# Water Towers **URL:** \ **Category:** Factual Questions\ **Created:** [December 26, 2000, 9:01pm UTC](https://boards.straightdope.com/t/water-towers/47286 "2000-12-26T21:01:25Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![N\_Cognito](https://avatars.discourse-cdn.com/v4/letter/n/97f17d/32.png) [@N\_Cognito](https://boards.straightdope.com/u/N_Cognito)\ **Post date:** [December 26, 2000, 9:01pm UTC](https://boards.straightdope.com/t/water-towers/47286/1 "2000-12-26T21:01:25Z")
How do they keep water from freezing during the Winter in water towers? ---
**Author:** ![Scupper](https://avatars.discourse-cdn.com/v4/letter/s/b9bd4f/32.png) [@Scupper](https://boards.straightdope.com/u/Scupper)\ **Post date:** [December 26, 2000, 9:05pm UTC](https://boards.straightdope.com/t/water-towers/47286/2 "2000-12-26T21:05:09Z")
And how do they get water in them in the first place? If you have enough pressure to get water all the way to the top of a building, why not just pressurize the building’s plumbing? ---
**Author:** ![casdave](https://avatars.discourse-cdn.com/v4/letter/c/c6cbf5/32.png) [@casdave](https://boards.straightdope.com/u/casdave)\ **Post date:** [December 26, 2000, 9:09pm UTC](https://boards.straightdope.com/t/water-towers/47286/3 "2000-12-26T21:09:59Z")
**Scupper** You serious or pulling my leg ? ---
**Author:** ![JeffB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeffb/32/188_2.png) [@JeffB](https://boards.straightdope.com/u/JeffB)\ **Post date:** [December 26, 2000, 9:14pm UTC](https://boards.straightdope.com/t/water-towers/47286/4 "2000-12-26T21:14:36Z")
**Scupper** , if you’re not pulling **casdave** ’s leg, try this link for [How Water Towers Work](http://www.howstuffworks.com/water.htm). As to why the water doesn’t freeze, I’m guessing they keep the water temp above 32 degrees. ---
**Author:** ![Scupper](https://avatars.discourse-cdn.com/v4/letter/s/b9bd4f/32.png) [@Scupper](https://boards.straightdope.com/u/Scupper)\ **Post date:** [December 26, 2000, 9:16pm UTC](https://boards.straightdope.com/t/water-towers/47286/5 "2000-12-26T21:16:48Z")
Casdave: Well, I never really thought about it. Jeez, make me feel bad, why dontcha? ---
**Author:** ![Scupper](https://avatars.discourse-cdn.com/v4/letter/s/b9bd4f/32.png) [@Scupper](https://boards.straightdope.com/u/Scupper)\ **Post date:** [December 26, 2000, 9:20pm UTC](https://boards.straightdope.com/t/water-towers/47286/6 "2000-12-26T21:20:18Z")
Okay, I read that article, now I understand and feel like a better person. For the record, I don’t think that the answer was so obvious that I should feel like an idiot for not knowing it. Also for the record, doesn’t the “big peach” water tower in that article look like a gigantic bare ass? ---
**Author:** ![JeffB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeffb/32/188_2.png) [@JeffB](https://boards.straightdope.com/u/JeffB)\ **Post date:** [December 26, 2000, 9:25pm UTC](https://boards.straightdope.com/t/water-towers/47286/7 "2000-12-26T21:25:13Z")
Yeah, it does look like a big ass. Here’s another site with [unusual water towers](http://members.tripod.com/~watertowers/). FTR, I didn’t think your question was obvious. I’m still curious about the OP and exactly how they keep the water from freezing. I’m guessing, without any direct knowledge whatsoever, that it’s a combination of insulating structure and heating systems. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [December 26, 2000, 9:34pm UTC](https://boards.straightdope.com/t/water-towers/47286/8 "2000-12-26T21:34:19Z")
I’d WAG that the water doesn’t freeze for two reasons: 1. It’s constantly in motion, being replenished as it’s used up. Water in motion doesn’t freeze as easily. 2. It’s not staying up there long enough to freeze; it takes a lake days of subzero temps to freeze, and there’s only a day’s worth of water up there, so it’d run dry before it froze. Fun cold-weather trivia question #2: Does anybody out there know why the water doesn’t freeze in fire hydrants? ---
**Author:** ![JeffB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeffb/32/188_2.png) [@JeffB](https://boards.straightdope.com/u/JeffB)\ **Post date:** [December 26, 2000, 9:48pm UTC](https://boards.straightdope.com/t/water-towers/47286/9 "2000-12-26T21:48:09Z")
Most fire hydrants in the U.S. are a dry-barrell type, meaning water is not stored in the above-ground portion. Since the water is underground, the temperature remains above freezing. There are also wet-barrell hydrants, which are used only in southern California. ---
**Author:** ![N\_Cognito](https://avatars.discourse-cdn.com/v4/letter/n/97f17d/32.png) [@N\_Cognito](https://boards.straightdope.com/u/N_Cognito)\ **Post date:** [December 26, 2000, 9:58pm UTC](https://boards.straightdope.com/t/water-towers/47286/10 "2000-12-26T21:58:55Z")
That link to How Stuff Works was interesting, but _didn’t answer the question!_ ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [December 27, 2000, 12:12am UTC](https://boards.straightdope.com/t/water-towers/47286/11 "2000-12-27T00:12:43Z")
**Ethilrist** answered your question: moving water doesn’t freeze. The water in a water tower is in constant motion. Water is pumped out as people flush toilets and wash dishes; more water is pumped in from the water treatment plant. ---
**Author:** ![JeffB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeffb/32/188_2.png) [@JeffB](https://boards.straightdope.com/u/JeffB)\ **Post date:** [December 27, 2000, 2:57pm UTC](https://boards.straightdope.com/t/water-towers/47286/12 "2000-12-27T14:57:13Z")
> [@](#): > > \*Originally posted by Duck Duck Goose \* > **Ethilrist answered your question: moving water doesn’t freeze. The water in a water tower is in constant motion. Water is pumped out as people flush toilets and wash dishes; more water is pumped in from the water treatment plant.** I wonder about this. Moving water does freeze, just not a easily, depending on its speed. I question whether the movement cause by usage would be enough to prevent freezing in places like Minnesota. ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [December 27, 2000, 3:17pm UTC](https://boards.straightdope.com/t/water-towers/47286/13 "2000-12-27T15:17:46Z")
I think “moving water doesn’t freeze” is a misunderstanding. “Frozen water doesn’t move” would be more accurate. Moving water isn’t frozen because, as you can tell from its liquid state, it’s not cold enough yet to freeze. I think the other answer must be right - the water in a tower isn’t there long enough to freeze. There is typically only a day or two of water, and the water would take longer than that. Remember, you have to extract a lot of heat to freeze water - the latent heat is 80 cal/g. If you have a vessel of water and you extract heat energy from it at a rate that its temp will change by 1 degree C per minute, it will go from room temp to the freezing poing in about 20 minutes, but will then take 80 more minutes to freeze (without the temperature changing at all). ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [December 27, 2000, 3:46pm UTC](https://boards.straightdope.com/t/water-towers/47286/14 "2000-12-27T15:46:43Z")
Okay, I stand partially corrected. [http://www.hebronindiana.com/archives.htm](http://www.hebronindiana.com/archives.htm) > [@](#): > > Moving water does not freeze at 32°. It depends on the speed of the water, but moving water’s freezing point is below 32. [http://www.boston.com/globe/search/realestate/hotton/plumbing.htm](http://www.boston.com/globe/search/realestate/hotton/plumbing.htm) > [@](#): > > So now’s the time to do something about keeping susceptible pipes from freezing. Turning the water on to a trickle during a heavy freeze will keep the water moving, and moving water takes longer to freeze than still water. [http://www.misshomes.com/news/forcesofnature.html](http://www.misshomes.com/news/forcesofnature.html) > [@](#): > > To prevent frozen pipes, the cold water should be allowed to drip very slowly to keep water flowing because moving water will not freeze as fast as water that is sitting still inside the pipes. But still, the water inside the water tower is moving, so it doesn’t freeze. And there’s this. [http://www.newton.dep.anl.gov/askasci/gen99/gen99700.htm](http://www.newton.dep.anl.gov/askasci/gen99/gen99700.htm) in which someone asks, “Does water in a water tower freeze?” And the Ask-A-Scientist guy says, “Not usually…it is moving and exchanging too much.” And there’s the Grand Rapids, Minnesota, water tower. [http://www.pce.com/water/grandrapids\_watertower.html](http://www.pce.com/water/grandrapids_watertower.html) > [@](#): > > The tower design included an insulated riser pipe to avoid pipe freezup during extreme Minnesota winters. Special consideration was also given to the pump station operation to promote water circulation to prevent icing conditions in the tank. ---
**Author:** ![JeffB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeffb/32/188_2.png) [@JeffB](https://boards.straightdope.com/u/JeffB)\ **Post date:** [December 27, 2000, 6:31pm UTC](https://boards.straightdope.com/t/water-towers/47286/15 "2000-12-27T18:31:01Z")
I stand completely corrected – it seems that there is enough movement to keep the water from freezing. On an unrelated note: > [@](#): > > To prevent frozen pipes, the cold water should be allowed to drip very slowly to keep water flowing because moving water will not freeze as fast as water that is sitting still inside the pipes. I once lived in an older row home in Philadelphia. The drain pipe from the second floor ran _outside_ the house. One winter, my toilet was running every now and again, causing water to drip down the drain pipe, which eventually froze. They had to use a blow torch to unfreeze it. It just goes to show that normally correct advise can sometimes result in the opposite happening. ---
**Author:** ![casdave](https://avatars.discourse-cdn.com/v4/letter/c/c6cbf5/32.png) [@casdave](https://boards.straightdope.com/u/casdave)\ **Post date:** [December 27, 2000, 6:46pm UTC](https://boards.straightdope.com/t/water-towers/47286/16 "2000-12-27T18:46:57Z")
**Scupper** Don’t take it so hard, I was just funnin 🙂 Actually that link was pretty good, I’m glad you asked. ---
**Author:** ![N\_Cognito](https://avatars.discourse-cdn.com/v4/letter/n/97f17d/32.png) [@N\_Cognito](https://boards.straightdope.com/u/N_Cognito)\ **Post date:** [December 27, 2000, 7:12pm UTC](https://boards.straightdope.com/t/water-towers/47286/17 "2000-12-27T19:12:05Z")
All of the responses so far have touched on the fact that _moving_ water tends to freeze at a lower temperature than 32F. Yeah, I’ll admit that the water in a tower moves around quite a bit and probably never freezes and bursts the tower. But let’s get a little theoretical now. Suppose I have a _very_ long pipe ( say 1" in diameter) filled with water going through it at 1 gallon/minute and initially the temperature is just above 32F. Now let’s cool the pipe to below 32F. Will the water eventually freeze in the pipe? Will it freeze first on the walls of the pipe where the water might not be moving as fast? Serious replies only, preferably from physicists. ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [December 27, 2000, 9:07pm UTC](https://boards.straightdope.com/t/water-towers/47286/18 "2000-12-27T21:07:08Z")
> [@](#): > > \*Originally posted by N\_Cognito \* > **But let’s get a little theoretical now. Suppose I have a _very_ long pipe ( say 1" in diameter) filled with water going through it at 1 gallon/minute and initially the temperature is just above 32F. Now let’s cool the pipe to below 32F. Will the water eventually freeze in the pipe? Will it freeze first on the walls of the pipe where the water might not be moving as fast?** Depending on the length of the pipe, as far as I can tell from my fluid dynamics and thermo and heat transfer, and heat exchanger design references from ASHRAE, yes, it will freeze. But your question is open-ended. How cool is it below 32 F? How long is the pipe? These are critical variables. And yes, the freezing should start on the walls, where the boundary layer is least turbulent. > [@](#): > > \*\*Serious replies only, preferably from physicists. \*\* I guess us Mechanical Engineers don’t qualify then. :rolleyes: ---
**Author:** ![honkytonkwillie](https://avatars.discourse-cdn.com/v4/letter/h/3da27b/32.png) [@honkytonkwillie](https://boards.straightdope.com/u/honkytonkwillie)\ **Post date:** [December 28, 2000, 9:28am UTC](https://boards.straightdope.com/t/water-towers/47286/19 "2000-12-28T09:28:42Z")
I work for the local water utility, and where I live freezing is a problem. We don’t have water towers in the usual sense, but about 30 above-ground “reservoirs” in the form of large tanks spread out through the distribution system. These tanks are made from steel or reinforced concrete, and range from 100,000 gallons to 2.5 million gallons. And we rely on the continuous raising and lowering of the water level inside to keep it from freezing. Yet, some reservoirs still get several inches of ice to form on the surface of the water inside. So they try to increase water utilization from those problematic reservoirs to get more turbulence going. Also, we have a means of adding heat to the water as it enters the distribution system, although it’s not been used for the last few years (I don’t know why). One of the water treatment plants is located right next to a natural gas fired power plant, and a heat recovery system was built snatch heat from the turbine-cooling water and warm up the water in the distribution system. ---
**Author:** ![Quasimodem](https://avatars.discourse-cdn.com/v4/letter/q/e274bd/32.png) [@Quasimodem](https://boards.straightdope.com/u/Quasimodem)\ **Post date:** [December 28, 2000, 10:26am UTC](https://boards.straightdope.com/t/water-towers/47286/20 "2000-12-28T10:26:42Z")
Also for the record, doesn’t the “big peach” water tower in that article look like a gigantic bare ass? \*\* [/QUOTE] Yeah, and then there’s that little “protrusion” at the bottom! Q