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Water overview

Clean water is vital for public health, a healthy environment and a strong economy. The Wisconsin Department of Natural Resources along with the U.S. Environmental Protection Agency, Army Corps of Engineers, counties and local municipalities all play a role in regulating water use, discharge and other activities that impact water. These efforts help protect the quality and quantity of this valuable resource for all the citizens of Wisconsin for a wide variety of uses. Many small businesses have processes or activities that can impact water. Below is a quick summary of key water regulations that could affect your business. There is also a short summary of compliance resources available on the compliance page.

Storm water

Storm water regulations control runoff from locations like parking lots, construction sites and industrial properties where rain or snowmelt can pick up contaminants and run into bodies of water. If your business stores materials outdoors where they may expose storm water to contaminants or you will be doing construction, you may be considered a point source of pollution and a DNR storm water permit may be needed. You may need to create a plan for controlling runoff and install best management practices to reduce storm water pollution. Any industrial facility with no exposed materials can apply for no exposure certification and a permit will not be needed. Learn more about the No Exposure Certification (SB-020) and which industries may need permits.


Industrial operations that discharge wastewater to a body of water or to a storm sewer are regulated through the Wisconsin Pollution Discharge Elimination System (WPDES) permit program. If you are treating your water prior to discharge, plans for the treatment system must be approved by the DNR prior to construction. Permit requirements depend on whether your business is considered a major or minor as well as a complex or noncomplex discharger. WPDES permits also apply to the land application of wastewater sludge.

If your business is discharging your wastewater to a municipal sewage treatment plant instead of directly to a water body, municipal ordinances may apply. Discharges are negotiated with the publicly owned treatment works (POTW) and may require controls or pre-treatment.

Small public drinking water systems

You are operating a public drinking water system if your business provides water to your customers or employees from somewhere other than a municipal system, and:

  • you serve an average of 25 or more individuals for at least 60 days of the year, or
  • you have 15 or more service connections.

The DNR approval of your water system plan and capacity is required prior to beginning well construction, and construction must be done by a licensed professional. Many systems are also required to have a certified operator to operate the system. All public water systems have to periodically sample their well water and report their finding to the DNR, and additional requirements apply if contaminants are found.

Water use (high capacity wells and withdrawals from the Great Lakes Basin)

If your public water system will have a pump capacity of 70 gallons per minute or more, it is considered a high capacity well system. The 70 gallons per minute threshold applies to all wells on the property combined, not each individual well. You will have to submit a high capacity well application and also report your annual withdrawal to the DNR. Requirements for these systems will be different from those with lower pumping capacity.

In addition, if you plan to withdraw an average of 100,000 gallons or more of water per day from groundwater or surface water over a 30-day period and you are located within the Great Lakes Basin, a water use permit will be needed.

Wetland disturbance or shoreline development

The DNR regulates the protection of wetlands and requires you to avoid filling wetlands whenever possible. If you will be excavating, grading, filling, removing or disturbing soil in a low area or wetland, you will need to get a permit which will require demonstrating that the proposed wetland impact cannot be avoided or reduced. You will also have to show that the project will not significantly harm the wetland's functions and values. General permits are available for some activities while others will require individual permits. A pre-application meeting with the DNR is required for individual permits to help you work through the requirements.

The Army Corps of Engineers, local counties, and municipalities also regulate wetlands. You will want to contact them early to learn about how their requirements will influence your project.

Not sure if your property or a property you are thinking of purchasing contains wetlands? First, you will want to walk the property to check for signs of wetlands. The DNR also has wetland inventory and soils maps to help you make a determination. However, these maps are just a guide. Only a professional wetland delineator can verify whether or not wetlands are present.

The DNR also regulates impacts to navigable waterways. Activities such as placing materials in a waterway, dredging, grading, constructing intake or outfall structures; and building or repairing boathouses, boat ramps, boat shelters, piers, docks, or wharves or controlling aquatic plants may require permits from the DNR, the Army Corps of Engineers, your county, or other local zoning authority. Other regulations that may influence your project include setbacks for structures, minimum lot sizes, restrictions on cutting vegetation, installing a septic system or well or building a walkway or stairs to the water. Contact your local zoning administrator for help determining which regulations apply.


All farms in Wisconsin have performance standards and prohibitions that they must comply with to control runoff from cropland and livestock. Nutrient management plans and manure control help minimize the likelihood of pollutants entering waterways. Large farms with 1,000 or more animal units, also known as Concentrated Animal Feeding Operations (CAFOs), have additional requirements including those pertaining to waste storage and manure spreading and will also need a Wisconsin Pollutant Discharge Elimination System (WPDES) permit.

Private wells

If you are constructing a private well on your property, you are required to obtain a notification number from the DNR prior to construction and a well construction report must be submitted afterwards. Your well must be built following the state private well code, which contains requirements such as criteria for well location and setback from contaminant sources. For most construction, only licensed well drillers and pump installers may perform the tasks. Check with your county to see if they have an ordinance requiring a well permit. If you operate a well or wells on your property with a combined capability of producing 70 or more gallons of water per minute, your water system is considered a high capacity system and additional regulations apply.

Once your well is constructed, protection and maintenance is your responsibility. The DNR recommends that you test for bacteriological contamination on a yearly basis as well as any time you notice a change in your water.

Additional resources