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Water Rights/Case Library

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Edwards Aquifer Authority v. Day, 369 S.W.3d 814 (Tex. 2012)

Why this matters: Texas held that you own the groundwater under your land the way you own the oil, which means regulating it can require paying you. It’s the strongest property-rights position on groundwater in the country, and the mirror image of how Wisconsin thinks.

Doctrine: Groundwater ownership, regulatory takingsregulatory takingWhen a government rule restricts your property so severely that courts treat it as taking the property, which would require payment. Wisconsin courts have been unusually willing to say a shoreline rule is not one.

Case name and citation

Edwards 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. Authority v. Day, 369 S.W.3d 814 (Tex. 2012).

Court and year

Supreme Court of Texas. Decided February 24, 2012. Unanimous. Opinion by Justice Hecht.

One-line holding

Land ownership in Texas includes an interest in the groundwater in place beneath the land, that interest cannot be taken for public use without adequate compensation under the Texas Constitution, and a regulatory takingsregulatory takingWhen a government rule restricts your property so severely that courts treat it as taking the property, which would require payment. Wisconsin courts have been unusually willing to say a shoreline rule is not one. claim based on limiting groundwater withdrawal is analyzed under the Penn Central framework.

Facts

Burrell Day and Joel McDaniel bought roughly 380 acres in south central Texas in 1994, entirely within the Edwards 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.. The property had an existing well and a lake fed in part from it.

The Edwards Aquifer supplies south central Texas and is, in the legislature’s assessment, vital to the region’s residents, industry, ecology, and the state economy.

The Edwards Aquifer Authority was created by statute in 1993, the year before Day bought. Its enabling act capped total withdrawals and required permits, generally issued based on historical use during a defined period.

Day applied for a permit to withdraw 700 acre-feetacre-footEnough water to cover 1 acre a foot deep: 325,851 gallons. Roughly what 2 or 3 suburban households use in a year. per year for irrigation. The Authority granted 14 acre-feetacre-footEnough water to cover 1 acre a foot deep: 325,851 gallons. Roughly what 2 or 3 suburban households use in a year..

The gap came from the historical use test. Day could not establish enough historical use to support the larger amount, in part because the Authority found the water Day had drawn from the impoundment had become state surface water rather than groundwater.

Day sued, claiming a taking. The district court held there could be no taking as a matter of law. The court of appeals reversed and remanded. Both sides went to the Texas Supreme Court.

Does land ownership in Texas include an interest in groundwater in place that cannot be taken for public use without adequate compensation under article I, section 17(a) of the Texas Constitution?

Holding and reasoning

The court answered in the first paragraph: “We hold that it does.”

The reasoning ran by analogy to oil and gas. Texas has long recognized that a landowner owns the oil and gas in place beneath the surface, subject to 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.. The court held the same structure applies to groundwater. You own the water in place, and 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. governs how you and your neighbors may take it.

That distinguishes Texas from states like Oklahoma, where a landowner holds an exclusive license to develop groundwater rather than ownership of the water itself.

The court distinguished the older rule of capture cases as addressing liability between neighbors rather than the existence of a property interest against the government. Sipriano v. Great Spring Waters (1999) says your neighbor owes you nothing when they drain your well. That says nothing about whether the state owes you something when it limits your own pumping. See 1999-sipriano-v-great-spring-waters.md.

Having found a vested property interest, the court turned to the takings analysis. It looked at Lucas v. South Carolina Coastal Council and Penn Central Transportation Co. v. New York City, and directed that all relevant factors be considered rather than applying a rigid rule.

The court did not decide whether a taking had actually occurred. Because the case came up from summary judgment for the Authority, it affirmed the court of appeals and remanded to the district court to determine whether compensation was owed and how much.

It also criticized the Authority’s reliance on historical use as an unjustified departure from the permitting factors in the Texas Water Code.

Why it matters

This is the outer boundary of groundwater as private property in American law, and it creates a genuinely strange system when read with Sipriano.

Under Sipriano, a neighbor can pump your well dry and owe you nothing. Under Day, if the state limits that neighbor’s pumping to protect you, the state may owe the neighbor money.

Texas protects the extractor from both directions. Whatever you think of that as policy, it is coherent as property theory: the water in place is yours, capture is how it moves between private parties, and government interference with your interest triggers compensation.

The consequence for regulators is real. Groundwater conservation districts across Texas now operate knowing that stringent limits carry takings exposure. Bragg v. Edwards Aquifer Authority, decided by a Texas court of appeals in 2013 on remand from related litigation, awarded compensation to a pecan farm on these grounds.

Compare Wisconsin, and the difference in starting premise is total. Michels Pipeline describes groundwater use as a privilege that “does not represent an unqualified property right in ground waters.” See 1974-state-v-michels-pipeline.md. And Just v. Marinette County holds that a regulation preventing harm to a public resource is not a taking even when it destroys most of the land’s development value. See 1972-just-v-marinette-county.md.

Same country. Same Fifth Amendment. Opposite baselines, because the property interest is defined by state law and the states disagree about what you own.

That is also the deepest lesson of Casitas: federal takings analysis is only as strong as the state law property interest underneath it. See 2008-casitas-v-united-states.md.

What it means for a landowner today

Texas law does not apply to a Wisconsin parcel, and the contrast is the point.

In Wisconsin you do not own the groundwater under your land as a corporeal thing. You have a right to make 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. of it, subject to liability for unreasonable harm and subject to DNR permitting for large withdrawals, layered over a constitutional public trustpublic 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..

Practical implications:

  • Do not price a Wisconsin parcel on the theory that the aquifer beneath it is an asset you own and could sell or export. That theory does not work here.
  • Do not assume that a future restriction on your water use will be compensated. In Wisconsin the presumption runs the other way.
  • If you ever evaluate Texas or other rule-of-capture land, understand that the ownership premise cuts both ways: strong protection against regulators, essentially no protection against a neighbor with a bigger pump.

What to verify for a Wisconsin parcel: the well’s permitted status and capacity, whether any withdrawal on the parcel would cross the high capacity threshold, and the aquifer’s condition locally. Who verifies: a hydrogeologisthydrogeologistA geologist who specializes in groundwater. Worth hiring for acreage, tricky geology, or any large planned withdrawal. and the Wisconsin DNR.

Subsequent history / is it still good law

Good law as of July 2026 and a landmark of Texas water law.

On remand the Day litigation continued in the district court on the takings merits. The related Bragg litigation produced a compensation award affirmed by a Texas court of appeals in 2013, with the Texas Supreme Court declining review. [UNVERIFIED] as to the final disposition of Day’s own damages claim; confirm before relying on the outcome.

The Texas legislature responded in 2015 with legislation addressing groundwater ownership and district regulation. Groundwater conservation districts continue to regulate, now under the constraint that overly aggressive limits may require compensation.

Sources

Research demo, not legal advice. Facts current as of July 2026. Water law is state-specific and moves quickly, so confirm anything you plan to act on with a licensed attorney and the relevant state agency.