- Explore Parks
Strategically located at the head of Madison's lakes, Cherokee Marsh acts as a living sponge. It filters upland runoff, using excess fertilizer to grow marsh plants, and slowly releasing cleaner water to the lakes below. Cherokee Marsh is the largest wetlands in Dane County. It is used by thousands of students each year for environmental education. The Mendota Unit has 0.6 miles of trails.
The City of Madison has lost over 640 acres of wetland in Cherokee Marsh, along the Yahara River, since 1849. These wetlands "floated up" and were lost when the water level of Lake Mendota was raised about 4 feet in 1849 with the construction of a dam at nearby Tenney Park. A new dam built shortly after 1900 raised the lake level another 3 feet. Many times these floating sedge mats, or bogs, will break off and float away. Recently, the Madison Parks Division received a $10,000 Lake Protection Grant to fund experimental wetland restoration techniques.
Earlier this year the city analyzed some historic 1937 air photos of the upper Yahara River. By comparing to current air photos of the area, it was determined that approximately 275 acres of high quality wetlands have been destroyed since 1937. The Parks Division Staff then did additional research using the 1834 Public Land Survey Records for Wisconsin. These records documented the width of the Yahara River at several points where section lines crossed the river. This information enabled the staff to calculate wetland losses prior to 1937. The combined wetland losses since the first dam was installed in 1849 are more than 640 acres (1 square mile). With such a large loss, the importance of this project is obvious, and this is where the city volunteers come into play.
Volunteers will be involved in experimental techniques that involve establishing submergent and emergent wetland plants in the Yahara River to help protect the fragile "floating shoreline". By establishing these plants in front of the "floating shoreline" they will help buffer the effects of erosion and in effect will create a vegetation breakwater. Wind generated waves and foraging carp are the two most destructive erosive forces working against these fragile wetlands. Various types of wire fence enclosures will be installed to protect the plants from carp, muskrats, and geese.
The citizens of Madison have shown that they are willing to get dirty and wet in trying to save this lost marshland. Not only will this project help protect and enhance wildlife habitat, but will also trap nutrients before they reach Lake Mendota.