Storm water is untreated runoff from rainfall and snowmelt.  It flows across impervious surfaces, through fields and over construction sites, crossing municipal boundaries and carrying contaminants to our lakes and streams.  These contaminants can include sediment, excess nutrients, heavy metals, oil, pesticides and bacteria.  Water pollution and contaminated storm water runoff degrade surface waters, making them unsafe for drinking, fishing, swimming, and other activities.  As authorized by the Clean Water Act and administered by the United States Environmental Protection Agency (EPA), the National Pollutant Discharge Elimination System (NPDES) permit program controls water pollution by regulating the discharge of pollutants into waters of the United States. In the State of Wisconsin, the Wisconsin Department of Natural Resources (DNR) administers the Wisconsin Pollutant Discharge Elimination System (WPDES) program in accordance with EPA regulations.  The Village of Mukwonago is a mandatory participant in the WPDES program. The purpose of the storm water permit is to encourage communities and residents to take an active role in preventing pollution from storm water runoff.  Potential sources of pollution include parking lot and street wash off, illegal dumping of chemicals into storm sewer system, improper pet waste cleanup, agricultural runoff, fertilizer and pesticide over application, failing septic systems and many other sources.  Since all storm water in Mukwonago ultimately ends up in our local lakes and rivers, the community as a whole has a responsibility to protect our pristine waters. The minimum requirements of the Village’s WPDES permit are summarized in the six control measures listed below.

  • Develop and implement a program to educate the Village’s residents on the impacts of storm water discharges into our local waterways, and the steps necessary to reduce storm water pollution.
  • Develop and implement a public participation program to engage the Village’s residents and assist in activities resulting in the reduction of storm water pollution.
  • Develop and implement a program prohibiting illicit connections or discharges (including dumping) to the storm water management system, create sewer maps, and offer public education on the hazards of illicit discharges.
  • Develop, implement, and enforce a program to reduce storm water pollution from construction activities.
  • Develop, implement, and enforce a program that addresses storm water runoff from new development and redevelopment projects, generally using structural and non structural best management practices (BMPs).
  • Develop and implement a program that considers pollution prevention and good housekeeping measures for maintenance activities, street runoff controls, storm sewer waste disposal, and flood control management projects.

The Village has joined Waukesha County in the development of a public information, education and participation program.  This partnership will allow the Village to cost effectively implement many of the permit requirements. The Village of Mukwonago is committed to protecting and enhancing our local waterways.  For more information or to see how you can help, please visit the following websites or contact the Village Hall.

Annual Reports
What are “impervious and pervious areas”?

Impervious areas are those that do not absorb rainwater.  Examples include the roof of a building, driveways, parking lots, paved playground areas, tennis courts or hard packed soil.  Pervious areas are those that absorb rainwater and primarily consist of lawns and other grassy surface areas.  While these areas do absorb rain water, pervious surface areas generate some runoff, primarily during heavy rain events.

Why should I be concerned about storm water runoff?

The most obvious effect of storm water runoff occurs during heavy rainstorms, when flooding and basement backups become a problem.  However, the pollution to local rivers, streams and lakes can be significant from even small amounts of runoff.  Storm water discharge from 1 square mile of road or parking lots can yield 20,000 gallons of residual oil per year.

Storm Water Ordinance and Permit Information


Ron Bittner
Public Works Director

(262) 363-6447
(262) 363-7197 Fax

Hours of Operation
Monday - Friday
7:00 am to 3:30 pm

630 East Veterans Way
Mukwonago, WI 53149