Well Water Notebook
Information only, not medical advice. We never say whether your water is safe to drink. Ask a state-certified lab or your local health department. Disclaimer

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Who regulates big groundwater pumpers?

Short answer: your state does, and sometimes a regional water district or river basin commission. There's no federal permit for pumping groundwater. Most states set a size threshold (often about 100,000 gallons a day), and wells above it need a permit, an approval or at least a registration. A household well is far below that. If a data center, factory, farm, golf course or water utility plans a big new well near you, these are the offices and databases to check, with examples from 13 states.

This is general information, not legal advice. Water law differs a lot from state to state, thresholds and deadlines change, and some states have little or no permitting outside designated areas. Confirm the current rules with your state agency before you rely on a deadline. Nothing here can tell you whether any well's water is safe to drink.

Why it matters to a well owner

Pumping lowers the water level around the pumping well. USGS calls this a "cone of depression." When those cones overlap, wells interfere with each other, and a heavily pumped well can lower water in nearby wells.12 Whether a specific project affects you depends on the aquifer, the pumping rate, recharge and other users. In some aquifers the effect on neighbors is small or can't be measured.3

Permit and registration files are often the only public place that lists a project's planned wells, pumping rates and aquifer. Reading them early gives you time to comment, ask for monitoring and record a baseline for your own well.

Who regulates what

State examples: thresholds and where to look

Thresholds are as stated on each agency's page or rule when we checked. "Registration" usually means the owner reports the well and its use; it isn't always a pre-approval.

State Who What triggers review Where the public can look
Arizona Dept. of Water Resources (ADWR) Rules depend on location. Inside an Active Management Area, new wells for Pima County's "Project Blue" data center had to be tied to existing groundwater rights, with yearly use reports.6 ADWR's Wells55 well record search, by parcel or map.7
Florida Regional water management districts Thresholds differ by district. In the Southwest Florida district, an individual water use permit is needed at 100,000 gallons a day (annual average) or more, 1,000,000 gallons a day of capacity, or a well 6 inches or wider at the surface.9 Each district's ePermitting search, for example Southwest Florida WMD.8
Georgia Environmental Protection Division (EPD) A permit to withdraw more than 100,000 gallons a day of groundwater.10 EPD gives notice of its proposed action on permits, and permits can be contested.11
Indiana Dept. of Natural Resources (DNR) Facilities able to pump more than 100,000 gallons a day must register within three months after completion and report use yearly. Construction dewatering must be reported too.12 Ask DNR's Division of Water. Small-well owners can file a complaint if nearby high-capacity pumping makes their well fail.13
Michigan EGLE Registration before operating any withdrawal with capacity of 100,000 gallons a day (70 gallons per minute) or more, screened with the online Water Withdrawal Assessment Tool for effects on nearby streams and rivers. A permit above 2,000,000 gallons a day, or above 1,000,000 in low-water-availability zones.14 Ask EGLE's Water Use Program (517-599-3792).14
Minnesota DNR A water use permit to withdraw more than 10,000 gallons a day or 1 million gallons a year. Water bought from a city system is exempt.15 Your DNR area hydrologist. Data center pre-application talks are nonpublic.16
North Carolina DEQ Division of Water Resources In 15 coastal plain counties (the Central Coastal Plain Capacity Use Area), a permit for groundwater use over 100,000 gallons a day, and registration and yearly reporting above 10,000 gallons a day.18 DEQ's capacity use area pages and staff contacts.18
Ohio ODNR Division of Water Resources Facilities able to withdraw more than 100,000 gallons a day must register within three months after completion and report yearly.19 Ask ODNR. Because registration comes after construction, it won't warn you in advance.19
Pennsylvania (Susquehanna basin) Susquehanna River Basin Commission (SRBC) Withdrawals of 100,000 gallons a day or more (30-day average), and consumptive use of 20,000 gallons a day or more.20 SRBC posts pending applications with comment deadlines and runs the Water Application and Approval Viewer.21
Texas Local groundwater conservation districts Groundwater generally follows the "rule of capture," but districts permit most new wells and can set spacing and production limits.2223 Each district decides by rule which applications get a hearing.24 Find your district through the Texas Water Development Board.25
Utah Division of Water Rights Water right applications. New large data centers must also report water use before construction and every year.26 Applications are advertised in a local newspaper once a week for two weeks. Protests are due within 20 days after advertising ends ($15 fee).27
Virginia DEQ In the Eastern Virginia and Eastern Shore Groundwater Management Areas, a permit for withdrawals of 300,000 gallons a month or more. Temporary construction dewatering under 24 months is excluded.28 Draft permits are published in a local newspaper, local governments are notified, and there's at least a 30-day comment period with the option to request a hearing.29
Wisconsin DNR Approval before building or operating a high-capacity well system (capacity over 100,000 gallons a day). Home wells are excluded.30 DNR's public well application search and high-capacity withdrawal search.30

Not listed? Search your state's name with "water use permit," "high capacity well" or "water withdrawal registration," or ask your county health department or extension office which agency handles large wells. Our state pages list each state's well program.

How to find out what a specific project plans

  1. Learn the water source. Ask at the county or city planning hearing whether the project will buy water from a utility or drill its own wells, and its expected average and peak daily use. NGWA suggests communities ask for water demand projections, a hydrogeologic assessment, a monitoring plan and a drought contingency plan.3
  2. Check the utility, too. About 97% of data centers' on-site water came from public water systems in 2025, according to the Congressional Research Service.4 If that utility pumps groundwater, a big new customer can still raise demand on the aquifer.3 Utility boards usually approve service agreements, though some agreements limit what's disclosed.4
  3. Search the state database for the applicant's name, the parcel or the township. Projects often go by code names, such as "Project Blue" in Pima County, Arizona, so search the address and parcel too.6 Minnesota's DNR has said local officials sometimes hear only about "an industrial water user."5
  4. Watch public notices. Depending on the state, that's the legal notices in the local paper, the agency's public-notice page, or the basin commission's agenda.292721
  5. Comment or protest on time. Deadlines are short (20 days in Utah, at least 30 days in Virginia).2729 Stick to specifics: distance to your well, your well's depth, any past water-level problems, and a request for monitoring wells and a plan for what happens if nearby wells are affected.3
  6. Document your own well first. A dated water level, a lab test and photos give you something to compare against later. See how to document your well before nearby construction or heavy pumping.

If your well changes after pumping starts

What this page can't tell you

Frequently asked questions

Does a household well need one of these permits? Usually not. Thresholds are typically in the tens or hundreds of thousands of gallons a day, and Wisconsin explicitly excludes residential wells from its high-capacity definition.3015 Your state may still require a construction permit or well log for a new home well. See who regulates private wells.

What's 100,000 gallons a day in pump terms? Michigan treats it as a pump capacity of 70 gallons per minute.14

A data center says it will use city water. Is there a groundwater permit to look for? Maybe not. Minnesota, for example, exempts water bought from a city system from a separate state permit.15 Look at the utility's own supply and any service agreement instead.4

Can construction dewatering lower my well even without a permanent well? Pumping groundwater out of excavations can lower nearby water levels, which is why Indiana investigated wells near large construction sites in 2025.31 Some states regulate dewatering separately: Virginia excludes temporary dewatering under 24 months from its groundwater permits, while Indiana requires it to be reported.2812

Where can I see who's pumping near me now? Wisconsin's withdrawal search, Arizona's well registry and SRBC's viewer are public.30721 Elsewhere, ask the state agency in the table.

  1. USGS, "The mutual interference of artesian wells on Long Island, New York." https://www.usgs.gov/publications/mutual-interference-artesian-wells-long-island-new-york ↩

  2. USGS Water Science School, "Why do water levels in wells rise and fall?" https://www.usgs.gov/water-science-school/science/water-qa-why-do-water-levels-wells-rise-and-fall ↩

  3. National Ground Water Association, "FAQ Sheet: Data Centers and Groundwater: What You Need to Know for Your Community" (2026) (PDF). https://www.ngwa.org/docs/default-source/default-document-library/faq-data-centers-and-gw_final.pdf ↩↩↩↩↩↩

  4. Congressional Research Service, "Data Centers and Water: Frequently Asked Questions" (R49057, July 31, 2026). https://www.congress.gov/crs-product/R49057 ↩↩↩↩

  5. Kirsti Marohn, "Water-guzzling data centers spark worries for Minnesota's groundwater," MPR News, Feb. 11, 2025. https://www.mprnews.org/story/2025/02/11/water-guzzling-data-centers-spark-worries-for-minnesotas-groundwater ↩

  6. Katya Mendoza, "Arizona water officials approve wells tied to Project Blue data center," AZPM News, 2026. https://news.azpm.org/s/103423-arizona-water-officials-approve-wells-tied-to-project-blue-data-center/ ↩↩

  7. Arizona Department of Water Resources, "Well Record Search." https://www.azwater.gov/permitting-wells/well-record-search ↩↩

  8. Southwest Florida Water Management District, "Water Use Permit." https://www.swfwmd.state.fl.us/business/epermitting/water-use-permit ↩↩

  9. Fla. Admin. Code R. 40D-2.041, "Permits Required" (via Cornell LII). https://www.law.cornell.edu/regulations/florida/Fla-Admin-Code-Ann-R-40D-2-041 ↩↩

  10. Georgia Rules and Regulations 391-3-2-.03, "Permit Required" (groundwater use). https://rules.sos.ga.gov/gac/391-3-2 ↩

  11. Official Code of Georgia § 12-5-96 (via Justia). https://law.justia.com/codes/georgia/title-12/chapter-5/article-3/part-2/section-12-5-96/ ↩

  12. Indiana DNR Division of Water, "Significant Water Withdrawal Facility Registration." https://www.in.gov/dnr/water/water-availability-use-rights/significant-water-withdrawal-facility-registration/ ↩↩

  13. Indiana DNR Division of Water, "Water Rights: Emergency Regulation" (Indiana Code 14-25-4). https://www.in.gov/dnr/water/water-availability-use-rights/water-rights-emergency-regulation/ ↩↩

  14. Michigan EGLE, "Part 327 water withdrawal permits and registration." https://www.michigan.gov/egle/about/organization/geologic-resources-management/groundwater/water-use/permits ↩↩↩

  15. Minnesota DNR, "Water use permits." https://www.dnr.state.mn.us/waters/watermgmt_section/appropriations/permits.html ↩↩↩

  16. Minnesota Statutes § 103G.265, subd. 5, "Preapplication evaluation of certain water appropriation projects" (2025). https://www.revisor.mn.gov/statutes/2025/cite/103G.265/subd/103G.265.5 ↩

  17. Minnesota DNR, "Well interference process" fact sheet and "Well interference resolution process." https://files.dnr.state.mn.us/natural_resources/climate/drought/well-interference-fact-sheet.pdf, https://www.dnr.state.mn.us/waters/watermgmt_section/appropriations/interference.html ↩↩↩

  18. NC DEQ Division of Water Resources, "Central Coastal Plain Capacity Use Area (CCPCUA) Water Withdrawal Permit." https://www.deq.nc.gov/about/divisions/water-resources/groundwater-resources/central-coastal-plain-capacity-use-area-ccpcua-water-withdrawal-permit ↩↩↩

  19. Ohio Revised Code § 1521.16, "Registering facilities capable of withdrawing more than 100,000 gallons a day." https://codes.ohio.gov/ohio-revised-code/section-1521.16 ↩↩

  20. Susquehanna River Basin Commission, "Regulating Water Uses in the Susquehanna River Basin" (fact sheet, August 2024) (PDF). https://www.srbc.gov/our-work/fact-sheets/docs/regulating-water-uses-in-srb.pdf ↩↩

  21. Susquehanna River Basin Commission, "Regulatory Public Comment." https://www.srbc.gov/regulatory/public-comment/ ↩↩↩

  22. Texas A&M AgriLife Extension, "Basics of Texas Water Law." https://mytexas.ag.tamu.edu/publications/basics-of-texas-water-law/ ↩↩

  23. "Questions About Groundwater Conservation Districts in Texas" (PDF, hosted by the Railroad Commission of Texas). https://www.rrc.texas.gov/media/p11mfair/groundwater-cleanup-questions-dist.pdf ↩

  24. Texas Water Code § 36.114, "Permit; Permit Amendment; Application and Hearing" (via Texas.Public.Law). https://texas.public.law/statutes/tex._water_code_section_36.114 ↩

  25. Texas Water Development Board, "Groundwater Conservation Districts." https://www.twdb.texas.gov/groundwater/conservation_districts/ ↩↩

  26. Utah Division of Water Rights, "Large Data Center Water Use Reporting." https://waterrights.utah.gov/data-centers/ ↩

  27. Utah Division of Water Rights, "Application Process Q&A" (2026) (PDF). https://waterrights.utah.gov/wrinfo/Brochures/Application-Process-2026.pdf ↩↩↩

  28. Virginia DEQ, "Ground Water" (withdrawal permitting). https://www.deq.virginia.gov/water/water-withdrawal/ground-water ↩↩↩

  29. 9VAC25-610-250, "Public notice of permit or special exception action and public comment period." https://law.lis.virginia.gov/admincode/title9/agency25/chapter610/section250/ ↩↩↩

  30. Wisconsin DNR, "High capacity wells." https://dnr.wisconsin.gov/topic/Wells/HighCap ↩↩↩↩

  31. Marek Mazurek, "State investigates groundwater issues near Amazon, GM projects," Inside INdiana Business / Indianapolis Business Journal, June 6, 2025. https://www.insideindianabusiness.com/articles/state-investigates-groundwater-issues-near-amazon-gm-projects-in-st-joseph-county ↩

  32. U.S. EPA, "Protect Your Home's Water." https://www.epa.gov/privatewells/protect-your-homes-water ↩