2016 sees clearer water on Madison’s lakes

Clean Lakes Alliance volunteer monitors see improvements and mixed results

MADISON, Wis. — Clean Lakes Alliance has released results from the 2016 monitoring season on lakes Mendota, Monona, Wingra, Waubesa and Kegonsa. Over the past three years, the volunteer-based program has grown into an extensive 70-site effort to track water conditions near the shore, where most people interact with our lakes.

The Findings

Near-Shore Monitoring :: Memorial Day – Labor Day

Average clarity (in cm)*
2015 2016
Mendota 85 96
Monona 94 100
Wingra 107 102
Waubesa 90 94
Kegonsa 86 77

*near-shore turbidity tube measurement

Average near-shore water clarity on lakes Mendota and Monona increased compared to 2015, by 11 and 6 centimeters* respectively. Near-shore clarity was down on Lake Kegonsa, however clarity on lakes Wingra and Waubesa were about the same. This provides a contrast to 2014 and 2015, when water quality suffered due in part to rain-driven runoff.

Reports of blue-green algae also significantly decreased on Lake Mendota. Last year there were 27 blue-green algae reports, compared to just five this year. In fact, blue-green algae blooms were down on all lakes, except for Lake Wingra.

“Water clarity this summer helped show people what healthy lakes CAN look like if we make them a top priority,” said Clean Lakes Alliance executive director James Tye. “If we continue to push for changes in our watershed, clear water can be a constant and not just something we witness under only perfect conditions.”

Factors in Our Favor

  • The mild winter gave the algae-grazing water flea Daphniaa head start this year, leading to larger populations that kept green algae in check (Daphnia do not control blue-green algae).
  • An early thaw meant farmers were able to get crops in the ground earlier. The early planting meant there was less chance for a rainstorm to wash manure off of frozen ground – which is a worst-case scenario for phosphorus runoff to the lakes.
  • Together as a community we have diverted 9,200 pounds of phosphorus from our lakes as part of community-wide efforts to address nutrient pollution that damages water quality.

Beach Monitoring is Critical

Data from volunteer teams found it is impossible to predict clarity at beaches using measurements taken in the middle of the lake. This underscores the importance of Clean Lakes Alliance’s network of citizen monitors who report findings on lakeforecast.org. These monitors were stationed at every public beach on all five lakes in 2016. Next year the goal is to increase the frequency of beach monitoring, giving the public even greater confidence in beach conditions.

Learn more

Join Clean Lakes Alliance on Thursday, November 10th at The Edgewater as we present 2016 monitoring results. RSVP.

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