Yahara WINS update: presenter says watershed approach is more cost-effective than plant upgrades

Mike Gilbertson, watershed programs coordinator at the Madison Metropolitan Sewerage District, told the Waunakee Village Board on Aug. 4 that Yahara WINS has delivered measurable phosphorus reductions and remains a cost-effective way for municipalities to meet TMDL obligations.

“We're committed to achieving significant phosphorus reductions, meeting rigorous DNR standards, and creating lasting benefits in the entire watershed community,” Gilbertson said during a presentation to the board. He described the program as a pooled, watershed-based approach that pays for on-the-ground practices—especially in agriculture—that the district credits toward the TMDL for the Yahara watershed.

Gilbertson said the program surpassed its 2024 annual reduction goal by 12% and kept almost 60,000 pounds of phosphorus out of the Yahara watershed in 2024. He said the village of Waunakee has paid a little over $218,000 into the program and that, within the program’s locally defined reaches 63 and 64, the district attributes nearly 41,000 pounds of phosphorus reductions since full implementation began in 2016. Gilbertson also said implementing partners and private producers have contributed significant matching resources to multiply the program’s reach.

Gilbertson contrasted the watershed strategy with augmenting treatment at a sewage plant, saying additional plant-level treatment is far more expensive per pound reduced. He cited a district estimate that building extra treatment capacity at the plant would have cost on the order of $210 million (with large ongoing maintenance costs), while the pooled, practice-based approach yields much lower per‑pound costs. He offered a rough local comparison: reducing roughly 400 pounds of urban-source phosphorus in Waunakee on its own would be costly (Gilbertson estimated a multi‑million dollar price), whereas many agricultural best-management practices the program funds can reduce phosphorus at a substantially lower cost per pound.

Gilbertson said Yahara WINS is approaching the second half of a 20-year implementation period with a watershed goal of 100,000 pounds of reduction by 2036. He described ongoing work with monitoring partners, including the U.S. Geological Survey, expanding implementing partners (such as Yahara Pride Farms, Dane County Land Conservation Department and Rock County), and pursuing federal grant opportunities. He also invited municipalities and residents to propose urban pilot projects—examples he gave included rain gardens and cost-share programs for urban runoff controls.

Board members thanked Gilbertson and asked follow-up questions about future Madison Metropolitan Sewerage District rate increases; Gilbertson said rate-setting is a district matter and he could not provide a forecast but noted the topic is being discussed at district commission meetings.

The presentation and the board’s Q&A closed with Gilbertson offering to follow up on questions and to engage on potential local project ideas.