Most of us who spend time on lakes know they can “green up” as they warm up. Excess phosphorus generates that not-so-healthy green bloom.
The Yahara watershed is trying something novel. The watershed surrounds Madison, Wisconsin and has at its center the iconic lakes Mendota and Monona. Even with a state capitol and population of 370,000, it’s primarily agricultural.
The new approach — led by the Madison Metropolitan Sewerage District, in partnership with Dane County, Wisconsin DNR, and local governments — works this way: Rather than build three new wastewater treatment plants at a cost of $270 million, why not spend less than half that to tackle the problem where it starts?
The coalition pooled $2 million to pay for approved, phosphorus-reducing measures. A pilot project that began in 2014 targeted the biggest loaders. Full-scale implementation of the 20-year pact began this year. Results will be demonstrated though ongoing monitoring, and lakes that aren’t green anymore.
By Carrie Jennings, research and policy director
