# Why \*did\* the hydrants in LA run dry? **URL:** \ **Category:** Factual Questions\ **Tags:** trump\ **Created:** [January 23, 2025, 10:27pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309 "2025-01-23T22:27:41Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![WildaBeast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wildabeast/32/6_2.png) [@WildaBeast](https://boards.straightdope.com/u/WildaBeast)\ **Post date:** [January 23, 2025, 10:27pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/1 "2025-01-23T22:27:41Z")
I think we’ve all heard the news stories about fire hydrants in the LA running dry while fighting the wildfires there. Trump blamed it on Gov. Newsom refusing to send water from NorCal to the south, which I know has been debunked. But I’m curious as to what _was_ the problem. The reports I’ve heard said the hydrant system was designed for fighting structure fires and simply wasn’t up to the task of fighting a large wildfire. Does that mean the problem was the actual quantity of water in the system? Or water pressure, like if you open to many hydrants the pressure in the system drops? Or something else? ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [January 23, 2025, 10:42pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/2 "2025-01-23T22:42:23Z")
Water is an incompressible fluid. This means you can only push so much of it through a given diameter pipe at a time, and if you draw more than the system can deliver, the pressure drops precipitously, notwithstanding all of the compromised water lines going into houses that have burned down to the foundation and are leaking any water coming into them. Many of these older developments (which both Pacific Palisades and Altadena are) are already stressing the water systems just because of how built up they have become, and they certainly can’t deliver the vast quantities of water necessary to suppress a massive fire covering thousands of acres of flammable structures and foliage, notwithstanding that there is basically nothing firefighters can do to suppress a firestorm driven by gale-force winds. From an earlier thread: > [@LA valve Trump speaks of](https://boards.straightdope.com/t/la-valve-trump-speaks-of/1013291/7): > > It is also a fact that regardless of how much water is available in reservoirs and fire cisterns, the municipal water supplies (which are not controlled by the state) can only provide so much volume of water at a time before pressure drops cause the hydrants to run dry. Those systems are sized for typical residential and modest commercial use, and in the case of older neighborhoods are often already stressed by the amount of additional housing since they were originally installed. Relying on that system to provide water volume to fight a massive wind-driven firestorm is hopeless, notwithstanding that as houses burn to the ground their own water supply systems fail and release pressure. > > The City of San Francisco actually has an entirely separate [High Pressure Auxiliary Water Supply System specifically for fire service use](https://sf-fire.org/our-organization/division-support-services/water-supply-systems) because of the history the city has had with massive urban fires (most recently the 1906 earthquake and fire, but also the “Great Conflagration” in 1851 that burned most of the structures in the city to the ground). To install such a system in fire-threatened neighborhoods today would require digging up streets, sidewalks, and lawns at almost incalculable cost, and would still not prevent the kind of gale-force-wind-driven firestorms that consumed Pacific Palisades and Altadena. As for it somehow being Gavin Newsom’s fault, he doesn’t control municipal water supplies, has limited control over fire abatement measures at the municipal and county level, and CalFire only responds to events when they threaten to cross fire districts. Stranger ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [January 24, 2025, 10:18am UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/3 "2025-01-24T10:18:12Z")
Part of the problem is that when a house burns to the ground, its plumbing system ruptures and the pipes end up free-flowing. It’s not a major problem when it’s one or a few houses doing this, but when it’s _hundreds_ of burned down houses free-flowing, that’s a substantial burden on the system. In the **[Marshall Fire](https://en.wikipedia.org/wiki/Marshall_Fire)** about four years ago, city water workers were sent out with fire crews. Each time the crew deemed a burning house to be beyond saving, the water worker would close the valve at the street to shut off the supply to that house. This is believed to have been a key factor in maintaining the water supply’s ability to continue serving the firefighting effort for those houses that could still be saved. The other thing they did in the Marshall fire was to push untreated water into the system. It took some work afterwards to decontaminate the supply network, but this did help keep the water coming for the firefighting effort. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [January 24, 2025, 1:31pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/4 "2025-01-24T13:31:23Z")
I also wonder whether the system was designed to support a major fleet of pumper trucks all sucking from the hydrants at once. How many separate pumpers were active during the major part of the fire? I would be surprised if they did not mobilize almost all the ones in the area, and there was that deliberate disinformation about Oregon trucks that went to help, too. > [@Machine\_Elf](#): > > Part of the problem is that when a house burns to the ground, its plumbing system ruptures and the pipes end up free-flowing. I assumed this was a major issue too, and one that got barely any mention. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [January 24, 2025, 1:38pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/5 "2025-01-24T13:38:48Z")
> [@md-2000](#): > > I assumed this was a major issue too, and one that got barely any mention. Good article here about how city officials managed the water supply during the Marshall Fire: [https://www.9news.com/article/news/local/wildfire/marshall-fire/louisville-superior-water-supply-marshall-fire/73-e9c78aea-fec0-4bef-bdc0-e484bdf9df1a](https://www.9news.com/article/news/local/wildfire/marshall-fire/louisville-superior-water-supply-marshall-fire/73-e9c78aea-fec0-4bef-bdc0-e484bdf9df1a) ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [January 24, 2025, 2:48pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/6 "2025-01-24T14:48:49Z")
Sadly, I think of the US Army Air Force strategy for firebombing Japan, and how the bombloads always included high-explosive bombs along with the incendiaries in order to break up municipal water systems and make firefighting impossible. This type of catastrophic event is clearly beyond the design parameters of any municipal water system. The fire itself makes firefighting impossible unless extraordinary measures (like cutting off residential water) are taken. And even then, demand probably utterly outstrips supply. ---
**Author:** ![Pork\_Rind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pork_rind/32/111_2.png) [@Pork\_Rind](https://boards.straightdope.com/u/Pork_Rind)\ **Post date:** [January 24, 2025, 2:53pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/7 "2025-01-24T14:53:03Z")
> [@md-2000](#): > > I also wonder whether the system was designed to support a major fleet of pumper trucks all sucking from the hydrants at once. It was not. As pointed out, the system was barely sized to meet normal residential need. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [January 24, 2025, 7:26pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/8 "2025-01-24T19:26:25Z")
> [@gnoitall](#): > > This type of catastrophic event is clearly beyond the design parameters of any municipal water system. And that consistently is the problem with disaster planning. They don’t seem to actually plan for the disasters. Water pressure running low in a major fire event is a foreseeable problem. Major fire events hitting urban areas in California near and in the WUI were known to be of real risk _before_ this fire happened, and clearly are going forward. There is and was no possible way to plan ahead to mitigate the risk or to have better back up plans ready to implement? ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [January 24, 2025, 7:47pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/9 "2025-01-24T19:47:26Z")
Here’s the thing- that water in the hydrants is regular old water main water. That means that in Los Angeles’ case, it has to come down out of the mountains, flow through various aqueducts, get purified, then pumped into the city water mains. This all happens at a limited rate. Of course, there are reservoirs (I’d assume) both treated and untreated, and excess capacity within the distribution network and for the pumps themselves. But the thing is, if you take something like this and all of a sudden hook up dozens of pumper trucks pumping as fast as they can go and crank up your distribution pumps, there’s only _so_ much water in the system on this side of the purification plant, and those pumps can only move it so fast, and keep up so much pressure. And it’s localized too- that demand isn’t uniform across the distribution network either- it’s concentrated near the fires, so the pumps and distribution network nearest there would have to handle that demand. I suspect that the system is intended to supply what they expect to use in normal usage, with some sort of percentage cushion for things like fires, large scale leaks/pipe breaches, and the like. It’s like anything else- there are disasters you can plan for, and that are likely, and then there are ones that are not. City governments don’t have the money, and nor do state governments, to engineer systems to easily handle wildly extraordinary events like this, Hurricane Harvey, and so forth. That’s why abject failures like Hurricane Katrina and the Texas 2021 Winter Storm were so infuriating- those were absolutely predictable and preventable disasters. I’m not so sure these wildfires fall into the same category in terms of preparedness. > [@gnoitall](#): > > The fire itself makes firefighting impossible unless extraordinary measures (like cutting off residential water) are taken. And they can’t realistically “cut off residential water” as such. More likely they’d have to cut off water to whole swaths of the city at once, which depending on how they’re set up, may be someone clicking a mouse, or it may be a crew driving a truck around and manually closing valves. Certainly not a fast thing if it’s the latter. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [January 24, 2025, 7:58pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/10 "2025-01-24T19:58:40Z")
> [@DSeid](#): > > There is and was no possible way to plan ahead to mitigate the risk or to have better back up plans ready to implement? While I don’t want to suggest that politicians and officials have not failed to anticipate foreseeable disasters and adjust policy to try to avert or prepare for calamities such as these fires, the reality is that once a fire gets started under these conditions and grows so rapidly before any effective response can be rendered, it can be nearly impossible to even contain much less suppress. Suppression of a normal house fire takes somewhere beteen 500 and 2000 gallons of water per minute, and this was a case of thousands of structures combusting fed by gale-force winds and burning embers and debris. Having a more consistent water supply might have helped with containment or saved a few homes but once fire starts moving into a developed neighborhood with such speed and ferocity there is no real possibility of establishing firebreaks or eliminating fuel because the houses, their contents, and the foliage around them are fuel. We’ve had a surfeit of self-proclaimed experts spouting off in the last couple of weeks with ill-informed solutions such as making all homes “fireproof”, eliminating all foliage-bearing plants from neighborhoods, building and filling giant artificial reservoirs, demolishing all ‘burnable’ structures in urban wildland interface locations and prohibiting new building, making all new construction “multi-family homes” in city centers to be ‘away from’ the fire. The reality is that even if people actually wanted to live in concrete bunkers, would accept being forcibly relocated from historic neighborhoods into jammed up apartments, or would support massive earthworks projects to build new dams and reservoirs, it would be exorbitantly expensive, economically disruptive, and ultimately wouldn’t really solve the problem because Los Angeles and the surrounding communities are almost all in that urban wildland interface, and plowing over mountains and cutting down all trees and bushes would turn it into even more of a massive heat-island hellscape. If you want that, Phoenix is just a short flight away, although I suspect most residents share [Lucille Bluth’s sentiment on that matter](https://youtu.be/u59s9KuQ5RU?si=CUw087HJIbgFXBjR). The real failures in planning aren’t in somehow marshaling enough resources to somehow suppress giant firestorms, but to prevent them from happening in the first place. The Palisades fire is strongly suspected to be due to fireworks that created a smoldering on New Years Day; the Eaton fire that ate Altadena was almost certainly due to Southern California Edison not maintaining an appropriate firebreak below their lines and shutting off power when the high winds picked up (even though they swear they did both, there is copious evidence to the contrary); another fire at the west end of San Fernando Valley was suspected to have been started deliberately. Maintaining firebreaks and removing fuel, shutting off power or buying lines (where possible; not really feasible in the case of high voltage lines in the granite faces of the San Gabriels), stronger regulation and prohibition of fireworks sale and usage with severe penalties, and promoting fire-resistant construction methods and tax credits to compensate for implementing wildfire hardening measures on existing construction (although there is a limit to what can be done in the mostly pre-WWII neighborhoods of Altadena) are all better uses of time and effort than trying to make more water available or impose draconian measures to prohibit any combustable structures and foliage. Stranger ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [January 24, 2025, 8:10pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/11 "2025-01-24T20:10:44Z")
Remember the water issue was only for the Palisades fire, i.e Malibu. Eaton Fire and now the Hughes fire and many others had no water issues. Malibu uses an old out of date system, never planned for the population there. It wasnt that California didnt have enough water or even LA county didnt have enough water- it was just that Malibu’s system couldnt meet the demands. > [@Stranger\_On\_A\_Train](#): > > We’ve had a surfeit of self-proclaimed experts spouting off in the last couple of weeks with ill-informed solutions such as making all homes “fireproof”, eliminating all foliage-bearing plants from neighborhoods, building and filling giant artificial reservoirs, demolishing all ‘burnable’ structures in urban wildland interface locations and prohibiting new building, making all new construction “multi-family homes” in city centers to be ‘away from’ the fire. The reality is that even if people actually wanted to live in concrete bunkers, would accept being forcibly relocated from historic neighborhoods into jammed up apartments, or would support massive earthworks projects to build new dams and reservoirs, it would be exorbitantly expensive, economically disruptive, and ultimately wouldn’t really solve the problem because Los Angeles and the surrounding communities are almost all in that urban wildland interface, and plowing over mountains and cutting down all trees and bushes would turn it into even more of a massive heat-island hellscape. Very true. > [@bump](#): > > That means that in Los Angeles’ case, it has to come down out of the mountains, flow through various aqueducts, get purified, then pumped into the city water mains. There was no issue with water outside the Palisades fire. Nothing to do with LA water in general. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [January 24, 2025, 8:19pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/12 "2025-01-24T20:19:10Z")
> [@DrDeth](#): > > There was no issue with water outside the Palisades fire. Nothing to do with LA water in general. That’s what I was getting at with the part about it being localized; if you suddenly have a huge demand in one area, that part may not keep up with the right amount of pressure, even though the system as a whole is fine. That’s probably even more true out on the periphery of the system, versus hooking right up to a big main right near a pump station. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [January 24, 2025, 8:21pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/13 "2025-01-24T20:21:10Z")
> [@bump](#): > > That’s what I was getting at with the part about it being localized; if you suddenly have a huge demand in one area, that part may not keep up with the right amount of pressure, even though the system as a whole is fine. That’s probably even more true out on the periphery of the system, versus hooking right up to a big main right near a pump station. Okay, that is true. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [January 24, 2025, 8:27pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/14 "2025-01-24T20:27:38Z")
> [@DrDeth](#): > > Remember the water issue was only for the Palisades fire, i.e Malibu. Eaton Fire and now the Hughes fire and many others had no water issues. That is not true: > **['The hydrants up here are dead.' Radio traffic shows how LA firefighters lost...](https://www.npr.org/2025/01/18/nx-s1-5262563/radio-traffic-la-fires-first-responders-water-shortage)** > > NPR transcribed more than 2,000 hours of radio communications from the LA fires. The analysis shows hydrants going dry and first responders fighting fires despite scarce resources. > _Other parts of LA had already began to burn. The Eaton fire started that evening near Altadena, a neighborhood about an hour’s drive northeast of Pacific Palisades at the base of the Angeles National Forest. By the early morning on Wednesday, the water appeared to be running out there, too._ > > _“We are now on scene of a structure fire on Altadena,” radioed a firefighter just after midnight._ > > _“Copy that, LA. We do not have water,” responded another in the area._ > > _By 6 a.m. Wednesday, firefighters in that neighborhood were also mentioning problems with hydrants – just like they had earlier in Pacific Palisades._ > > _“We’re having some water supply issues,” said one Eaton firefighter. “Some of the hydrants are going dry.”_ Stranger ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [January 24, 2025, 8:29pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/15 "2025-01-24T20:29:14Z")
> [@Stranger\_On\_A\_Train](#): > > That is not true: Interesting, I had not read that. Thanks. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [January 24, 2025, 8:42pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/16 "2025-01-24T20:42:22Z")
> [@bump](#): > > absolutely predictable and preventable disasters. I’m not so sure these wildfires fall into the same category That’s the thing. Major wildfires hitting urban centers abutting and within the WUI was absolutely predictable. It was not a question of if, it was just when. And the risks are increasing every year. I get that the answers are not easily apparent and that the division of authority makes it more difficult. But this is not a oh there was no possible way to have foreseen this was a risk sort of circumstance. And going foreign it is certainly a known risk to plan on better both preventing and dealing with when it still occurs when prevention fails. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [January 24, 2025, 8:49pm UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/17 "2025-01-24T20:49:28Z")
> [@DSeid](#): > > Major wildfires hitting urban centers abutting and within the WUI was absolutely predictable. It was not a question of if, it was just when. And the risks are increasing every year. It was apparent enough that insurance companies were cancelling homeowner policies in these areas in months preceding the fires, and as vilified as they may be for doing that, it was clearly a smart fiscal decision, albeit not one that is going to save them from [massive payouts and changes to their home insurance model in order to remain viable](https://www.npr.org/2025/01/09/nx-s1-5252837/will-there-be-enough-money-to-pay-out-insurance-claims-from-the-la-wildfires). Stranger ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [January 25, 2025, 2:14am UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/18 "2025-01-25T02:14:48Z")
I was under the impression that so much water was drained from the elevated water tanks that the pumps could not replace it quickly enough. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [January 25, 2025, 2:31am UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/19 "2025-01-25T02:31:14Z")
Also remember that some infrastructure like water mains are decades if not a century old in spots. I assume city governments are not enthusiastic to spend money to upgrade what works for now, cconsidering the cost of digging up roads and re-laying larger pipe “just in case”. It’s always something that can be done later. Meanwhile, the number of houses and spread of development just feeds off of what was once an adequate pipe size. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [January 25, 2025, 6:59am UTC](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309/20 "2025-01-25T06:59:40Z")
> [@WildaBeast](#): > > Trump blamed it on Gov. Newsom refusing to send water from NorCal to the south, When I read that original report I got the idea he thought water flowed “downhill” from the north. [Next page](https://boards.straightdope.com/t/why-did-the-hydrants-in-la-run-dry/1013309.md?page=2)