Planned Wetland Project Pays for Itself

Milwaukee County Parks Map of future wetland site.

Milwaukee County Parks is working on a wetland mitigation project that will create a new wetland on the parkland at no cost to the county and will pay for its own maintenance.

The way it works is this: the Wisconsin Department of Natural Resources will commit $155,000 to create a new wetland on 20 acres of county-owned farmland that has been too boggy from stormwater to farm in recent years, according to Erica Goblet, contracts manager for Milwaukee County Parks. Once completed, the DNR will sell a financial instrument, regulated by U.S. Army Corps of Engineers in Wisconsin, called a wetland mitigation credit to finance the long-term maintenance of the wetland.

Farmers whose agricultural practices impact wetlands can buy these credits, which are then used for the long-term maintenance of these new wetlands and other natural areas. The process is called wetland mitigation banking.

“Essentially, wetland mitigation banking uses a market-based approach to restore, create, or enhance wetlands in one place to compensate for unavoidable impacts to wetlands at another location,” the parks department said in a report. “If a farmer wishes to mitigate impacts to wetlands they can purchase a mitigation credit from a credit holder, in this case the County.”

The site chosen by the DNR and county parks is near the intersection of E. Puetz Rd. and S. Nicholson Rd. in the Oak Creek Parkway, located in the city of Oak Creek. The land is currently leased to a farmer for approximately $2,200 a year, Goblet said. The farmer has been notified of the project and will have one more year to work the land.

The county structures its agricultural leases so that they can be terminated at will, Goblet said, because, “With our agricultural lands, the goal always is to eventually return them to natural areas.”

“The farmers are never thrilled,” she added, but they’re given notice at least one farming season ahead.

The county has reforested hundreds of acres of former agricultural land, Goblet said, but hasn’t had funding for a project like this.

Wetlands are critical to ecological health and diversity in Milwaukee County, according to the parks report. “They provide essential breeding, resting, and feeding grounds and escape cover for many forms of fish and wildlife,” the report states. “Wetlands also contribute to flood mitigation, may also serve as groundwater recharge and discharge areas, and help to protect downstream water resources from siltation and pollution by trapping sediments, nutrients, and other water pollutants.”

Once the new wetland is constructed, parks will place the site under a conservation easement protecting it in perpetuity. At that point, the wetland mitigation credits can be marketed. These credits can fetch anywhere from $10,000 to $30,000, according to parks, depending on the market. And a general rule states that for every 0.5 to one acre of wetland created, one credit is generated. So the wetland in Oak Creek could generate 20 to 4o credits for the county.

It’s estimated that it will cost approximately $2,000 annually to maintain the wetland, Goblet said. The DNR requires at least 50% of all revenue from the mitigation credit goes toward long-term maintenance. Parks plans to use the remaining 50% to pay for general support of the county’s natural areas.