What Happens When Data Center Construction Floods My Land?

A Texas Landowner’s Resource Guide to Surface Water Diversion, Water Code Section 11.086, and Drainage Claims Against Data Center Developers

A developer strips the vegetation off a hundred acres next to you, regrades the whole tract so it falls toward your fence line, pours concrete pads and parking that shed every drop of rain, and builds a detention pond that was sized on paper and never worked in the field. The first real Hill Country gully-washer comes through, and water that used to spread out and soak into open ground now runs off that site in a sheet and stacks up on your bottomland. Your barn floods. Your pasture washes. A county road culvert that handled runoff fine for forty years cannot move the volume anymore.

Here is the short version before the analysis. In Texas, a landowner does not get to redraw the drainage on his own tract and push his stormwater onto yours. When a data center changes the natural flow of surface water and that change damages your land, you likely have a claim, and often a strong one. What decides whether you win it is proof and timing.

The practical lesson: you are not required to absorb their runoff

I have practiced real estate and water law in San Antonio for more than a quarter century, and I have called South Central Texas home my whole life. The most common misunderstanding I hear from landowners after a neighboring project floods them is that the developer had the right to grade his land however he wanted, and that the water is just gravity doing its job. That is wrong, and it is worth correcting on the first page.

Texas law draws a line between the natural flow of water and an altered flow. You take your neighbor’s water the way nature sends it. You do not have to take the water your neighbor manufactures by paving, grading, channeling, and concentrating it. A data center is one of the most aggressive changes to a rural tract you will ever see next door, because it converts open ground that soaked up rainfall into acres of roof, pad, and pavement that shed all of it. When the engineering is wrong, the detention is undersized, or the grading throws water at your fence line, the developer has stepped over that line, and the law gives you a remedy.

What “surface water” means and why a data center changes it

The statute protects you against the diversion of “surface water,” and that term has a specific meaning in Texas. See Section 11.021 of the Texas Water Code. Surface water is water that spreads diffusely over the ground from falling rain or melting snow and stays surface water only until it reaches a bed or channel in which water is accustomed to flow. Dietrich v. Goodman, 123 S.W.3d 413, 418 (Tex. App. Houston [14th Dist.] 2003, no pet.). Its defining feature is that it does not follow a defined course. Once that water gathers into a creek, gully, or other well-defined watercourse, or once it is put under control in a ditch, pipe, or pond, it may no longer be surface water and the statute may not reach it. Id. at 418 to 419.

This matters more than it may sound, because a data center attacks the diffused stage of the water cycle. On raw land, rain falls and much of it spreads, ponds briefly, and soaks in. After construction, the impervious cover sheds nearly all of it at once, and the site grading decides where it goes. Engineers call the result increased runoff volume and higher peak flow. In plain terms, more water leaves the site, it leaves faster, and it leaves at the low corner the developer chose. When that redirected sheet flow lands on you, the natural flow onto your land has been changed by human hands, and that is the fact pattern the statute was written for.

Expect the developer to argue that what hit you was not surface water at all but “flood water,” which the State, not a private owner, has the duty to control. Watch that move closely. The Waco Court of Appeals rejected it in Vien v. Del Buono, holding that a watershed is not a watercourse, because if it were, rain would lose its character as diffused surface water the instant it touched the ground. No. 10-09-00318-CV, 2010 Tex. App. LEXIS 10011, at 9 to 12 (Tex. App. Waco Dec. 15, 2010, pet. denied). Diffused runoff that a graded pad or driveway redirects onto your land is surface water, and the label “flood water” does not make the developer’s diversion disappear.

Texas follows the civil law rule

Two competing rules exist in American water law. Under the old common enemy doctrine, surface water is treated as an enemy every owner may fight off however he can, and the neighbor be damned. Texas rejected that approach. Texas follows the civil law rule, which recognizes that lower land owes a natural drainage easement to higher land, but only for the water that would naturally flow. The higher owner cannot enlarge, concentrate, or redirect that flow to overload the lower owner.

The Texas Supreme Court settled this in Kraft v. Langford, 565 S.W.2d 223 (Tex. 1978), holding that the statute now codified at Section 11.086 established the civil law rule as the law governing all property in the state. A higher owner “cannot burden adjacent lands with surface water he accumulates or discharges except in the same manner in which it would naturally flow.” Id. at 228. The lower owner must receive the natural flow, but “is not required to receive these waters except in their natural condition, untouched by the hands of man.” Bunch v. Thomas, 121 Tex. 225, 49 S.W.2d 421, 423 (Tex. 1932); accord Muniz v. Dugi, No. 04-20-00528-CV, 2022 Tex. App. LEXIS 3173, at 20 to 21 (Tex. App. San Antonio May 11, 2022, no pet.). The foundation was laid in Miller v. Letzerich, 121 Tex. 248, 49 S.W.2d 404 (Tex. 1932). The rule has been stable for generations. What is new is the scale of the projects testing it.

Water Code Section 11.086 is the statute that protects you

The heart of a Texas flooding case is a short, blunt statute. Section 11.086 of the Texas Water Code reads:

(a) No person may divert or impound the natural flow of surface waters in this state, or permit a diversion or impounding by him to continue, in a manner that damages the property of another by the overflow of the water diverted or impounded.

(b) A person whose property is injured by an overflow of water caused by an unlawful diversion or impounding has remedies at law and in equity and may recover damages occasioned by the overflow.

Texas courts have distilled the statutory claim to three elements: (1) a diversion or impoundment of surface water, (2) that causes, (3) damage to the plaintiff’s property. Dietrich, 123 S.W.3d at 417 (citing Bily v. Omni Equities, Inc., 731 S.W.2d 606, 611 (Tex. App. Houston [14th Dist.] 1987, writ ref’d n.r.e.)). Read subsection (a) carefully, because developers and their carriers always try to read words into it that are not there. The statute does not require malice. It does not require negligence. Liability is strict. It does not excuse the developer because he hired a licensed engineer or pulled the right permit. If you prove the three elements, subsection (b) gives you both damages and equitable relief.

Notice also the phrase “or permit a diversion or impounding by him to continue.” That language reaches the developer who did not build the problem himself but bought or operates a site that keeps diverting water onto you. It is why a later owner who knew his property was flooding the neighbor and did nothing was held liable in Vien. 2010 Tex. App. LEXIS 10011, at 12 to 15. An ongoing diversion is an ongoing violation.

Diversion and impoundment are the two ways a data center floods you

The statute names two distinct wrongs, and a data center can commit either or both.

Diversion sends the water somewhere it did not naturally go

Diversion is redirection. The developer regrades the tract, cuts a swale, crowns a pad, or aims a discharge so that water which once spread across the site or drained toward a different boundary now runs toward you. The classic data center version is mass grading that tilts a large footprint toward the nearest low property line, combined with concentrated outfalls that dump collected runoff at a single point instead of the sheet flow that existed before.

Impoundment holds water back and then releases or backs it up

Impoundment is obstruction or detention. A detention pond, a berm, a raised pad, or a compacted construction entrance can dam the natural drainage. Sometimes the harm is the backup itself, when the obstruction ponds water onto upstream land. Sometimes the harm comes on release, when an undersized or poorly controlled pond discharges a surge downstream during a storm. Detention built to the wrong volume, or never built at all, is one of the most common failures on large sites. In one case, two apartment developments on higher ground failed to build proper detention ponds and flooded the neighbor’s property with even ordinary rain. Scott v. S2S Domain Waco Assocs., LLC, No. 10-20-00133-CV, 2021 Tex. App. LEXIS 9631, at 24 to 26 (Tex. App. Waco Dec. 1, 2021, pet. denied).

Construction that changes the grade is a classic diversion

You do not have to theorize about how this plays out. The San Antonio Court of Appeals decided it on facts that map cleanly onto a data center build. In Muniz v. Dugi, a neighbor’s construction altered the grade of the higher lot, built up a driveway and fill, and sent surface water that had never crossed the line before straight onto the lower owner’s property, into the center of a metal shop. 2022 Tex. App. LEXIS 3173, at 18 to 21. The trial court found, and the appeals court affirmed, that the construction altered the grade, that the altered grade diverted the water, that but for the altered grade the water would not have been diverted, and that the diversion caused the damage. Id. at 20. The court called it “a classic example of surface water, water diffused over the ground from falling rain, diverted by a change in elevation because of the construction of the development.” Id. (quoting Marin Real Estate Partners, L.P. v. Vogt, 373 S.W.3d 57, 84 (Tex. App. San Antonio 2011, no pet.)).

Swap the driveway and fill for a data center’s pads, parking, and mass grading, and you have the same case at a far larger scale. A change in elevation from construction is not a defense. It is the violation.

A permit is not permission to flood your land

Every large construction project in Texas that disturbs one acre or more must obtain stormwater authorization from the Texas Commission on Environmental Quality under its Construction General Permit, file a Notice of Intent, and prepare and follow a Stormwater Pollution Prevention Plan. On top of that, the county or municipality usually requires a drainage study and a floodplain development permit if any part of the site touches a mapped flood zone. Developers wave these approvals around like a shield.

They are not a shield against you. A TCEQ stormwater permit is a water-quality permission designed to keep sediment and pollutants out of state waters. It does not adjudicate the private property rights between the developer and the neighbor, and it does not grant anyone the right to divert or impound surface water onto adjoining land. Section 11.086, as the Supreme Court explained in Kraft, is a rule of property that defines the rights between owners. The point is not academic. In the most recent Texas Supreme Court flooding decision, the developer had hired an international engineering firm to design its drainage, had a second firm review it, and had the county drainage district approve the plan, and it was still sued when the neighbors flooded. See Tenaris Bay City Inc. v. Ellisor, 718 S.W.3d 193 (Tex. 2025). Compliance with a public permit is not a defense to a private diversion claim.

Your claims run beyond the statute

Section 11.086 is the anchor, but a well-built flooding case usually pleads more than one theory, because each carries different proof, different remedies, and different deadlines.

Private nuisance covers the interference with your use of the land

Recurrent flooding that interferes with the normal use and enjoyment of your property is a classic private nuisance. Texas treats nuisance as temporary or permanent, and the distinction drives both your damages and your deadline, as explained below. Getting that characterization right is one of the most consequential early decisions in the case.

Negligence reaches the engineering and the construction

When a project floods a neighbor, the drainage design, the grading, or the construction practices usually fell below the standard of care. A common-law negligence theory could bring in the developer, the general contractor, and the design engineer, and it exists independent of the statute. This liability, however, is subject to the economic loss doctrine. The higher owner’s duty to release surface water only as it naturally flows is itself a legal duty a court can enforce in negligence. Vien, 2010 Tex. App. LEXIS 10011, at 10 to 12.

Trespass covers the physical invasion of water and sediment

Water, mud, and debris pushed onto your land by an altered drainage pattern can support a trespass claim. Trespass is often useful where the invasion is physical and provable even while damages are still developing.

You can recover damages and stop the flooding

Subsection (b) of the statute gives you remedies at law and in equity. In practice that means two things.

First, money. You can recover for the damage to your land, which may include the cost to repair, the loss of use, and damage to structures, crops, fences, and roads. Whether the injury is temporary or permanent controls the measure. Permanent injury is generally measured by the loss in market value; temporary injury is generally measured by the cost to repair plus lost use. Damaged household contents are valued by their worth to you, not by a secondhand market price. Vien, 2010 Tex. App. LEXIS 10011, at 21 to 24.

Second, and often more important to a landowner who wants the water to stop, you can get an injunction while your claim is timely. Texas courts have ordered defendants to tear out a berm that channeled runoff, Boatman v. Lites, 888 S.W.2d 90, 92 to 93 (Tex. App. Tyler 1994, no writ), and to build an engineered retaining wall or retention structure to keep construction runoff on the developer’s own land, Muniz, 2022 Tex. App. LEXIS 3173, at 20 to 21. You do not have to prove the injury is “serious” or that money could never repair it in order to earn equitable relief under this statute. Boatman, 888 S.W.2d at 93. For many landowners, the order that fixes the drainage is worth more than the check.

Causation is where these cases are won or lost

Read the newest decision from the Texas Supreme Court before you assume a flooding case wins itself. In Tenaris Bay City Inc. v. Ellisor, 718 S.W.3d 193 (Tex. 2025), a manufacturing plant replaced a sod farm with impervious cover and a designed drainage system, Hurricane Harvey came through, and thirty homes flooded. A jury awarded 2.8 million dollars. The Supreme Court reversed and rendered a take-nothing judgment because the homeowners did not prove causation. Their own engineer admitted he had not done the drainage analysis needed to show that these particular homes would not have flooded but for the plant. Id. at 198 to 199. The Court held that proof the defendant was negligent, even woefully negligent, is not proof that the plaintiff’s land would not have flooded anyway, and that in a case of this kind causation “will generally require proof by expert testimony.” Id. at 201 to 203.

That is a burden, not a bar, and it cuts the landowner’s way when the work is done right. A plaintiff must prove the unlawful diversion caused damage that would not have resulted but for the diversion. Id. at 200. In an ordinary rain, where a graded pad plainly redirects sheet flow onto you, that link can be straightforward, as it was in Muniz. In a historic storm that floods a whole region, you need a qualified hydrologist or civil engineer who will study the topography, model the runoff, and actually reach the but-for conclusion. The cases that fail are the ones where no one did that work.

A big storm is not an automatic act of God defense

Developers love to blame the sky. When your land floods in a heavy rain, expect to hear that the storm, not the data center, was the cause, and that an act of God excuses everything. Texas law does not hand them that defense for free. An event is an act of God only if it is caused directly and exclusively by the violence of nature, without human intervention, and could not have been prevented by reasonable care. Where human negligence is a proximate cause, it is not an act of God. In Vien, the county was declared a disaster area and the precinct was called the hardest hit, yet the court still held the developer liable because the experts agreed the constructed driveway caused the neighbor’s home to flood. 2010 Tex. App. LEXIS 10011, at 15 to 17.

Put Vien and Tenaris side by side and the lesson is clear. A catastrophic storm does not beat you if you prove the development made the difference between a flooded property and a dry one. It beats you if you do not. The variable is not the size of the storm. It is whether you brought the engineering to isolate the development’s contribution.

The deadline to sue is shorter than you think

Texas gives you two years to bring a claim for injury to real property, and that two-year clock applies to your Section 11.086 claim, your nuisance claim, your negligence claim, and your trespass claim alike. Scott, 2021 Tex. App. LEXIS 9631, at 21 to 28; Fam. Dollar Stores of Tex., LLC v. JLMH Invs., LLC, 2026 Tex. LEXIS 658 (Tex. 2026), reversing in part JLMH Invs., LLC v. Family Dollar Stores of Tex., LLC, 2024 Tex. App. LEXIS 4143 (Tex. App. Fort Worth 2024). The hard part is when the clock starts, and the answer turns on whether the flooding is a permanent nuisance or a temporary one.

That distinction can make or break your case, and it cuts both ways. When a permanent structure such as a store, a pad, or a drainage system floods a neighbor “every time it rained,” courts treat the nuisance as permanent as a matter of law, and a permanent nuisance accrues when the flooding first occurs or is discovered, even if you do not yet know the cause or the full extent of the damage. In JLMH, a commercial building next door flooded a neighbor that way, the owner sued about four years after the flooding started, and the flooding claims were held time-barred, a result the Texas Supreme Court confirmed in 2026. 2026 Tex. LEXIS 658, at 16 to 18. But where the flooding is irregular and its future impact cannot be estimated with reasonable certainty, the nuisance can be temporary, and a temporary nuisance accrues anew with each flood, so each event within two years of suit is live. In Scott, the neighbor’s flooding was sporadic and unpredictable in timing and severity, the court held the temporary or permanent question was a fact issue, and it revived claims the trial court had thrown out on limitations. 2021 Tex. App. LEXIS 9631, at 22 to 28.

For a while it looked like a claim to stop the flooding might outlast a claim for money. The Texas Supreme Court closed that door in 2026. In the same JLMH case, the Court held that there is no stand-alone right to abate a nuisance, and that a remedy, including an injunction, is available only if the underlying claim is not time-barred. Fam. Dollar Stores of Tex., LLC v. JLMH Invs., LLC, 2026 Tex. LEXIS 658, at 16 to 19 (Tex. 2026). Once the two-year clock runs on your flooding claim, it takes both your damages and your injunction with it. That makes the deadline the whole ballgame, and it is why you cannot afford to wait and see whether the flooding happens again.

What this means for South Central Texas landowners

The data center build-out across Bexar, Medina, Comal, Guadalupe, and Atascosa Counties is putting enormous impervious footprints onto ground that used to soak up its own rain. Some of these projects are engineered well. Some are not, and the landowner downhill is the one who finds out. If you are that landowner, the law is better for you than you may think. You are not required to accept manufactured runoff. Water Code Section 11.086 and the civil law rule give you a direct, strict-liability claim for both money and an order to make the flooding stop, and a developer’s permit does not take that claim away.

What separates the landowners who recover from the ones who do not is proof and timing. Prove causation with a real engineer who does the analysis. Document the water the first time it happens, and every time after. Understand that the deadline can start at the very first flood, and that whether the nuisance is temporary or permanent may decide your case. Get advice before the developer reshapes the ground and the record. Handle those things, and you protect both your land and your leverage.

This guide is part of our data center landowner series. If your situation is a sale rather than a flood, see our guide to selling your property for a data center. If you kept your land and now live beside the development, see our guide to living next to a data center.