Groundwater: the 4 doctrines and the regulatory hole

Why this matters: Groundwater is where the arbitrage is, where the depletion is, and where your Wisconsin well risk is. Surface water law is mature and contested. Groundwater law in most states is 40 years behind the hydrology.

The physical facts law spent a century ignoring

An aquiferaquiferUnderground rock or sand with water in the spaces between the grains. It is not an underground lake. Water seeps through it slowly, often only feet per year. isn’t an underground lake. It’s saturated sediment or fractured rock, and water moves through it slowly, typically feet per day or feet per year.

Three consequences that matter legally:

Pumping is a shared drawdowndrawdownHow far the water level drops while a pump is running.. A well creates a cone of depressioncone of depressionThe funnel-shaped dip in the water table around a pumping well. When your neighbor's funnel overlaps yours, your wells are competing for the same water. around it. Your neighbor’s cone and yours overlap. Nobody’s pumping is isolated.

Groundwater and surface water are the same water. Streams in humid regions are mostly baseflowbaseflowThe part of a river that is really groundwater seeping in at the surface. It is why pumping wells can dry up a stream., meaning groundwater discharging at the surface. Pump the aquiferaquiferUnderground rock or sand with water in the spaces between the grains. It is not an underground lake. Water seeps through it slowly, often only feet per year. and you capture water that would have become streamflow. This is called stream depletionstream depletionThe drop in a river caused by nearby groundwater pumping. The effect often shows up years later, which makes it easy for everyone to ignore. and the effect is often delayed by years, which makes it politically easy to ignore.

Some aquifers don’t refill on human timescales. The Ogallala under the High Plains and the deep alluvial basins of Arizona hold water that accumulated over thousands of years. Pumping those is mining, not harvesting. When the water leaves, the sediment can compactcompactA binding agreement between states that Congress approves. Once approved it becomes federal law and overrides conflicting state rules. The Great Lakes Compact is one. permanently, destroying storage capacity forever. That’s land subsidencesubsidenceThe ground surface permanently sinking after too much groundwater is pumped out. It destroys the aquifer's ability to hold water again, so it cannot be undone., and parts of the San Joaquin Valley have dropped more than 25 feet.

Early courts said groundwater’s movements were “so secret, occult and concealed” that no rules could govern it. That line, from an 1861 Ohio case, is still quoted, and it did real damage.

The 4 doctrines

1. Absolute dominion (English rule / rule of capture)

Pump all you want from under your land, whatever the effect on your neighbor. No liability.

Origin: Acton v. Blundell (England, 1843). Adopted widely in 19th century America, abandoned by nearly every state since.

Texas is the major survivor. Sipriano v. Great Spring Waters of America (Tex. 1999) upheld the rule of captureabsolute dominionPump as much as you want from under your own land, even if it drains your neighbor's well, with no liability. Nearly every state abandoned this. Texas largely kept it. even as the court called it inadequate, deferring to the legislature. Texas softened it with groundwater conservation districts, but the baseline is still capture, and Edwards Aquifer Authority v. Day (2012) held that landowners own groundwater in place as property, so district pumping limits can be a taking.

The economics are exactly what you’d predict. It’s a commons with a pumping race, and the winner is whoever has the deepest well and the biggest pump.

2. Reasonable use (American rule)

You can pump for any beneficial purpose on the overlying land, but you can’t waste it or transport it off the tract if doing so harms neighbors.

This is Wisconsin’s rule, adopted in State v. Michels Pipeline Construction (1974), which abandoned absolute dominionabsolute dominionPump as much as you want from under your own land, even if it drains your neighbor's well, with no liability. Nearly every state abandoned this. Texas largely kept it. and adopted the Restatement (Second) of Torts section 858 approach.

Important limitation: reasonable usereasonable useYou can use the water however you like until it unreasonably harms someone else's use. This is Wisconsin's groundwater rule. The catch: it is enforced by a lawsuit after the harm, not by a permit beforehand. is a tort standard, enforced after the fact by a lawsuit. It doesn’t stop a well from being drilled. It gives you a cause of action after your well goes dry, and you’ll pay for the hydrogeology expert to prove causation.

3. Correlative rights

All owners over a common aquifer share it proportionally, usually by acreage, and in shortage everyone cuts back together.

California’s rule, from Katz v. Walkinshaw (1903). It’s the groundwater analogue of riparianismriparianThe eastern US rule, and Wisconsin's rule. If your land touches a lake or stream, you get reasonable use of that water, shared with everyone else whose land touches it. The rights come with the land and generally cannot be sold separately from it.. California layered a permitting regime on top in 2014 with SGMASGMACalifornia's Sustainable Groundwater Management Act, passed in 2014. It requires local agencies to bring pumping into balance by 2040, and it was the state's first real groundwater regulation., the Sustainable Groundwater Management Act, which required local agencies to reach sustainability by 2040 and was the state’s first real groundwater regulation. It took until 2014.

4. Prior appropriation for groundwater

Some western states apply first-in-time to wells: New Mexico, Colorado (for tributary groundwater), Idaho, Kansas, Nevada, Utah.

Colorado’s is the most sophisticated, requiring “augmentation plansaugmentation planA Colorado requirement where a newer well owner has to replace the water their pumping takes from the river, in the same place and at the same time.” where a junior well pumper must replace the stream depletionstream depletionThe drop in a river caused by nearby groundwater pumping. The effect often shows up years later, which makes it easy for everyone to ignore. their pumping causes, in the time and place it occurs. It’s expensive and it works.

Where the states actually land

Arizona is worth staring at: the same state uses 2 different regimes depending on which side of a line you’re on. Inside an Active Management AreaActive Management AreaAn Arizona zone where groundwater pumping is actually regulated: metered, reported, and capped. Outside these zones there historically were no limits at all., you need a grandfathered rightgrandfathered rightAn Arizona water right based on how much you were already pumping when regulation arrived, rather than a new permit you applied for. or a permit and you’re metered. Outside one, it’s reasonable usereasonable useYou can use the water however you like until it unreasonably harms someone else's use. This is Wisconsin's groundwater rule. The catch: it is enforced by a lawsuit after the harm, not by a permit beforehand. with no pumping cap and no meter. That single line is the whole Fondomonte story.

The exempt well problem

Every state exempts small wells from permitting. The threshold is where the risk concentrates.

Two things to notice.

Wisconsin’s 100,000 gpd is a capacity threshold, not actual use, and it aggregates all wells on a property. Someone can install several wells that individually look small and collectively cross the line, which is exactly why the aggregation language exists.

35 gpm is roughly 50,000 gallons per day if run continuously. Arizona’s new Ranegras rules catch a much smaller well than Wisconsin’s threshold does. A single Wisconsin high capacity irrigation well can legally pump more than 100 times what a household uses, and until Lake Beulah it wasn’t clear the DNR could even look at its effect on the lake next door.

The Wisconsin high capacity well fight, in brief

Worth knowing before you buy anything with a well.

• 2011: Lake Beulah Management District v. DNR, 2011 WI 54. The Wisconsin Supreme Court held the DNR has both authority and a duty, grounded in the public trust doctrinepublic trust doctrineThe state holds navigable waters and the land beneath them for everyone, and cannot sign that away. Wisconsin's version is written into the state constitution and is among the strongest in the country., to consider a proposed high capacity wellhigh capacity wellIn Wisconsin, a well (or all wells on 1 property combined) capable of pumping 100,000 gallons a day or more. These need DNR approval. An ordinary house well does not.’s impact on nearby navigablenavigable in factWisconsin's test for whether a waterway is public. Roughly: can a small recreational boat float on it on a regularly recurring basis. A lot of modest creeks qualify. waters.
• 2011, same year: the legislature passed Act 21, adding Wis. Stat. 227.10(2m), which bars agencies from imposing any requirement not “explicitly” authorized by statute or rule. Public trust doctrinepublic trust doctrineThe state holds navigable waters and the land beneath them for everyone, and cannot sign that away. Wisconsin's version is written into the state constitution and is among the strongest in the country. is common law, so it isn’t “explicit” anywhere.
• 2016: Attorney General Schimel issued an opinion that 227.10(2m) had stripped the DNR’s Lake Beulah authority. The DNR stopped considering environmental impacts and approved wells accordingly.
• 2021: Clean Wisconsin, Inc. v. DNR, 2021 WI 72. The court held 227.10(2m) did not strip that authority, because Wis. Stat. 281.12 grants the DNR “all authority necessary” to protect state waters, and that counts as explicit. Lake Beulah survives. A companion case, 2021 WI 71, upheld DNR conditions on CAFOCAFOA large industrial livestock operation. In Wisconsin water disputes it is usually the source of the nitrate and bacteria showing up in neighbors' wells. permits.

As of July 2026 that’s still the law. It’s a 4 to 2 decision resting on statutory interpretation, which means a legislature or a differently composed court could revisit it. Track it.

Detail and citations in ../03-wisconsin-great-lakes/01-wisconsin-water-law.md and ../01-cases/.

What to ask about any parcel’s groundwater

1. Which aquifer, at what depth, in what geology? (Sandstone, dolomite, sand and gravel, fractured crystalline. Each behaves differently.)
2. What’s the static water levelstatic water levelHow far down the water sits in a well when nothing is pumping. Tracking this over decades is the best single indicator of whether an aquifer is in trouble., and what’s the 20 year trend?
3. How many high capacity wellshigh capacity wellIn Wisconsin, a well (or all wells on 1 property combined) capable of pumping 100,000 gallons a day or more. These need DNR approval. An ordinary house well does not. are within 2 miles, and what do they pump?
4. Is the parcel in a groundwater protection area, near a trout stream, or near a spring? Those trigger extra DNR review and also signal a sensitive aquifer.
5. Is there a well construction report on file, and what does it say about casing depth and grouting?
6. What’s the contamination picture: nitratenitrateFertilizer and manure that has leached into groundwater. Above 10 milligrams per liter it is a health risk, especially for infants, and you cannot fix your neighbor's fields., arsenic, radiumradiumA naturally radioactive element in southeastern Wisconsin's deep sandstone aquifer. It is what pushed Waukesha off its wells and onto Lake Michigan water., PFASPFASThe "forever chemicals" from firefighting foam and industrial processes. They do not break down, treatment is expensive and permanent, and standards keep tightening. Never in a standard water test unless you ask for it by name., and any BRRTS-listed site upgradient?

The checklist version is in ../04-due-diligence/CHECKLIST.md.

Next

04-federal-and-tribal.md, the senior rights nobody prices in.