Arboretum and Community Partners Discuss Ways to Reduce Salt Contamination in Lake Wingra

Big Spring on the north side of Wingra Woods

Big Spring in Wingra Woods

This spring, two meetings at the Arboretum brought together stakeholders from the Lake Wingra watershed with the overarching goal of reducing the amount of salt entering Lake Wingra – a water body with chronic chloride contamination. The planning team aims to increase the awareness of this issue and encourage the adoption of winter maintenance best practices throughout the watershed through a stakeholder-driven process.

The meetings were organized in partnership with Wisconsin Salt Wise and Dr. Hilary Dugan’s lab in the Center for Limnology, and they were attended by representatives from the City of Madison Streets Department, Dane County Highway Department, Edgewood College, Friends of Lake Wingra, Glacier Landscaping, Henry Vilas Zoo, St. Mary’s Hospital, Strand Associates, and Temple Beth El – covering a broad range of locations, lot sizes, and community services within the watershed.

A display about chloride contamination and sampling methods of springs around Lake Wingra (Photo: Julia Whidden)

Meetings began with an overview of salt levels in the lake, including historical data dating back to the 1940s collected by the Center for Limnology, recent data of surface water chloride levels collected by graduate students in Dr. Hilary Dugan’s lab, and ground water chloride levels collected at eight springs around Lake Wingra from the Arboretum’s Lake Wingra Chloride Springs Monitoring citizen science project. These data presented a compelling case of increasing salinity in Lake Wingra that correlates to the expansion of urban development in the watershed and the consequent increasing ecosystem pressures affecting this highly urban lake.

Next, Allison Madison from Wisconsin Salt Wise shared various best practices for winter maintenance that can be adopted by both small and large organizations to minimize how much salt enters the watershed. Practices include sweeping up excess salt, recognizing the efficiency and limitations of road salt and deicers across temperature ranges, ensuring the best tools are being used, and sharing educational videos and other resources that are available on their website and YouTube channel. In addition to destructive ecosystem impacts, Allison also outlined economic reasons to reduce salt usage: every dollar worth of salt used can cause ten dollars of damage to city infrastructure, including roads, sidewalks, bridges, landscape, and vehicles. Her overarching message? Smart salting practices are better for everyone!

Allison Madison of Wisconsin Salt Wise presenting about winter maintenance best practices for salt reduction. (Photo: Maddie Smith)

The meetings concluded with an hour of group discussions and action step planning for individual organizations as well as the broader watershed. Each organization shared their current practices, the barriers they face to reducing salt usage, and their goals. Discussion points included oversalting and concerns about lawsuits and liability, the need for better data collection and sharing citywide, more opportunities for training and education, and a consensus that meetings like this are valuable for raising awareness and providing a springboard for action.

The planning group hopes to reconvene with stakeholders before winter and provide more opportunities for the community to learn about and protect this freshwater resource. Allison Madison summarized, “The two Lake Wingra Salt Wise stakeholder events were collaborative and impactful. Key watershed stakeholders helped identify individual and collective action steps to address local freshwater salinization. I can’t say that I’m excited for next winter, but I am excited to continue to support these efforts in the seasons ahead.” The group also gives special thanks to Badger Volunteers and Friends of Lake Wingra for providing additional planning and financial support for these meetings.

—Julia Whidden, Arboretum citizen science coordinator