Water Quality of Our Lakes
We work to protect the water quality of our lakes, beaches, and streams by:
- Monitoring and sampling area lakes, rivers, and streams to evaluate sources of potential pollution from discharge points and run-off to lakes and rivers.
- Responding to reports of improper discharges going into the storm sewer or lake that have an unusual color or odor, and unusual floating objects in the water.
- Testing water for indicators of environmental conditions of our water—ie. bacteria, toxins, and metals. During the summer months, Memorial Day to Labor Day, we test water at area beaches and post beach condition information. (See Beach Conditions page.)
- Regulating over 165 permitted sites for discharges of non-storm water to lakes Mendota, Monona, and Wabesa.
Causes of Water Pollution
When it rains, or the snow melts, stormwater that runs over driveways, parking lots, lawns streets, and farmland carries with it sediments and other contaminants that it picks up. These run-off pollutants can end up in the lakes through the stormwater system and other discharge points.
- Sediment and nutrients washed from farm land and construction areas cause lake and river waters to become murky and can gradually fill lakes and streambeds. It makes it hard for plants to grow and destroys aquatic habitats.
- Oil, grease, pesticides, herbicides, cleaners, and motor vehicle related toxic chemicals can make animals and humans sick and destroy aquatic life.
- Nutrients from lawn and garden fertilizers and leaves can lead to toxic algae blooms that can harm humans and animals, and lead to the death of fish and other aquatic life.
- Viruses, parasites and bacteria from waterfowl and pet waste, heavy rainfall, boat holding tank waste and failing septic systems may cause illness in people who swim in beach areas with high bacteria counts, and may also lead to possible contamination of drinking water.
- Road salt that has been applied to roads and sidewalks over the course of the winter ends up in our local lakes, streams, and aquifer-our drinking water source. Road salt is harmful to aquatic life and high sodium levels in drinking water can have harmful human health effects.
- The 2014 Environmental Health Report Card provides information on specific effects of phosphorus, chloride, and metals on our surface waters.
How to Protect our Lakes and the Environment
- Direct household wastewater to a sanitary sewer or approved and properly maintained septic system.
- Limit your use of pesticides, herbicides and fertilizers on lawns and gardens and follow label directions.
- Keep pet waste, debris, and trash (including leaves and grass clippings which provide nutrients for algae growth) out of gutters, sidewalks, streets, storm sewers and lakes.
- Wash your car in a location where the wastewater will soak into the ground and not run off into the gutter and storm sewer.
- Make sure your roof drains go to a grass or gravel area and do not go directly to the street, driveway, or paved area that drains to the storm sewer.
- If you see something going into the storm sewer or into a lake that has an unusual color or odor, or you see unusual floating objects in the water, report it to our Environmental Protection Unit by calling (608) 266-4821 or filling out an online report (below).
- Beaches Information, City of Madison Parks Division
- Blue-Green Algae Information, WI Department of Health Services
- Blue-Green Algae FAQ, WI Department of Natural Resources
- Clean Lakes Alliance website
- Dane County Lakes and Watershed Commission
- Friends of Lake Wingra website
- Madison and Dane County Water Quality Report Card - 2014
- Recreational water illness, Centers for Disease Control and Prevention
- Stormwater Runoff fact sheet
- Water Quality in Dane County: Overview, Current Challenges, and Recommendations, July 2017
- Wisconsin Beach Health, Wisconsin Beach Health program
- Wisconsin Beaches, WI Department of Natural Resources