Bike Tours of the Lake Mendota Watershed Written by Harry Read

Contents

No matter where the watershed, water quality is a direct reflection of land use. These bicycle tours were organized with this principle in mind, to help citizens learn about our watershed and what is being done to protect and improve water quality. Along the way, we're sure you'll enjoy the impressive scenery and develop a deeper appreciation for our area. There are five tours: four follow major tributaries of Lake Mendota and a fifth circles the lake itself. The tours can be taken by car or bicycle and range from 21 to 50 miles. Each tour is rated for difficulty, so cyclists can match route to ability, and shortcut options are identified.

This Land of Ours

Glaciers shaped the Lake Mendota watershed and formed all four lakes in the Yahara chain. The moving ice bulldozed the landscape, widened valleys, smoothed hills and created poorly-drained areas where wetlands formed. Debris acted as dams across the Yahara River, creating the lakes. Ice grinding on bedrock left the Horicon Till, a thick layer (over 100 feet in places) of "drift" (a mixture of stones, gravel, sand and silt) called "ground moraine" that blankets the land. Beneath the moving ice, hills were smoothed into elongated teardrops (called drumlins) oriented in the direction of the ice movement. Meltwater draining through the ice left conical piles of debris called kames. These glacial landforms are common in the watershed.

Humans first inhabited the watershed about 12,000 years ago, living first by hunting and gathering and more recently by agriculture as well. The Native Americans left behind many artifacts, including hundreds of earthen mounds, many shaped like animals. By periodically setting fire to the land, they shaped the prairie-oak savannah landscape that greeted the European settlers. When European-style farming began in the 1830s, dramatic transformations in the land and water began. Soil eroded from the new farms fertilized the lakes. People began to notice nuisance algae blooms in the 1880s. The problem was exacerbated by draining and filling wetlands, which formerly kept sediments and nutrients from flowing into the lakes.

As the 20th century progressed, water quality in our watershed declined in direct proportion to population growth. Sewage from growing towns and cities, along with manure and fertilizers running off from farms added bacteria and more nutrients. As urban and suburban areas grew, so did the area covered by streets, parking lots, roofs and sidewalks. This has increased the amount of runoff, eroding waterways and carrying contaminants directly to the lakes.

Priority Watershed Work to Control Runoff

Recent years have brought progress, and new challenges. Municipal sewage is treated and mainly diverted away from the lakes. Wetlands are better protected. However, population is increasing rapidly, generating much new construction while farms support ever greater numbers of livestock. Recognizing these trends, local and state officials in 1994 worked to include the watershed in Wisconsin's Priority Watersheds Program.

This partnership between state and local governments, farmers, developers and citizens helps set pollution reduction priorities, targeting non-point source or runoff pollution. This kind of pollution includes excess nutrients, soil, pesticides and toxic chemicals that are washed into the water from farms, fields and streets. It is the greatest threat to surface waters.

Adoption of innovative farming practices, stormwater management techniques and construction site erosion control measures, combined with street sweeping and citizen cooperation in taking care of yards and pet waste, promise improvements in water quality. Promotion of these practices is one focus of the Priority Watershed Project. Some farming and construction site management practices that reduce nutrient and sediment runoff that may be seen on the bike routes are described below:

Grass waterways are natural drainage ways shaped and seeded with grass to prevent runoff water from causing gullies and washing away topsoil.

Contour farming means planting crops across rather than up and down the slopes of fields. This slows water runoff, increasing infiltration and reducing erosion. (see graphic)

Contour stripcropping combines contour farming with crop rotation. Alternating strips of corn or soybeans are planted along with soil conserving crops such as oats, grass or hay. Not only does planting across the slope rather than up and down slow water runoff, the strips of oats, grass or hay act as buffers to soak up nutrients.

Streambank fencing keeps livestock out of streams. Livestock crossing the streams can lead to erosion on the banks, and pollution. (see graphic)

Manure storage structures hold manure until conditions are appropriate for field application. Proper storage and application keep manure out of surface water.

Gutters on farmstead buildings divert water away from barnyards, decreasing the amount of manure laden runoff.

Diversions are earthern ridges seeded with grass and shaped to prevent runoff from entering barnyards or areas susceptible to erosion.

Terraces are earthen ridges seeded with grass that follow hillside contours to break up long slopes. Runoff water is slowed down and diverted to a safe outlet, decreasing soil erosion.

Conservation tillages are plowing and planting practices in which a third or more of the residue (stalks, roots, etc.) from the prior year's crop is left on the field through spring planting. The residue protects the soil from the impact of rain, decreasing soil loss.

In nutrient management, fields receive only enough fertilizer and manure to meet a crop's nutrient needs. Soil test results and nutrient credits for legumes and manure already applied are used to calculate the proper amount. By not using excess fertilizer, the likelihood of nutrients reaching surface water and groundwater is decreased.

In crop rotation, the crops planted on a particular field from year to year are alternated. Planting crops such as hay can decrease the soil loss on a field that is too steep to continuously grow corn or soybeans.

Streambank protection involves stabilizing banks with vegetation and stones to reduce erosion and sedimentation in the stream bed.

Buffer strips of grass and shoreline plants along streambanks that filter runoff so that sediment and nutrients are removed before it enters the stream.

In areas undergoing urban development, soil erosion from construction sites is also a big concern for water quality. Among the construction site erosion control techniques you may see on the tours are:

Seeding and mulching of newly graded areas with fast-growing grasses stop soil erosion before it starts. Mulching prevents erosion while the grass seed is sprouting.

Stormwater detention ponds are temporary or permanent ponds built to hold runoff and allow pollutants time to settle out before the water enters streams or storm sewers.

Filter fabric fencing, if properly installed and maintained, traps sediment and slows runoff.

Stone weepers are piles of crushed stone, appropriately sized, that act as sediment filters and water detention structures, when placed in waterways.

Gravel drives keep vehicles from disturbing soil and tracking mud off-site.

Credits

This brochure grew out of an idea to run a one-day, 100 mile ride bike tour as part of a kickoff event for the Lake Mendota Watershed Project. Our goal was to design a tour that would show people the watershed and tell them about the land, the relationship between land use and water quality, and what can be done to make that a healthy relationship. To identify points of interest on the tour, solicitations were sent to people who know the watershed in different ways: geologists, teachers, naturalists, UW-Extension specialists, etc., asking them to tell us what places they would show people and why. We plotted all of these points of interest on a map and began drawing routes to connect them. We found we had a large number of points, and decided that designing several shorter tours might encourage more people to take them. We laid out a tour for each of the main streams draining into the lake, plus one for the lake itself. Each route was designed to leave the watershed at some point. No doubt there are places left out and stories untold and, over time, places will change: these rivers keep rolling. Written by Harry Read.

Those who contributed to this project include Mindy Habecker, Jan Harrison, Danielle Dresden, Suzanne Wade, Laurie Lambert, Jim Stephenson, Paul Gempler, Karen Etter Hale, Ken Wood, and Jon Dore'. Artwork and layout were prepared by Jill Bates-Warren and cartography by Dan Seidensticker. Printing was done by the UW Environmental Resources Center. Funding for this project was provided primarily from the Wisconsin Department of National Resources, Nonpoint Source Section.

This online version was designed and formatted by Scott Rose.

References

Dane County Water Quality Plan, Dane County Regional Planning Commission, 1975.

The Wetlands of Dane County, Barbara L. Bedford, Elizabeth H. Zimmerman and James H. Zimmerman, Dane County Regional Planning Commission, 1974.

Better Lawns and Gutters, Dane County Lakes and Watershed Commission, UW Nutrient and Pest Management Program, and Dane County Extension, 1990.

Conservation Choices, Your guide to 30 conservation and environmental farming practices. USDA, Soil Conservation Service.

Glacial Landscapes of Dane County, David Mickelson, Wisconsin Geological and Natural History Survey, 1983.

Geology and Ground-water Resources of Dane County, Wisconsin, Denzel R. Cline. Geological survey water supply paper 1779-U, Wisconsin Geological and Natural History Survey, 1965.

webmaster