. New houses built near the river must direct all rainwater away from the St. Croix. The Wisconsin DNR also regulates runoff from farmland, industrial facilities and wastewater-treatment plants.
The storm-water rules require a lot of creative design for new houses, said Bruce Lenzen, president and designer for Bruce Lenzen Homes Inc., Hudson. The regulations, which Lenzen said he supports, add about 1 percent to the cost of building a new house by the river.
However, the opportunities for new construction are limited because most of the lots on the river are developed already, Lenzen said. He said the biggest improvements come when older houses along the river are torn down and replaced.
“There’s only so much property on the St. Croix River,” Lenzen said. “There’s a few sites, but very few that can be developed. So at this point you are dealing with existing structures.”
It is more difficult to make improvements, such as building rain gardens, on existing buildings, said Robert Heise, director of the St. Croix County Land and Water Conservation Department. He said the county’s role in the cleanup will be to educate property owners and developers to get them to step up efforts voluntarily without being required by regulations.
“What we might do is try to look at other practices that we can try to incorporate into development as we move forward,” Heise said. “So, yeah, we’ll be working with the development community. Think of it this way: Everybody in the watershed is a contributor to the problem.”
Baumann said the Wisconsin and Minnesota DNRs will spend $40,000 during the next two years studying where phosphorous in the St. Croix River is actually coming from. Once that is known, agencies can focus on regulation, education or creating incentives for landowners.
“To me, the emphasis is if we can’t protect water quality on such a pristine river, then what’s the chance of doing it somewhere else?” Baumann said. “It should be easier to do here. Everybody is focused on the same goal.”