Key Agencies and Data Sources

Why this matters: Almost every water question about a specific Wisconsin parcel is answerable for free, before you make an offer. This is the list of who holds what, and what you would use each source for.

All URLs verified to resolve as of July 24, 2026. A handful block automated checking and were confirmed by domain; those are flagged.

State: Wisconsin DNR

DNR is the state water agency. It administers navigable waters (ch. 30), high capacity wells (281.34), water use registration and Great Lakes permits (281.343 to 281.348), drinking water (NR 809, NR 812), and contaminated site cleanup (ch. 292).

Resource	URL	Use it for
Water Use Program	https://dnr.wisconsin.gov/topic/WaterUse	Program landing page for registration, permits, reporting, and the Compact
Water Use Registration	https://dnr.wisconsin.gov/topic/WaterUse/registration.html	Confirm whether a property’s withdrawal must be registered, and how to transfer an existing registration at closing
Water Use Permitting	https://dnr.wisconsin.gov/topic/WaterUse/permits.html	Determine whether a Great Lakes basin withdrawal needs a general or individual permit
Water use data and maps	https://dnr.wisconsin.gov/topic/WaterUse/data.html	The single most useful page. Water Quantity Data Viewer, application search, high capacity well and surface water withdrawal search, annual water use reports
High Capacity Wells program	https://dnr.wisconsin.gov/topic/Wells/HighCap	Rules, groundwater protection areas, 2017 Act 10 transfer guidance
High capacity well application and instructions	https://dnr.wisconsin.gov/topic/Wells/HighCap/Apply.html	Read before assuming an existing approval can simply be transferred with the land
Central Sands Lakes Study	https://dnr.wisconsin.gov/topic/Wells/HighCap/CSLStudy.html	The definitive modeling on cumulative drawdown in the Central Sands
Wells program	https://dnr.wisconsin.gov/topic/Wells	NR 812 construction standards, setbacks, abandonment and sealing requirements
Well records search / groundwater data	https://dnr.wisconsin.gov/topic/Groundwater/Data.html	Pull the Well Construction Report (Well Driller’s Report) by Wisconsin Unique Well Number: depth, casing, geology logged during drilling, static water level, yield
Groundwater program	https://dnr.wisconsin.gov/topic/Groundwater	Groundwater quality standards, monitoring, groundwater flooding
Drinking Water program	https://dnr.wisconsin.gov/topic/DrinkingWater	Public water system test results, NR 809 standards, private well guidance
Waterway and Wetland Permits	https://dnr.wisconsin.gov/topic/Waterways	Navigability determinations, OHWM determinations, ch. 30 permits for piers, dredging, fill, and shoreline structures
Wetlands	https://dnr.wisconsin.gov/topic/Wetlands	State wetland program, delineation requirements, mitigation
Wetland mapping	https://dnr.wisconsin.gov/topic/Wetlands/mapping.html	Wisconsin Wetland Inventory. Screening tool, not a substitute for a field delineation
Surface Water program	https://dnr.wisconsin.gov/topic/SurfaceWater	Lake and stream data, impaired waters list, water condition viewer
Surface Water Data Viewer	https://dnrmaps.wi.gov/H5/?viewer=SWDV	Interactive map: navigable waters, wetlands, lake depth, impaired waters, trout stream classifications, watersheds
All DNR maps and apps	https://dnr.wisconsin.gov/maps/AppList	Index of every DNR interactive viewer, including the Well Driller Viewer
Shoreland Zoning program	https://dnr.wisconsin.gov/topic/ShorelandZoning	Statewide NR 115 standards. Note that counties administer, so this is background, not the operative rule
Shoreland Management Program standards summary	https://dnr.wisconsin.gov/topic/ShorelandZoning/Programs/program-management.html	Plain-language summary of setback, buffer, impervious surface, and nonconforming structure rules
BRRTS / Bureau for Remediation and Redevelopment Tracking System	https://dnr.wisconsin.gov/topic/Brownfields/BOTW.html	Search open and closed contaminated sites by address, municipality, or map. Run this on the parcel and everything within a half mile before you make an offer
PFAS program	https://dnr.wisconsin.gov/topic/PFAS	Standards, funding programs, site-specific pages for Marinette, La Crosse, and others
PFAS Interactive Data Viewer	https://dnr.wisconsin.gov/topic/PFAS/DataViewer	Known PFAS contamination locations, cleanup status, municipal drinking water results, fish and game consumption advisories, sampled waterbodies
Great Lakes Compact and Diversions	https://dnr.wisconsin.gov/topic/WaterUse/Compact.html	Wisconsin’s authoritative diversion table and Compact implementation
Waukesha diversion file	https://dnr.wisconsin.gov/topic/WaterUse/Waukesha.html	Every approval document, annual report, and Root River monitoring submittal. A model of what a full diversion record looks like

Water Use Program phone: 608-266-2299.

State: other agencies

Agency / resource	URL	Use it for
WGNHS (Wisconsin Geological and Natural History Survey)	https://wgnhs.wisc.edu/	The state geological survey, housed at UW-Madison. Depth to bedrock, aquifer characteristics, karst mapping
WGNHS maps and data	https://wgnhs.wisc.edu/maps-data/	County geologic maps, well construction and geologic logs, bedrock and surficial geology
WGNHS groundwater resources	https://wgnhs.wisc.edu/water-environment/groundwater/	Aquifer descriptions, groundwater flow, contamination susceptibility
DATCP (Dept. of Agriculture, Trade and Consumer Protection)	https://datcp.wi.gov/	Agricultural runoff, nutrient management plans, farmland preservation
DATCP nutrient management	https://datcp.wi.gov/Pages/Programs_Services/NutrientManagement.aspx	Whether nearby farms operate under a nutrient management plan and what it requires
PSC of Wisconsin electronic records	https://apps.psc.wi.gov/vs2015/ERF_search/content/default.aspx	Utility dockets. Search here for data center power requests, transmission line proposals, and water utility rate cases
DOA Wisconsin Land Information Program	https://doa.wi.gov/Pages/LocalGovtsGrants/WLIP.aspx	Program hub for county land records modernization
County contacts and websites (all 72 counties)	https://doa.wi.gov/DIR/County_Contacts.pdf	Direct links to every county’s GIS portal, LiDAR download, real property lister, and Register of Deeds. Start here rather than searching for a county by name
Wisconsin Statewide Parcel Map Initiative	https://www.sco.wisc.edu/parcels/data/	Statewide parcel geodatabase from the State Cartographer’s Office. Useful for looking at a neighborhood, not just one lot
UW Soil and Forage Analysis Lab	https://uwlab.soils.wisc.edu/	State-affiliated lab for soil and water testing

GeoData@Wisconsin (https://geodata.wisc.edu/) is the state geospatial data portal. It blocks automated requests, so it was not machine-verified, but it resolves normally in a browser.

Federal

Resource	URL	Use it for
USGS National Water Information System	https://waterdata.usgs.gov/nwis	Stream gage records and groundwater monitoring well records. Pull the nearest gage and look at 30 years of flow, not last summer
USGS Upper Midwest Water Science Center	https://www.usgs.gov/centers/upper-midwest-water-science-center	The USGS office covering Wisconsin. Study reports, modeling, partnership work with DNR on the Central Sands. Blocks automated requests; resolves in a browser
NRCS Web Soil Survey	https://websoilsurvey.nrcs.usda.gov/app/	Soil type, drainage class, depth to water table, septic suitability, hydric soil ratings. Free, and it answers the “will a mound system work here” question before you pay an engineer
FEMA Flood Map Service Center	https://msc.fema.gov/portal/home	Official FEMA Flood Insurance Rate Maps by address. Determines whether flood insurance is required and what the base flood elevation is. Blocks automated requests; resolves in a browser
USACE Detroit District, Great Lakes water levels	Search “USACE Detroit District Great Lakes water levels”	Monthly water level bulletins and the 6-month forecast. The site’s certificate configuration blocks scripted checks; use the browser

Regional and interstate

Resource	URL	Use it for
Great Lakes-St. Lawrence River Basin Water Resources Council	https://www.glslcompactcouncil.org/	The Compact Council. Diversion applications, final decisions, procedures, and the Compact text itself
IJC Protection of the Waters of the Great Lakes	https://www.ijc.org/en/pwgl	The decadal binational review of diversions and uses. The 2025 report is the current one
Alliance for the Great Lakes	https://greatlakes.org/	Advocacy organization. Their August 2025 water use report is the best available treatment of data center demand in the basin
Wisconsin Coastal Resilience	https://wicoastalresilience.org/	Monthly Lake Michigan water level updates, bluff and erosion resources, coastal hazard mapping. The most useful single source if you are buying lakefront
Midwest Environmental Advocates	https://midwestadvocates.org/	Nonprofit environmental law firm. Their litigation dockets are where data center water and power figures have surfaced

County and local, the ones that actually decide things

There is no statewide portal for any of these. Use the DOA county contacts PDF to find the right county office.

Office	Use it for
County Register of Deeds	The deed chain. Easements, restrictive covenants, prior riparian conveyances, plats of survey, mineral reservations. Read the whole chain, not just the current deed. This is where a pre-1994 riparian easement or an access easement to a back lot will show up
County zoning / land use department	The operative shoreland ordinance and its current text. Setback, buffer, impervious surface, and lot size as actually adopted in that county. Ask specifically whether the ordinance has been conformed to 2015 Wis. Act 55
County shoreland zoning administrator	Get the buildable envelope in writing before you make an offer. Whether an existing structure is legal nonconforming. Whether setback averaging applies
County GIS / land information office	Parcel boundaries, aerial imagery (often back to the 1930s), LiDAR-derived contours, zoning overlays, floodplain layers
County land and water conservation department	Local well testing programs and results by township. Nutrient management plan filings. Manure spreading restrictions
County health department	Well testing programs, sanitary permit records, septic system (POWTS) records for the parcel
Town or village clerk	Local ordinances the county does not administer: keyhole and funneling ordinances, boat and pier restrictions, local water utility agreements

Trade and professional

Resource	Notes
Wisconsin Water Well Association	The state trade association for well drillers and pump installers. Useful for finding a licensed driller for a pre-purchase well inspection or a yield test. `[UNVERIFIED]` current official URL. wiwwa.com exists but blocks automated checking. Verify in a browser or call DNR’s private water program for a referral
State-certified drinking water labs	DNR maintains the certified lab list. Use a certified lab for any test result you intend to rely on in a purchase contract
Licensed hydrogeologist	For any parcel where the well is the water supply and the geology is karst, fractured bedrock, or Central Sands, this is the specialist to hire. A driller tells you what is there. A hydrogeologist tells you whether it will still be there in 20 years

The 10 minute pre-offer screen

Run these 7 in order on any Wisconsin parcel. All free.

Step	Source	Question answered
1	County GIS + DOA county contacts	Where exactly is the parcel, and what is the zoning
2	DNR Surface Water Data Viewer	Is there a navigable water on or touching it, and is it a trout stream or an outstanding resource water
3	DNR Wetland Inventory	Is any of it mapped wetland
4	FEMA Flood Map Service Center	Is any of it in a mapped flood zone
5	NRCS Web Soil Survey	Will a septic system work, and how deep is the water table
6	DNR BRRTS + PFAS Data Viewer	Are there contaminated sites on or near it
7	DNR Water Quantity Data Viewer	How many high capacity wells are within 5 miles, and are they increasing

If all 7 come back clean, then pay for the OHWM determination, the well test, and the attorney. If any of them come back dirty, you have saved yourself the money.