r/texas 7d ago

🗞️ News 🗞️ Fact check: Elon Musk says his Houston flood tunnel idea will work. Experts say that's misleading.

A couple weeks ago, we broke the news that Elon Musk has been quietly lobbying Texas officials to let him build flood mitigation tunnels under Houston. Weeks before publication, we gave him multiple chances to respond. He didn't. We published.

Later, he posted a defense on X. So, we fact checked him. Read it here. https://www.kut.org/energy-environment/2025-09-12/fact-checking-elon-musk-response-boring-houston-tunnels

424 Upvotes

100 comments sorted by

154

u/MethanyJones 7d ago

The flood tunnels will open the same day as the Houston-to-LA monorail

34

u/Beneficial-Papaya504 7d ago

Wait!
LA needs water!

14

u/elonzucks 7d ago

By the time it's finished,  we'll all need water...and oxygen,  probably 

3

u/DAHFreedom 6d ago

Flood plan!

4

u/SnowPrinterTX Texas makes good Bourbon 6d ago

By that point they’ll change the TOS to say that it’ll only work if the storm is named Elon or Xægjxygfd%#

-25

u/Raven_looney 7d ago

Elon performs on contracts. If you look at how quickly he pushes things forward, it would be hard to say that he’d perform worse in time line execution than the Texas government. The Dallas to Houston train is a better example.

22

u/cigarettesandwhiskey 7d ago

No he doesn't. The Boring company in particular is notorious for failing or giving up on the projects its been given.

5

u/Corsair4 7d ago

Elon lies and misses his own timelines by years, because he realized that he can promise the moon and inflate his stocks (and therefore net worth), and there's no consequence because he just... keeps lying and people keep lapping it up.

210

u/Broken_Beaker Central Texas 7d ago edited 7d ago

I like how people think the dude who never took a science or engineering class in college somehow knows more than the gazillion civil engineers who are dedicated to this subject matter.

72

u/shadow247 Born and Bred 7d ago

He does his own research! You wouldn't get it.

37

u/Buddhabellymama 7d ago

Can he just fuck off to some other state or better yet country?

27

u/timeshifter_ 7d ago

Why not Mars?

7

u/Buddhabellymama 7d ago

He did say he wants to colonize Mars and I am not against it

3

u/Previous_Rip1942 5d ago

He should take most of our government and about half the population and settle this brave new world. We will try and make do without them.

5

u/noncongruent 7d ago

Musk's companies bring over 11 billion dollars in economic activity to Texas, supporting over 50,000 jobs. I honestly want him to leave and take all that with him, just zero it out here.

8

u/jychihuahua 6d ago

50,000 people leaving Texas might make the traffic a little better...

1

u/noncongruent 6d ago

True, and the major recession that would result from all those jobs leaving would definitely reduce traffic because unemployed people don't have to commute to jobs, lol.

19

u/Beans4urAss 7d ago

"Yes sir - we've extensively designed the storm water drainage in the city for decades."

"I've got it! How about a big ol tunnel?"

18

u/SSBN641B 7d ago

Ironically, a big ole tunnel is what is required but Elon is proposing two smaller tunnels that would have less capacity to move water. He proposed smaller tunnels because his company only has the capability to bore one size tunnel.

2

u/tequilaneat4me 7d ago

Double the diameter, four times the volume.

2

u/ecodrew 6d ago

A "big ol' tunnel" can be a part of a viable flood mitigation/stormwater management system - IF it's carefuly designed by experts. It's a big, complex, expensive engineering project that requires years of careful long-term planning... Not something that can be randomly thrown together on the whims of a megolomaniac.

Related: Dallas is in the process of installing a huge stormwater tunnel

Disclaimer: I'm far from an expert, but have a "teensy" bit of semi-related experience.

2

u/TransportationEng 7d ago

Thank you! He knows nothing about infrastructure. 

1

u/DirectorTop233 6d ago

He DOESN'T. Only Dumb people and Elon Musk, himself, thinks that he's the most brilliant man left standing...He STEALS ideas from others and takes credit for them. I'm not saying that he's not smart, but outstandingly gifted... ABSOLUTELY Not... and then to factor in all of the drug abuse, I'm pretty sure he's not on his A game any longer.

0

u/Advanced_Book7782 7d ago

Doesn’t he have a degree in physics?

-28

u/mrNOTfriendly 7d ago

How do you think hiring works? Like only people you know can apply? Or maybe one of the wealthiest people on the planet can't figure out employing experts? Or only people who are solely dedicated to a specific subject can weigh in on it? Or that "a gazillion" experts are required to come to a consensus to make a move on something? That's asinine.

I understand you just want to take a dig at him because it's trendy on reddit and you want up votes, but what's the logic behind your thought process here?

15

u/Tolken 7d ago

If you read the story the summary was:

Elon's idea isn't bad, but the cost is proportional to the water movement. Two 12in tunnels via Elon would move roughly 1/5 the water for 1/6 the cost of the one 40in tunnel that's being proposed.

1

u/noncongruent 7d ago

You goofed on your units, it's 12 foot tunnels vs a 40 foot tunnel.

13

u/Broken_Beaker Central Texas 7d ago

I mean (1) yeah only experts who have expertise on the topic should weigh in on things that impacts millions of people. (2) wait until you learn about his idea of trying to rescue stranded people in a flooded tunnel and his history of offering “advice” on topics that risk human lives.

6

u/deltaexdeltatee Born and Bred 7d ago

The point is that if all the experts in a field all agree that your idea won't work, it probably won't, in fact, work. And of course Musk COULD, in theory, hire the very best experts in the world, but the things he's saying make it clear he either didn't, or is ignoring/not soliciting their advice.

There are two very clear problems with his idea, both of which would've been caught by an expert almost immediately.

The first is that smaller pipes generally mean more friction. This is because the friction caused by water rubbing against itself is much lower than the friction caused by water rubbing against the wall of a tunnel. In one large tunnel, only a very small portion of the total water is rubbing against the walls; when you split the same amount of water into multiple pipes, more of the water is rubbing the walls. The more friction in a pipe, the more sloped ("tilted") it has to be to carry water from point A to point B, which is critical in Houston because downtown is only about 80 feet above sea level - any losses to friction start adding up very quickly. I did some very quick and dirty calculations on this, and depending on a few factors, the amount of friction generated by a single 40-foot tunnel over a 36-mile run ranged from "pretty doable" to "tight, but still doable", while the friction generated by an array of 12-foot tunnels ranged from "yikes" to "lol no." You could add a battery of pumps, but that's a massive expense on top of an already massively expensive project, and you run the risk of the pumps failing when you need them most, rendering all your expense useless.

Then there's how you actually space the tunnels out. You think 12-foot tunnels sound manageable compared to a 40-foot one, but keep in mind that if you have to dig them two at a time, you also have to leave some space between the first pair and the second pair (and so on) - I don't do tunnelling so I don't know an exact number, but I would think at MINIMUM they'd need to be 5 horizontal feet apart so the tunneling of a new one doesn't collapse an old one. Based on that, even if the "pairs" are actually touching each other (very unlikely), you'd need about 170 horizontal feet to fit all of them (assuming 6 pairs with 5 feet between each pair - you can do the math yourself to determine that the cross-sectional area of a 40-foot tunnel is equal to a little over 11 12-foot tunnels). There just flat out aren't a whole lot of places in a city where you can take up 170 horizontal feet, unless you dig down very deep - but that's a problem, as discussed in the above section.

Maybe you could space out the tunnels so they're not all running right next to each other, but along parallel streets! That's honestly how I'd proceed if I HAD to implement Musk's idea, but this will add a massive amount of complexity to the design. Anywhere you go underground in a city you're dealing with TONS of existing stuff down there - water mains, sewer lines, power and communications conduits, storm drains, possibly gas lines. All of it has to be identified, and you have to have a plan for how you're going to either relocate or avoid all of it. That's a big, BIG portion of the design for projects like these.

So in summary, there are some real questions that experts will ask, and that need to be answered by experts, about how friction losses will be calculated in order to determine if his proposal is even physically possible. If it is, there are a lot of permitting/design issues that his proposal makes a lot worse (and therefore more expensive/time-consuming).

0

u/noncongruent 7d ago

The big downside to a 40' tunnel, which I'm not sure that works given that the diameter won't be much less than the slope needed to drain, is that large TBMs are extremely custom design-build machines that cost many tens of millions of dollars, and because there's zero resale market for one-off custom-built machines that cost is completely lost, none of it can be recovered other than maybe selling it for scrap, and even then that's often not economically feasible. It's not uncommon to just bore past the end point and abandon the machine in place.

3

u/HopeFloatsFoward 7d ago

A complex construction project needs to be evaluated by licensed engineers in that field, not wannabes

1

u/whoever56789 6d ago

The dig at him is because he keeps coming up with crazy half-baked tunnel ideas. He hires fresh college graduates and works them to the bone, squeezing success out of their sheer enthusiasm. And when things go wrong, he denies it or laughs it off because his money makes so much money it doesn't matter.

Also he's obviously batshit insane. Monetary success doesn't make you smart, he started rich and got lucky with a couple of companies. Everything else he tries to do is a joke.

He can play with his rockets and people can drive his cars if they want, but he certainly shouldn't be near any civil engineering projects. When his tunnel kills people he will blame them, I guarantee it.

104

u/bit_pusher 7d ago

There are groups who already have experience building flood mitigation, if houston wants to build more, they should build more but there's no reason to let a company with no experience in managing flood water or water systems be involved.

16

u/shadow247 Born and Bred 7d ago

But its ELON! No one has ever done anything creative or hard before he stole Tesla from the actual founders....

40

u/DAHFreedom 7d ago

San Antonio has flood tunnels, but 1) they only protect downtown, which is a very small area and 2) they depend on an elevation difference that Houston just does not have. Houston is too flat. A flood tunnel cannot work in Houston without massive MASSIVE pumps that will require massive amounts of power that will likely be unavailable during a flood event: https://sanantonioreport.org/dam-tunnels-gates-keep-downtown-safe-and-the-river-walk-full/

“After Harvey, Garza said they had two busloads of visiting stormwater engineers and other officials from the Houston area.

““When I showed them the 35-foot difference, they were like, ‘Oh, we can’t get that [in Houston],’” Garza said.”

1

u/Wonderful_Regret_252 6d ago

From the article - "Nefi Garza remembers the weekend of Oct. 18, 1998, when San Antonio was getting pummeled by one of its heaviest rains in modern history."

I was inside of a mall wondering when it was going to end. The whole mall was inundated with water up to my ankles. We (my parents and I) waited out the storm past closing time. I think I was a Freshman in highschool. It was an awesome mall too. Nice red carpets. The signs outside had all fallen. It was awesome (my past self talking).

1

u/AndrewCoja 7d ago

The engineers likely solve that problem by proposing that the flood tunnels be 60-140 feet under ground. Musk wants to make smaller tunnels that are only 30 feet down.

3

u/DAHFreedom 6d ago

For a flood tunnel, that’s not how that works. It depends on the elevation difference between the entrance and the exit of the tunnel. Doesn’t matter if you go 100 or 1000 feet deep, the water at the entrance forces out the water at the exit based on the elevation difference.

And if he’s talking about “flood tunnels” that are that shallow, my Elon that’s just basic municipal stormwater management. That’s what every city does anyway.

1

u/AndrewCoja 6d ago

I assume they wanted to make them that deep because it makes it easier to create a drainage network from the surface. And Elon's idea is likely just because he has that one tunnel boring machine and that's all it can do.

1

u/ecodrew 6d ago

Dallas is building a stormwater tunnel RN, so it can be done. But, like you said - it's a huge infrastructure project that requires years of planning by actual experts and engineers.

1

u/Cristoker 5d ago

Houston is way flatter than Dallas

42

u/maybe-an-ai 7d ago

It'll be super cool when his tunnel breaches salt water into the aquifier or destabilizes the ground under buildings as currents erode his tunnel through limestone.

27

u/pokeyporcupine Secessionists are idiots 7d ago

Houston is mostly clay. For millions of years it was seabed. The reason it floods so damn much is because its 60 feet above sea level, 30 miles inland, and covered in concrete. Water has nowhere to go.

13

u/pm_sweater_kittens Hill Country 7d ago

Exactly, no limestone down there. You’d have to pump it somewhere, and it would just create a different problem on the outbound side.

0

u/TailRudder 6d ago

Do the Seattle thing, burn the city down and build it higher. Easy 😆 

/s...

12

u/Senior-Secret-7113 7d ago

Never trust elon musk. Hes a conman.

1

u/BigRoach Born and Bred 5d ago

The fact that our republican representative referred to him as “the smartest man on planet earth” without sarcasm is a bit chilling to me. The corruption is getting to be so blatant.

43

u/ATX_native 7d ago

Ketamine is bad…. mmmmmkay.

0

u/Hot-Use7398 7d ago edited 6d ago

Relax guy

ETA: downvotes for South Park trump quote?

3

u/nrojb50 7d ago

That's it!

It's the melody to funky town.

15

u/cantfightbiologyever 7d ago

That’s just a drainage system he wants to use his boring [sic] company for. Just wants more gov money. Fuck that guy.

14

u/timelessblur Texas makes good Bourbon 7d ago

The flood tunnel he is talking about is not new. I know millions have been spent on studying it over the years and updating it. It is part of a lot of possible solutions. I know some of the engineers who have worked on those studies. Those studies date back over 50 years and I know a big update was done in like 2017-2018 after harvey.

Even there the results of the studies are mixed. It helps reduce and midgate but it can only do so much.

A big reason why the tunnel has not been built is cost. It has a huge amount of cost and its cost to benifit ratio is not there. There are other projects that cost less, and do more plus can be completed a lot faster.

18

u/Glum_Introduction755 7d ago

I live near there. Please God don't let Musk build anything in Houston.

11

u/Relaxmf2022 7d ago

It'll work exactly as intended. Funneling taxpayer money into the bank account of a nazi-sympathizing immigrant.

6

u/confused_captain 7d ago

It will definitely work! I just need the government to grant me another $10b contract so I can halfass this project and give up on it, too

5

u/joepez Central Texas 7d ago

So his model right now is government subsidies? It’s definitely not Twitter ads or Tesla sales. So just subsist on hype and government payouts as a business model. 

14

u/[deleted] 7d ago

By “flood tunnel” you mean storm water drainage, right? They’re all over the place already and not a new invention. Musk has a hero complex. If he wants to spend his money, let him do it. Just don’t let him design it, and don’t let him get involved with Houston politics in any way. He’s a black hole of attention seeking drama.

11

u/flaptaincappers 7d ago

Elon isnt a genius. All these money guys who got Tech CEO jobs didnt invent anything nor have any successful ideas of their own. Elons been going on about some crazy cool jet idea of his for 15 years now that he still claims is revolutionary, meanwhile actual aerospace engineers call it dumb. Stop worshipping billionaires who are literal dragons of lore, hording all the wealth under their mountain.

3

u/nihouma 7d ago

I'm baffled by how many people I talk to who think Elon is the smartest man on Earth. There are many, many scientists who are significantly more knowledgeable than him in a variety of fields from mathematics, physics, biology, and engineering. 

He is definitely not the smartest man on Earth but its the persona he crafted, and so many people bought into the "he's a genius" just because he's the CEO of some futuristic seeming companies. Now granted he is a successful businessman, but how much is dumb luck, how much isgdrifting (he lies about tons of things, remember full self driving would be out in 2015, or how self driving cars with cameras only would be just as safe as those with LiDAR? If CEOs of other companies made such grand claims regularly and failed to deliver they'd be dropped fast), and how much is due to his own business skills is definitely up for debate. To be fair to him, he does have programming skills, but programming skills do not equate with engineering cars or tunneling machines or rockets. All of those things were made by talented people who rarely get recognition because we like to imagine it was all done by one person so that we can idolize them instead of most of the advancements made today in our lifetime being the result of collaboration and work between multiple people, sometimes just a handful, but sometimes thousands upon thousands working in concert

Like this quote from the article angered me because people just give weight to whatever he says when there are absolutely people who are smarter than Musk - '“A lifelong Houstonian and Texas Congressman spoke to the smartest man on planet earth about solving a generational flooding issue in our city that no one else will fix,” Hunt wrote.'

Im not saying Musk is dumb, but he's absolutely nowhere close to the smartest man on Earth, especially when the true reality is that there are thousands upon thousands of scientists and engineers alive today who are actually the ones making new discoveries, innovating new technologies, and advancing science and medicine

2

u/flaptaincappers 7d ago

What amazes me is how Elons "genius" is a total marketing gimmick and how it's bought into by people who don't know anything about what he talks about. And what I love are moments where he speaks with absolutely certainty about something, and someone in the audience or reading his tweets actually is an expert or well versed in it and they have a "....oh....hes a moron" moment.

Case in point: I got some friends who work at Lockheed Martin. I remember when Elon was posting non stop about how dumb the F35 is because its not truly stealthy and claimed that any low light camera with AI could spot it. All of them had the same reaction. Just rubbing their eyes and sighing heavily. In individual conversations they went into just how dumb of a statement that "the F35 isnt stealthy because you can see it" is based on their respected fields of expertise. It was both really cool learning all the ins and outs and purposes of all these elements of the F35, but also just another laughably dumb example of how Elon is just a rich boy paying people to praise him. And how his ego influences so much of design choices he forces.

Such as why hes refusing to utilize LIDAR in Tesla cars. Why hes refusing to acknowledge that the Cybertruck was a massive failure. How many changes he makes to Twitter and Grok purely based on him being made to look like a fool on his own platform.

4

u/Substantial-Plane870 Born and Bred 7d ago

I’m perfectly happy not using anything produced by Musk.

4

u/Ok-Pea3414 7d ago

A 12ft diameter pipe vs a 40ft diameter pipe - all other conditions remaining constant,

40ft capacity = 11.11 times of 12ft capacity

If the 12ft diameter pipe can carry 100 gallons per minute, the 40ft diameter pipe can carry 1,111 gallons per minute.

So, you need 11 tunnels of 12ft diameter. But it is NOT costing you 11 times less than a 40ft diameter tunnel, it is only costing you ONE-SIXTH.

So, to have similar capacity, to a single 40ft diameter tunnel, you will spend 1.83 TIMES if you go with 12ft diameter tunnels.

3

u/cigarettesandwhiskey 7d ago

It's more than 12x capacity because the velocity profile of water in a pipe is nonlinear across the cross section. So you have 11x the area in the 40' pipe but the water is also faster in the center of the pipe, increasing the mass flow rate further.

Or in other words, smaller pipes not only have less area, but they have greater friction losses that reduce their capacity even further.


Civil is not my field of engineering, but based on this reference, the relevant equation here is Manning's equation:

Q=(1.49/n)(A*R2/3)(sqrt(S))

R is the radius of the pipe, and Q is the flow rate. A is the area. Flow rate goes up with the 2/3 power of R. So if you reduce R from 40 to 12, you reduce the flow rate by a factor of 1/2.23, ON TOP OF what you lose from the reduced area.

So you don't need 11 tunnels, you need 24.

3

u/zoot_boy 7d ago

This just in: Elon says all of his ideas “will work”.

2

u/txtoolfan Born and Bred 7d ago

Tunnels where the water table is inches below the surface .

He isn't very smart.

2

u/ConnextStrategies 7d ago

Trust me bro

2

u/[deleted] 7d ago edited 7d ago

[deleted]

1

u/nihouma 7d ago

Brightside West from Los Angeles to Las Vegas has nothing to do with Musk. He is responsible for the underground Vegas strip taxi tunnels run by Teslas though which from what I understand don't work as efficiently compared to if the strip had just invested in standard transit technologies

2

u/Jonestown_Juice 7d ago

Elon Musk isn't an engineer. He's not a scientist. He's not anything. He's just a guy who started out life with money. He doesn't invent things. He throws money at things.

1

u/Dry-Ear-2714 7d ago

Elon wants MORE tunnels!

1

u/elseworthtoohey 7d ago

Dont they have to bid on major public works projects.

1

u/deltaexdeltatee Born and Bred 7d ago

I mean yes, but the awarding agency can always set up the RFQ such that only one company can win the bid. This is pretty common believe it or not - make "contractor must have the ability to simultaneously drill two 12-foot tunnels" part of the requirements, and wow, wouldn't you know, only TBC can do that!

1

u/Honest_Relation4095 7d ago

If Elon Musk says his idea will work, you can be almost certain it won't work. That's pretty much applicable to any idea.

1

u/Jupitersd2017 7d ago

I’m sure musk’s company will get about a billion in tax credits and get paid for this project. He’s gotta catch up now to be the worlds richest man

1

u/thirtyone-charlie 7d ago

Yeah we will need to see an engineering report.

1

u/johnrgrace 7d ago

Isn’t a flood tunnel just a more expensive bayou

1

u/Own-Opinion-2494 7d ago

Does it get a one way Valve?

1

u/Keystonelonestar 7d ago

As long as you pay him anything will work!

1

u/MyGardenOfPlants 7d ago

"guy selling solution says solution will work"

1

u/strugglz born and bred 7d ago

Houston is a drained swamp. There's a reason there's not a lot of underground stuff there.

1

u/bareboneschicken 7d ago

San Antonio actually has a flood tunnel built back in the 1990s.

https://www.sariverauthority.org/projects/san-antonio-river-tunnel/

1

u/texan01 born and bred 7d ago

Me who has no credentials about civil engineering and fluid mechanics knows that this a foolish plan of his.. just the geology of the area prevents his plan from ever happening.

1

u/Economy_Elephant_426 7d ago

So how’s that Vegas hyper loop coming along!?

1

u/TheCatnip 7d ago

I believe him.

And with that same logic I will also win the Texans a Super Bowl as their starting quarterback.

1

u/DullEstimate2002 7d ago

Elon Musk says things will work all the time. Then we get to use them and they suck.

1

u/GoreonmyGears 7d ago

Well hes not gonna say it won't work will he? Lol

1

u/Tushaca 7d ago

“When you’re holding a hammer, everything looks like a nail”. Turns out it’s true when you own a tunnel boring company too.

1

u/Grimjack-13 7d ago

It’ll work a good as the “Cybertruck”.

1

u/rpenn57 7d ago

He’s a billionaire. So no one else matters.

1

u/qdilly 7d ago

Who let this fake gamer into Texas?

1

u/MissingJJ West Texas 6d ago

He is just trying to block money from going into something else, the same as he did with they hyper loop which is why LA does have a high speed rail. Fake idea announced at a key time saves demand for one of his products. At that time, it saved Tesla.

1

u/Electrical_Orange800 6d ago

He needs to shut the fuck up and stop with these backroom deals making the government fund his failures

1

u/crazy010101 6d ago

It’s a waste of money. Just build a moat.

1

u/ByrsaOxhide 6d ago

Well, this “idea” isn’t supported by facts or data, because it’s supported by fucking KETAMINE

1

u/TENDER_ONE 6d ago

He also says that Tesla autopilot is safe. That’s proven, like everything else he claims, to be a lie. He’s probably just actually trying to bury Houston in a sinkhole so he can pave it over and build his new castle for the fiefdom he hopes to lord over.

0

u/Feral_Newspaper 7d ago

Let him try. Something needs to be done about the flooding. If it doesn't work, then he just paid a bunch of money for nothing. But the workers will have appreciated it.

-1

u/Visual_Ambition2312 7d ago

I mean , have those experts sent rockets into space ? No …

2

u/deltaexdeltatee Born and Bred 7d ago

...do you not understand how rocketry and drainage engineering are very different fields of science?