Tenaris Bay City Inc. v. Ricky Ellisor

Supreme Court of Texas
══════════
No. 23-0808
══════════

Tenaris Bay City Inc.,
Petitioner,

v.

Ricky Ellisor, et al.,
Respondents

═══════════════════════════════════════
On Petition for Review from the
Court of Appeals for the Fourteenth District of Texas
═══════════════════════════════════════

Argued February 19, 2025

CHIEF JUSTICE BLACKLOCK delivered the opinion of the Court.

Justice Huddle and Justice Young did not participate in the
decision.

Hurricane Harvey, one of the most destructive storms in Texas
history, struck the gulf coast in the summer of 2017. Thousands of
properties were flooded. A group of flooded homeowners in Matagorda
County sued a nearby pipeline manufacturing company, blaming design
defects at its facility for flood damage at thirty homes in the area. After
a favorable jury verdict, the district court rendered judgment for the
plaintiffs, and the court of appeals affirmed.
The question presented is whether the plaintiffs failed to prove a
basic element of their case—that the defendant, as opposed to merely
the extraordinary rainfall combined with other environmental factors,
caused their houses to flood. We conclude there was legally insufficient
evidence that the plaintiffs’ houses would not have flooded but for the
defendant’s negligence. Houses all throughout this flood-prone region
were at risk of flooding during the storm, regardless of the presence of
nearby industrial facilities. To recover on their claims, the plaintiffs
needed to prove that their houses would not have flooded during
Hurricane Harvey if not for the presence of the defendant’s defectively
designed facility. Challenged to draw that key conclusion, the plaintiffs’
expert witness declined to do so. Instead, he acknowledged that he could
have done the scientific analysis necessary to know the cause of the
flooding of these particular houses, but he had not done it.
In flooding cases following catastrophic rains, causation may
often be hard to prove. But pinning the consequences of a historic act of
God on your neighbor is no small thing. Thousands of properties across
southeast Texas were damaged by flooding during Hurricane Harvey.
These plaintiffs were certainly entitled to come to court to contend that
their Harvey flooding was not merely Harvey’s fault but was this
defendant’s fault. But the natural, default explanation for flood damage
during a historic and unpredictable rain event is the storm itself, not the
actions of neighboring property owners. Those who wish to prove
otherwise must demonstrate, with reliable evidence, that their flood

2
damage would not have occurred if not for their neighbor’s tortious
actions. Because the plaintiffs in this case did not carry that burden,
the judgments of the lower courts are reversed, and judgment is
rendered for the defendant.
I.
The plaintiffs own homes in the cities of Van Vleck and Bay City
in Matagorda County. Defendant Tenaris Bay City Inc. operates a pipe
fabrication facility in Bay City. The Tenaris plant occupies land
previously used as a sod farm. To address the concern that replacing a
sod farm with impervious cover would increase flooding, Tenaris hired
Fluor Enterprises, an international engineering firm, to design and
build a drainage system for its new plant. Jones & Carter, a
construction and design firm, reviewed the drainage plan and
recommended that the county drainage district approve it. The district
approved the plan. The system included water detention ponds
surrounded by a raised “berm” to prevent uncontrolled runoff.
Hurricane Harvey struck in August 2017, and the plaintiffs’
thirty homes were flooded. Expert testimony at trial described
Hurricane Harvey as “the most significant tropical cyclone rainfall event
in United States history, both in scope and peak rainfall amounts, since
reliable rainfall records began around the 1880s.” It caused great
damage all over southeast Texas, including Matagorda County, which
suffered over $500 million in property damage. As to the severity of
Harvey in Matagorda County, there was evidence that other areas of the
state were harder hit. However, the lay and expert testimony showed
that Harvey dumped 21.6 inches in Matagorda County over four days

3
and that it was either the worst or the second-worst hurricane (after
Carla) in memory.
The plaintiffs sued Tenaris, Fluor, and Jones & Carter under
theories of negligence, gross negligence, negligence per se, and negligent
nuisance. Jones & Carter settled before trial. Fluor settled after trial.
By agreement, the plaintiffs’ properties were divided into three zones,
and the case proceeded to an initial trial on liability only. On the
question of causation, the plaintiffs relied primarily on the expert
testimony of Gabriel Novak, a civil engineer. The substance of his
testimony plays a key role in the outcome of this appeal, as detailed
below.
The district court directed a verdict on gross negligence in favor
of Tenaris. The court submitted the other theories of negligence to the
jury. The jury found Tenaris liable on all three negligence theories as
to all three zones. Tenaris and the plaintiffs agreed that the total
damages were $2.8 million. The district court rendered judgment for
that amount plus interest. Tenaris appealed, and the court of appeals
affirmed. 704 S.W.3d 37, 53 (Tex. App.—Houston [14th Dist.] 2023).
II.
A.
“The elements of a negligence cause of action are the existence of
a legal duty, a breach of that duty, and damages proximately caused by
the breach.” Rodriguez-Escobar v. Goss, 392 S.W.3d 109, 113 (Tex. 2013)
(quoting IHS Cedars Treatment Ctr. Of DeSoto, Tex., Inc. v. Mason,
143 S.W.3d 794, 798 (Tex. 2004)). Proximate cause has two elements:
(1) cause in fact, and (2) foreseeability. Id.; IHS, 143 S.W.3d at 798.

4
Cause in fact, in turn, also has two essential components: (1) “but for”
causation, and (2) “substantial factor” causation. Pediatrics Cool Care
v. Thompson, 649 S.W.3d 152, 158 (Tex. 2022). The plaintiff must
establish both elements of cause in fact in order to prevail on a
negligence claim. See id.; Goss, 392 S.W.3d at 113; Transcon. Ins. Co. v.
Crump, 330 S.W.3d 211, 221–23 (Tex. 2010); Ford v. Ledesma,
242 S.W.3d 32, 45–46 (Tex. 2007); IHS, 143 S.W.3d at 798–99.
The cause-in-fact standard thus “requires not only that the act or
omission be a substantial factor but also that it be a but-for cause of the
injury or occurrence,” and “a cause-in-fact definition that omits the
but-for component [is] ‘incomplete.’” Rogers v. Zanetti, 518 S.W.3d 394,
403 (Tex. 2017). The defendant’s negligence is the “but for” cause of an
injury if, “without the act or omission, the harm would not have
occurred.” Pediatrics, 649 S.W.3d at 158 (quoting Gunn v. McCoy,
554 S.W.3d 645, 658 (Tex. 2018)). The jury charge in this case was
consistent with these standards. It defined proximate cause to include
foreseeability as well as “actual causation,” which it described as
requiring proof that the defendant’s negligence was “a substantial factor
in bringing about an injury, and without which cause such injury would
not have occurred.”
Tenaris contends there was legally insufficient evidence
demonstrating that, but for the presence of its facility, the plaintiffs’
houses would not have flooded during Hurricane Harvey. After
reviewing the record, we must agree. The plaintiffs’ expert witness
criticized Fluor’s decision “to go with a very large drainage basin and
shift a lot of flow” to one point on the Tenaris property called

5
“Outflow 1.” His “fundamental opinion” was that the drainage facility’s
design allowed too much water to be directed toward Outflow 1. This
design, in his view, caused “additional flooding elsewhere in Van Vleck
or Bay City.”
Novak’s testimony provided sufficient evidence that design flaws
at the Tenaris facility contributed to some additional flooding in the local
area during Hurricane Harvey. But that fact alone is no evidence that
anything Tenaris did or did not do was a but-for cause of the flood
damage at any of the thirty particular properties at issue. Novak did
not and could not say whether, for any of the thirty properties spread
throughout the two towns, the flood damage they suffered would not
have occurred but for the additional flooding he attributed to Tenaris:
Q: Okay. And so if the jury [is] going to be asked: Hey
what caused these poor folks to have their homes
flooded during Hurricane Harvey, you actually can’t
answer that question, can you?
A: As far as to the specific homes?
Q: Yes, sir.
A: No, I cannot answer that question.
Q: You can’t answer it about any of these places here in
Van Vleck or down south in Bay City where the
plaintiffs live, can you?
A: With – for – as far as a detailed analysis? No.
....
Q: Okay. You can’t put your seal or your stamp on any
kind of conclusion in this case about what caused
any of these plaintiffs’ homes to flood, can you, sir?
A: A defin – I – not as far as a definitive conclusion.

6
Q: And you can’t give us a general conclusion, because
you haven’t done the work that you just told me
you’d have to do to reach that conclusion –
A: For each –
Q: – right?
A: That is correct.
Novak acknowledged that he could have determined whether the
Tenaris facility caused plaintiffs’ homes to flood. To do so, he would have
looked at topographic information to create “a detailed drainage
analysis” and “hydrographic models of that area.” He would have
consulted “soil maps” from the Natural Resources Conservation Service
and conducted a “study of all of the waterways” in the relevant area. He
did not do this analysis, however:
Q: Okay. And the five things you told us that you would
have to look at to figure out what actually caused the
flooding at any of these people’s homes, right? Are
those things that you, in your professional
experience and career, you would be able to do?
A: Yes.
Q: Okay. But you haven’t, have you?
A: Done a detailed analysis of any of the specific
plaintiff[s’] homes?
Q: Right.
A: No, I have not.
Q: In fact, you haven’t [done] a general flooding
analysis at all about what happened in Van Vleck,
Texas, have you, sir?
A: No. I have not.
Regarding the design of Outflow 1, Novak testified:

7
A: Let me make sure I understand your question here.
The question is: Have I looked at the – done an
analysis to compute the flooding effects off of
Outflow 1?
Q: Fair – that’s very well put. Very well put. Have you
done that?
A: I have not done that – that full of an analysis, no.
Q: Have you done any – any flooding analysis?
A: I have not done any flooding analysis in that area.
Q: Whatsoever?
A: Whatsoever.
At another point, Novak testified that Tenaris’s conduct was “a
factor” in bringing about the plaintiffs’ harm, but he declined to confirm
that the conduct was a substantial factor, and he never testified at all to
the essential element of but-for causation:
Q: Mr. Novak, based on your education, work
experience, and your modelling, have you – do you
have an opinion based on a reasonable degree of
engineering probability whether or not the storm
water drainage design plan as written by Fluor, and
as implemented by Tenaris was a substantial factor
in bringing about the flooding of plaintiffs’
properties?
A: Yes.
Q: Okay. Well, what is your opinion?
A: My opinion is that the failure of the Fluor design and
its implementation was a factor in the flooding of the
plaintiffs’ properties.
None of Novak’s testimony supports the conclusion that Tenaris’s
defectively designed facility was a but-for cause of the flood damage
suffered at the properties in question. The problem is not merely that

8
his testimony was devoid of any such opinion or of any facts from which
such a conclusion could reasonably be drawn. The further problem is
that he candidly admitted he had not attempted to determine the effect
of Tenaris’s facility on any of the subject properties, and he had not
attempted to determine whether any of the properties would have
suffered comparable flood damage in the absence of the facility’s alleged
defects. As we have stated before, expert testimony on causation is
fundamentally unreliable if the expert fails to exclude other plausible
causes with reasonable certainty. E.g., Helena Chem. Co. v. Cox,
664 S.W.3d 66, 80–81 (Tex. 2023); JLG Trucking, LLC v. Garza,
466 S.W.3d 157, 162 (Tex. 2015); Crump, 330 S.W.3d at 218. Novak
made no attempt at all to exclude the exceptional hurricane itself and
other environmental factors in the region that might plausibly have
caused the plaintiffs’ damages irrespective of any contribution the
Tenaris plant made to flooding in the area. His testimony was
insufficient to establish but-for causation, and there was no other
evidence from which a jury could reasonably infer that the Tenaris
facility—rather than merely the storm itself—was a but-for cause of the
plaintiffs’ damages.
B.
The plaintiffs point out that they recovered on three separate
theories—negligence, negligence per se, and nuisance—and they
complain that Tenaris focuses its arguments only on the causation
element of negligence. Tenaris correctly responds, however, that
sufficient evidence of but-for causation was required under all of the
plaintiffs’ theories of liability, both as a matter of Texas law and as a

9
matter of the jury charge given in this case. As with their negligence
claim, under each of their alternative theories the plaintiffs had to prove
that their flood damage would not have occurred but for Tenaris’s
tortious conduct. As discussed above, they did not do so.
An actionable nuisance can arise from intentional conduct,
negligence, or in the case of certain ultra-hazardous activities, strict
liability. Crosstex N. Tex. Pipeline, L.P. v. Gardiner, 505 S.W.3d 580,
604–09 (Tex. 2016). The plaintiffs’ nuisance claim embraced a
negligence theory. A negligent nuisance claim “is governed by ordinary
negligence principles,” which require the plaintiff to prove a legal duty,
breach of that duty, and damages proximately caused by the breach. Id.
at 607. The nuisance portion of the jury charge instructed that
proximate cause means a cause that was foreseeable and “that was a
substantial factor in bringing about an injury, and without which cause
such injury would not have occurred.” Thus, the nuisance charge both
correctly required a showing of proximate cause and correctly defined
proximate cause to include its required element of but-for causation.
The insufficiency of the evidence of but-for causation is therefore just as
fatal to the plaintiffs’ nuisance claim as it is to their negligence claim.
“Negligence per se” is merely a species of negligence, in which the
breach-of-duty element is established by showing the violation of a
statute or regulation. See Mo. Pac. R.R. v. Am. Statesman, 552 S.W.2d
99, 102 (Tex. 1977). The plaintiffs’ negligence per se claim was based on
section 11.086 of the Water Code, which provides:
(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

10
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.
In general, a negligence per se claim retains the usual
requirements of proximate cause. See Mo. Pac. R.R., 552 S.W.2d at 103.
Section 11.086 reiterates the causation requirement by specifying that
liability attaches only if the injury to property was “caused by an
unlawful diversion or impounding” of water and that the damages
available are those “occasioned by the overflow.” TEX. WATER CODE
§ 11.086(b). These textual causation requirements only reinforce the
proximate causation requirement that would normally apply to any
negligence per se claim. This means, as another court applying
section 11.086 has observed, that “[t]he plaintiff carries the burden to
prove the unlawful diversion caused damages to plaintiff’s property
which would not have resulted but for such unlawful diversion.”
Contreras v. Bennett, 361 S.W.3d 174, 178 (Tex. App.—El Paso 2011, no
pet.); accord Benavides v. Gonzalez, 396 S.W.2d 512, 514 (Tex. App.—
San Antonio 1965, no writ) (interpreting predecessor statute prohibiting
diversion or impoundment of surface waters). Once again, these legal
standards are consistent with the jury charge in this case, which
instructed that “[t]he diversion or impounding of surface water, if any,
must have caused damages to Plaintiffs’ properties and without which
cause such injury would not have occurred.” The failure of but-for
causation therefore defeats the plaintiffs’ negligence per se claims as
well.

11
C.
The parties argue over whether the court of appeals dispensed
with the but-for causation requirement and improperly rested its
causation holding on substantial-factor causation alone. See 704 S.W.3d
at 47–48 (“Viewed in the light most favorable to the appellees, we hold
there was legally sufficient evidence to support the jurors’ finding that
Tenaris was a substantial factor in bringing about appellees’ harm.”).
We do not understand the court of appeals to have done so, but in any
event, the law (and the jury charge) required the plaintiffs to prove
but-for causation, which they failed to do.
Our decision in Bostic v. Georgia-Pacific Corp., 439 S.W.3d 332,
344–46 (Tex. 2014), has no bearing on our application of the usual
requirements of proximate causation to this case. Bostic was an
asbestos case in which the Court adjusted the but-for causation
requirement due to the nature of asbestos injury. Observing that
asbestos exposure from various sources can happen throughout a
person’s life, the Court did not require the plaintiff to “establish[] which
fibers from which defendant actually caused the disease” because doing
so “is not humanly possible.” Id. at 344. We have since held that this
relaxed standard will apply only in rare cases. See, e.g., Rogers,
518 S.W.3d at 403. It does not apply here. There is no contention that
it “is not humanly possible”—or anything close to that—to reliably
demonstrate that water flowing from the Tenaris facility caused the
flooding of these particular properties. The plaintiffs’ expert testified
that he could have determined the cause of flooding at the plaintiffs’

12
houses by tracing the runoff from Tenaris’s property to each property,
but for whatever reason he did not do so.
The plaintiffs contend that expert testimony was not necessarily
required to prove causation. The court of appeals likewise suggested
that lay testimony alone was sufficient. 704 S.W.3d at 47. We disagree.
There are surely flooding cases in which the cause of flooding is
straightforward enough that a factfinder may permissibly rely only on
lay testimony when asked whether the defendant caused the plaintiff’s
flooding. This was not remotely such a case.
“Expert testimony is required when an issue involves matters
beyond jurors’ common understanding.” Mack Trucks, Inc. v. Tamez,
206 S.W.3d 572, 583 (Tex. 2006). The plaintiffs’ counsel agreed before
trial that expert testimony was required to establish causation. 1 The
court agreed as well. The plaintiffs’ expert, Novak, testified that he
would have had to conduct a complicated analysis of data, maps, and
models to determine what caused plaintiffs’ properties to flood. Such an
analysis was by no means impossible, but neither was it within the
common understanding of jurors. The flow of flood waters across
relatively flat terrain, and the multitude of factors affecting the
propensity of any particular gulf-coast property to flood at any given
time, are generally matters that are not susceptible to proof solely by

1 In opposing an attempt to add the sod farm as a responsible third

party, the plaintiffs’ counsel insisted, correctly, that “there has to be a
causation opinion. . . . If we are talking about I had no expert witness, no
engineer, no one else, and I put a plaintiff up there that said, ‘I think the water
came [from] Tenaris,’ that’s not evidence where we could have this case.
There’d be a no evidence motion filed saying: You can’t prove causation.”

13
lay testimony. When thousands of properties are flooded during a
historic coastal rainfall, proving that your property’s flood damage was
caused by your neighbor rather than simply by the storm will generally
require proof by expert testimony. The plaintiffs took on that burden
and tried their case that way, as they should have, but as explained
above, their expert could not provide any opinion on the essential
question of but-for causation.
On similar facts, we held in City of Keller v. Wilson that proving
whether a real estate development increased flooding on neighboring
properties required expert testimony. 168 S.W.3d 802, 829 (Tex. 2005).
The Court explained that “[c]alculating the effect of detention ponds and
absorption in a grassy drainage ditch forty-five feet wide and over two
hundred yards long required hydrological formulas, computer models,
and mathematical calculations.” Id. Similarly here, Novak testified
that to determine what caused the plaintiffs’ houses to flood, he would
have needed to (1) study United States Geological Survey topographic
maps, (2) perform a detailed drainage analysis, (3) create computerized
hydrological models, (4) look at Natural Resources Conservation Service
soil maps, and (5) study all the relevant waterways. This may have
proved time-consuming and expensive, but it was not impossible. No
matter the difficulty or expense involved in mustering the required
evidence, we cannot lightly dispense, in this case or any other, with the
bedrock requirement of proof that the defendant actually caused the
plaintiff’s damages.
The plaintiffs rely heavily on another flooding case, Tarrant
Regional Water District v. Gragg, 151 S.W.3d 546 (Tex. 2004). They read

14
Gragg to excuse a lack of expert testimony on causation and to dispense
with the but-for causation requirement in flooding cases. The latter
point is belied by Gragg’s clear statement that “Gragg was required to
prove that the same damaging floods would not have occurred under the
same heavy rainfall conditions had the dam not been constructed.” Id.
at 554. Far from retreating from the usual but-for causation
requirement, Gragg insists on it.
As for the requirement of expert testimony, Gragg relied on both
expert testimony and lay testimony in holding that sufficient evidence
demonstrated causation. Id. at 551–54. But even if we had found lay
testimony alone to be sufficient in Gragg, that would by no means
compel the same result here. Gragg involved water discharged from a
single floodgate, which flowed downstream in a single river and
damaged a single ranch. Demonstrating causation was therefore not
nearly as complicated as doing so in a case like this one, where an
extraordinary volume of rain fell on vast swaths of acreage in a
relatively flat area and then moved from one property to another in ways
that are not at all obvious to non-experts. The water flow depended on
slight elevation differences, multiple small channels carrying water in
various directions, varying amounts of rainfall, varying permeability of
the ground, wind, impervious cover, adjacent water flows, etc. Without
the help of expert testimony, no factfinder—judge or jury—could
reasonably have concluded that the flooding suffered at these thirty
houses during Hurricane Harvey would not have occurred but for
Tenaris’s facility.

15
The plaintiffs focus much attention on evidence that a portion of
the drainage berm was built 43 feet high instead of the designed height
of 44 feet, and they blame this failure for the outflow of water from the
facility. They also emphasize Tenaris’s evident failure to perform proper
maintenance on the drainage system in various respects. As
incriminating as this evidence may be, it can establish only that Tenaris
was negligent. Proof that the defendant was negligent—even vivid proof
that the defendant was woefully negligent—is not proof that the
plaintiff’s injury would not have occurred but for the defendant’s
negligence.
It will not always be true that proving causation requires
mustering additional evidence beyond the evidence demonstrating the
defendant’s negligence. In many car wreck cases, for instance, proof of
the way in which the defendant’s vehicle struck the plaintiff’s may often
be sufficient evidence both of the defendant’s negligence and of the
defendant’s causal responsibility for the plaintiff’s injuries. But when
the allegation is that, if not for the defendant’s negligence, certain pieces
of property would not have flooded during a catastrophic rain event that
flooded many thousands of other properties in the area, proof of the
defendant’s negligence is no proof of causation. In such a case, the
plaintiff must proffer reliable evidence indicating that the defendant’s
negligence is what made the difference between a flooded home and a
dry one during a storm that flooded thousands of homes all on its own.
There is no such evidence in this record, and the only witness in a
position to provide such evidence pointedly declined to do so.

16
Finally, the plaintiffs testified that their properties had never
flooded before, even during similarly drenching rains. But such
evidence is not nearly enough to prove that Tenaris caused their flooding
during Hurricane Harvey, either on its own or in combination with
Novak’s testimony. In any community near the gulf coast, gradual
changes to impervious cover, subsidence of the earth, extreme weather
events, and other factors may alter a property’s propensity to flood over
the years. There are many reasons why a gulf-coast neighborhood might
flood for the first time, and it would not be at all unexpected for that
first time to come during one of the wettest and most destructive
hurricanes in Texas history.
Novak evidently could have been tasked with a more detailed
hydrological analysis, which might have provided some reliable evidence
demonstrating that the outflow from the Tenaris facility is what caused
these thirty properties to flood. Because he did not attempt that
analysis, we are left only with evidence that Tenaris’s defectively
designed facility caused some additional flooding in the area. The jury
must have believed that without the additional flooding attributable to
Tenaris, the plaintiffs’ flood damage would not have occurred. Perhaps
that belief would be proven accurate if we could obtain perfect
knowledge of the past. But our judgments must be based on evidence,
and on this evidentiary record, the belief that Tenaris caused the
flooding of the plaintiffs’ properties during Hurricane Harvey rests only
on speculation, not on evidence.

17
III.
For these reasons, the judgment of the court of appeals is
reversed, and judgment is rendered for the defendant on all claims.

James D. Blacklock
Chief Justice

OPINION DELIVERED: May 23, 2025

18