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Issues related to water when purchasing a property

The information provided below is intended to help individuals or businesses looking to purchase property by providing an overview of DNR programs and/or regulations related to water. Regardless of whether a property contains or is adjacent to a body of water, water issues can have a big impact on how a property is used or developed.

Drinking water

How do I know if there is a well on the property?

It is important to know if a property you are thinking about purchasing has any wells, whether they are active or inactive. Wells may be used for drinking water or irrigation, so you may not see a connection to the building pipes. The owner or realtor should be able to show you where an active well is. There are a few ways to investigate if there is an inactive well on a property:

  • Take a walk. If there is a 4-6 inch diameter metal pipe sticking up out of the ground (that isn't attached to a septic system), concrete curbing with a manhole or lid over it or holes in the ground lined with stone or concrete, you may have found a well. Be sure to check outbuildings or boxes covering pipes.
  • Look in the basement. Look for phantom pipes coming from the wall that are not attached to a pressure tank or other water supply system or a pipe sticking out of the floor in a side room.
  • Search the Wisconsin DNR Well Construction Information System for well reports.
  • Hire an inspector. A licensed well driller or pump installer can inspect the property and let you know about any active or unused wells.

Should I have a water system inspection done before purchasing a property?

Water system inspections are not required for property transactions. However, the buyer may choose to have an inspection conducted in order to learn about the quality of the water and condition of the well. An inspection can also help locate any unused wells on the property. If an inspection is performed, it must be conducted by a licensed well driller or pump installer to ensure the inspection is done properly. For more information on inspections, see the Property transfer well inspections page. Well construction reports and groundwater quality data can also be found on the DNR's Look up groundwater data page. If a well is part of a public water system, information on the quality of water can be found on the DNR's Public water supply systems lookup page.

Is a well(s) part of a public drinking water system? If so, what are the obligations?

Many small businesses that provide their own water to employees and/or customers qualify as public drinking water systems. A public drinking water system is defined as "a system for the provision to the public of piped water for human consumption, if such a system has at least 15 service connections or regularly serves an average of at least 25 individuals daily at least 60 days out of the year". In this definition, "serving" water means that water is available, regardless of whether or not people commonly drink it. Examples of businesses that may be small public water systems include industrial facilities with 25 or more employees, mobile home parks, subdivisions, apartment buildings, condominium complexes, day cares, campgrounds, gas stations, motels, restaurants and taverns. If the water comes from a local municipality, the business is not a public water system.

If you operate a public water system, you have legal obligations to ensure safe drinking water. There are four types of public water systems: municipal community, other-than municipal community, non-transient non-community and transient non-community. Depending on the type of system you operate, you may be required to have a certified operator to manage the drinking water system, have capacity evaluation and plan review approvals, periodically test for contaminants, report sampling results to the DNR and inform the public of water quality and any contaminant exceedances. To determine what type of system you operate and explore potential requirements, visit the DNR's Small Business Environmental Assistance Program's Public drinking water system page. The Wisconsin Rural Water Association and DNR Drinking Water and Groundwater (DG) Staff can also provide technical assistance to public drinking water system owner and operators.

What needs to be done when constructing a new well? How much will it cost?

The requirements for well construction will vary depending on the geology of the area and whether it will be a private well or a public water system.

Constructing a well for a public water system requires the well to be properly located, constructed, installed and maintained. A licensed well driller or pump installer is required for construction and maintenance of public drinking water system wells. The DNR also has plan review and capacity development requirements to ensure proper system construction and maintenance.

If you are putting in a well for private use, you must obtain a Well Notification Number from the DNR before beginning construction and submit a Well Construction Report upon completion. The well usually must be constructed by a state licensed well driller or pump installer according to the State Private Well Code, which establishes requirements for the location of the well. Make sure to also check with the county. They may have ordinances on wells, including permit requirements.

The cost of a well will vary depending on geology, construction, and whether or not it includes pump installation and water testing. Consult with a Wisconsin licensed pump installer or well driller for more information.

What are my obligations as a private well owner? How do I bring a well into compliance?

Protection and maintenance of a private well is the responsibility of the property owner. Although not a requirement, the DNR recommends testing a well for bacteriological contamination every year. You should also test a well if you notice a change in your water. The Contamination page has a list of contaminants that are most commonly tested for in drinking water. The page also has information about what the contaminants are, how they get into the water and how they are measured. There are many different types of contaminants that may impact drinking water, and many are dependent on location and geology.

Consult with a Wisconsin licensed pump installer or well driller for help bringing a well into compliance. Pump installers and drillers will be able to identify the non-complying features of a well and to recommend a course of action. Some wells will not be able to be brought into compliance, and it may be necessary to fill and seal an old well and install a new one. Private well owners may qualify for a well compensation grant from the DNR to help with replacing, reconstructing or treating a chemically contaminated well. See the Well compensation grant program page for details.

For more information, visit Information for homeowners with private wells. Our drinking water staff are also available to assist you if you need further clarification.

How do the requirements differ for high capacity well systems?

If a well or system of wells have a combined capacity of 70 gallons per minute or more, the system is considered high capacity and will be subject to additional requirements beyond those for lower capacity systems. In a high capacity system, all wells on the property are considered high capacity, regardless of the size of individual wells. High capacity wells must be approved by the DNR prior to beginning construction or reconstruction of a well or prior to beginning operation after a property transaction, so be sure to plan ahead. More information can be found on the High capacity well information page.

How should I handle unused wells?

The owner of the property has an obligation to identify and properly fill and seal any wells that are not in use or those that cannot be brought into compliance with regulations. Unused wells pose a threat to groundwater by providing a direct path for contaminates into the ground. Wells that are no longer in use must be filled and sealed by a licensed well driller or pump installer within 90 days of when they are removed from service. Grant funding may be available to help with the cost. Contact the county Land and Conservation Department for technical or financial assistance. See the Well filling and sealing and Well abandonment grants pages for details.

Storm water

When do I need a storm water permit

Will you own or manage a site where rain or melting snow flows off building rooftops, streets, parking lots, construction sites or industrial storage yards? Are the developed areas covered by buildings and pavement that do not allow water to soak into the ground? If so, you may need a storm water permit.

The Wisconsin Pollutant Discharge Elimination System (WPDES) Storm Water Discharge Permit Program regulates the discharge of storm water in Wisconsin from three potential sources:

Contaminated storm water is a major contributor of water pollution in urban areas. Regulated storm water discharges are considered point sources, so owners or operators of these sources are required to receive a WPDES permit for the discharge. This permitting mechanism is designed to prevent storm water runoff from washing harmful pollutants into local surface waters. If you have questions about how storm water permits could affect your operation, see the Storm water runoff permits or Storm Water Runoff Regulations page or contact DNR’s Storm water staff.

Construction Sites

The WPDES Construction Site Storm Water Discharge Permit is designed to help decrease the amount of sediment that pollutes Wisconsin's waterways due to new land disturbance. A landowner of a construction project where one acre or more of land will be disturbed must obtain permit coverage. Permittees must develop a Storm Water Management Plan and an Erosion and Sediment Control Plan describing the best management practices that will be used on-site. The plans can be developed using the Storm Water Construction and Post-Construction Technical Standards provided by the DNR. A Construction Site Notice of Intent form and applicable fee must be submitted to the DNR at least 14 working days before construction begins. Best management practices described in the Storm Water Management Plan and Erosion and Sediment Control Plan must be implemented to help control erosion and prevent contamination of storm water. Weekly on-site inspections through the duration of the project and after storm water events are also required.

Industrial Sites

Storm water may come into contact with a wide variety of pollutants from outdoor exposure of materials and activities at industrial facilities. Most storm sewers do not connect to a wastewater treatment plant, so untreated runoff carries pollutants directly into lakes, rivers and streams.

Ch. NR 216, Wis. Adm. Code contains a list of industrial facilities that must obtain storm water discharge permit coverage. The determination of whether an industrial facility must obtain permit coverage is based both on the facility's Standard Industrial Classification (SIC) code and whether or not the facility has the potential to contaminate storm water.

Permitted facilities must develop a site-specific Storm Water Pollution Prevention Plan (SWPPP). The goal of this plan is to encourage source-area control through identification of storm water pollution prevention individual, site-specific best management practices (BMPs) and implementation schedules to decrease the amount of contaminated storm water runoff from a facility. Some industrial facilities may also be required to conduct annual chemical monitoring for pollutants in runoff from their sites.

If your facility will have no materials or waste stored outdoors that could contaminate storm water, you may qualify for no-exposure certification and be exempt from permitting requirements. Visit the Industrial storm water permit no-exposure facilities page if you think this might apply to your facility.

Municipal Separate Storm Sewer Systems (MS4s)

The MS4 permits require that municipalities develop a storm water management program that includes information and education of the public, illicit discharge detection and elimination, creation and enforcement of local ordinances to regulate erosion control and long-term storm water management, and implementation of pollution prevention at municipally-owned facilities. MS4 permits require implementation of best management practices for source-area control instead of numerical effluent limits.

In Wisconsin, MS4 permittees are also required to implement a reduction in total suspended solids (TSS) in runoff that enters waters of the state as compared to no controls. A municipality is required, under s. NR 216.07(6)(b), Wis. Adm. Code, to provide an assessment of the actions taken to comply with the TSS performance standards. The initial assessment must include a pollutant-loading analysis using a model such as SLAMM, P8 or equivalent methodology that is approved by the DNR.

To control TSS, storm water management control practices such as storm water infiltration basins, wet ponds, bioretention and other practices may need to be implemented. The DNR has provided Technical Standards to assist the MS4 with the design of best management practices.

Sediment removal from wet and dry detention ponds and infiltration basins may be subject to the requirements of ch. NR 528, Accumulated Sediment from Storm Water Management Ponds.

Financial assistance may be available to MS4s. See the Grants and loans – financial assistance page for details.


How do I find out if there are wetlands on a property?

Wetlands serve a variety of vital ecological functions. Therefore, activities that will impact them are regulated. It is important to know if wetlands are present on a property and how their presence might impact your plans for the land being purchased.

A wetland is defined as "an area where water is at, near, or above the land surface long enough to be capable of supporting aquatic or hydrophytic (water-loving) vegetation and which has soils indicative of wet conditions." Wetlands are not necessarily wet during all parts of the year, so the lack of water at a given time does not mean wetlands are not present. The DNR has tools to help property owners identify wetland areas or potential wetland areas and decide if they need to hire a professional to conduct wetland delineation on the property.

The first step in evaluating a property for wetlands is to review existing maps. The Surface Water Data Viewer contains the Wisconsin Wetland Inventory maps which are designed to help determine if wetlands are likely to be present on a site. The Map review page provides more information on using maps.

Because maps are just guides and may not show every feature or wetland on a property, it is important to walk the land to see if the map accurately matches up with what is found on the ground and have a professional verify if wetlands are present. For a checklist describing physical clues to look for, see our Physical Clues page.

The DNR's Wetland Identification Program consists of two services that help landowners evaluate whether a wetland is present on their property.

  • The Wetland Identification Service provides a written evaluation, based upon an on-site inspection, of whether a property contains wetlands. Up to 5 acres can be reviewed for a fee of $300 per acre. Requesters will receive a response in 60 days or less. The wetland identification service cannot be used as a substitute for official wetland delineation, and will only provide requestors with a presence/absence determination and an approximate wetland boundary location. Because the service will only provide approximate wetland boundary locations, it may not be suitable for all projects. Projects that have setback requirements or are located very near a wetland may not be good candidates for the service.
  • The Wetland Confirmation Service consists of a written statement, based upon an on-site inspection, of whether the DNR agrees with the wetland boundaries delineated by a consultant. A fee of $300 per 20 acres of land reviewed is associated with this service, and requesters will receive a response in 60 days or less. The goal of this service is to provide landowners and developers certainty that a project’s delineated wetland boundaries are accurate before project plans are finalized. Taking advantage of this service early in the planning phase will prevent unexpected wetland boundary concerns from delaying the approval of a project.

If you’re considering buying land, you may want to complete a wetland addendum with your offer to purchase. The addendum gives you more time to hire a professional to verify whether there is a wetland and allows you to re–negotiate or rescind your offer.

For more information, visit the Wetlands page.

I want to build a road or structure but there is a wetland on the site. What should I do?

The DNR, U.S. Army Corps of Engineers, counties and local municipalities all regulate wetland impacts. State regulations require avoidance of wetland impacts if possible. Permitting requirements exist for activities that cannot avoid affecting wetlands. Permits take time, so it's important to plan ahead and apply for permits early in your planning process.

Projects that impact wetlands below certain thresholds may qualify for a general DNR permit if the permittee can meet all the required criteria. For projects that do not qualify for a general permit, the property owner will need to work with the DNR to apply for an individual permit. DNR staff will help determine how to minimize impacts and if any compensatory mitigation will be necessary. In the application it is necessary to demonstrate that wetland impacts cannot be completely avoided, list the steps that have been taken to reduce wetland impacts, and demonstrate that the project will not have significant adverse impacts on wetland functions and values. See Wetland regulatory programs or the Wetland Disturbance pages for details. It may also be a good idea to include the Army Corps of Engineers, U.S. Department of Agriculture’s Natural Resources Conservation Service and the local zoning office in the meeting with the DNR.

Shoreland zoning

What types of activities are regulated on shoreland property?

There is a variety of regulations that protect waterways. Projects on waterfront properties are therefore subject to additional regulations that do not apply to non-waterfront properties. If you have a body of water on or near your property, make sure you are familiar with state and local requirements before beginning any project. Contact the local zoning office to find out what types of development are allowed, what types activities are affected by shoreland zoning regulations and what permits may be required.

Many common activities on waterfront properties are regulated. Some of these activities include:

  • Construction, expansion or repair of any structure (home, cottage, boathouse, shed, etc.);
  • Placement of a septic system or well;
  • Adding a pier, dock, steps to the water, boat ramp or shelter, wharves, buoys, pilings, swimming rafts, water ski platforms, etc.;
  • Adding riprap, sand, or pea gravel;
  • Controlling for aquatic plants;
  • Conducting any earth moving activities (dredging, grading, etc.);
  • Installing intake/outfall structures;
  • Constructing a pond;
  • Mowing, removing or changing vegetation; and
  • Creating erosion controls.

Local ordinances may regulate on-water activities such as allowable watercraft speeds and time of operation. There are slow-no-wake rules to be aware of as well.

Many activities will require a permit. Visit the Water permit applications page for applications or to apply online or check out the Waterway Protection Exemptions page if you think a project may be exempt. Existing permits for structures such as piers generally transfer with the land, so buyers generally will not have to get new permits unless they are making modifications to the structure.

It is also important to keep in mind that waterfront property can change over time. Water levels may fluctuate significantly and the flow of rivers can change, which may alter a property and the activities that can be done on the water body. It is also important to be aware of groundwater levels when planning to construct a basement or septic system.

Who do I talk to about shoreline development?

A good place to start is to contact the local zoning office for construction and zoning issues. Also contact regional DNR Waterway Protection staff. Some projects may even require checking with the regional U.S. Army Corps of Engineers office.

What does "navigable waterway" mean? How does this affect a property?

A navigable waterway is defined as a lake, river or stream that has a bottom (bed) and side (bank), and enough water to float any boat, skiff, or canoe of the shallowest draft on a reoccurring basis. A waterway that is designated as navigable is classified as a public waterway. Occasionally, barriers such as wood or plant debris may impede actual navigation, but waters are public even when multiple portages are required to get around obstructions. A waterway does not need to be regularly used for recreational or other general purposes, but is a public waterway based on its capacity to be navigable and public.

Whether or not you have a navigable waterway on your property will influence certain regulations and/or permits that may be needed for activities on the land. Some examples of activities where people need to understand if a public waterway exists on a property are:

  • Fishing and hunting access;
  • Site planning and development;
  • Irrigating farm fields and extracting water for livestock use; and
  • Home and land improvements (i.e. building a garage, boat shelter, or tool shed; landscaping; expanding or adding a driveway and installing shoreline erosion control).

For more information on permitting and planning for construction activities on or near navigable waterway see the Waterway Protection page.

How do I find information about a lake?

If you are thinking about purchasing property on or near a lake, you may want to learn more about the lake to make sure it will be a good fit for you and how you plan to use it. Lake maps, information about aquatic plants, water quality and lake protection initiatives can be found on the DNR's Lakes page.

Can I pump water from a lake or stream?

Only the riparian owner (owner of land bordering a lake, river or stream) has a right to use water for domestic purposes. No permit is required to pump water for non-commercial purposes such as to water the riparian owner’s lawn or private gardens.

Water taken must be a nominal (reasonable) amount and cannot be detrimental to public rights and resources. The department may also set a public rights stage or a minimum water level or flow to protect public rights and resources. The amount of water taken cannot impact those stages, levels or flows.

For more information, access the Withdrawals and Irrigation page.

How do I know if a property is in a floodplain?

A floodplain is land that has been or may be covered by floodwater during a regional flood. To find out if a property is in a floodplain, you will need to consult a Flood Insurance Rate Map (FIRM). FIRMs are maps of areas at risk to flooding, also known as floodplains or Special Flood Hazard Areas (SFHA). Newer FIRMs use aerial photos as the base layer making it easier to determine if a structure or property is within a mapped floodplain. FIRMs can be viewed on FEMA's Map Service Center or on the DNR's mapping page. You can also contact the local zoning office for information on floodplains in your area.

Development is regulated within floodplains by local ordinances. For more information, visit the Floodplain Management page.

I’m interested in a property that has a dam on it. What do I need to know?

Dam ownership carries significant legal responsibility. A dam owner must first be familiar with the legal obligation to maintain a dam in a safe and reasonable condition. State law requires that an owner has a permit to construct, repair and/or operate a dam. Additional state or federal regulations for operation may apply if the dam is located on a navigable stream. For more information, visit the Dam Safety page.

Is a pond private or public?

Remember to check with the DNR if you plan to construct or modify a pond. Under certain conditions, a DNR permit will be required. If you plan on constructing near a pond, contact the local zoning office for construction and zoning requirements that may be relevant.

If a pond is a natural navigable waterbody, it is public. If the public can access the pond by the water from another public navigable waterbody, the public may use the pond even if it is an artificial pond. However, if a pond is completely surrounded by private property (not connected to a navigable waterbody), even if the pond is a public waterbody, no one can use the pond without the property owner's permission to cross the land.

Constructed ponds may be declared public if they will have an ongoing effect on public waters. If a pond was built between 1961 and 1988 and required a DNR permit, state law automatically made it public water. Other ponds installed after 1988 are private unless the DNR permit declares otherwise. See the Ponds page for more information.

Additional resources