Related to this question a bit, the house I'm talking about was swallowed into another dimension along with parts of its garden. The house itself stays completely intact, but the piping is cut off, obviously.

I assume electricity will be gone immediately, but what about water? If you were to try and use the sinks, could you still get some water before it goes completely dry? Does the water get stored somewhere perhaps? And if yes, how much approximately?

I heard some countries have boilers in their bathroom that preheat the water before they can use it for their shower, as in, it's installed right in their bathrooms. Would those have some usable water for the residents?

Some additional info:

  • the house was previously in a quiet residential neighborhood
  • the dimension works pretty much exactly like our world in terms of physics, so you have regular gravity (and some air to breathe)
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    $\begingroup$ I think the question of "where" is more related to a location like "country". Depending on where they were originally, their utility setup will vary, and produce different results. $\endgroup$
    – Chris M.
    Sep 11, 2018 at 14:55
  • $\begingroup$ @ChrisM. I have nothing specific regarding that because I have this happen to places all over the world, so I need an answer that would apply in general. If that's not possible, then simply assume it's a house in one of the DACH countries. (Germany, Switzerland, Austria) $\endgroup$
    – user30310
    Sep 11, 2018 at 15:01
  • $\begingroup$ Since the new world looks like our world, you could of course hook up to the new world's municipal water system. Or, I don't know, dig a well or something. (This is a hint that your question is too broad.) $\endgroup$
    – Spencer
    Sep 12, 2018 at 2:41
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    $\begingroup$ I'm wondering if this is a plumbing question rather than Worldbuilding! Turn off the mains in your house, and you'll have your answer! Probably some of the taps will work but not others. $\endgroup$
    – komodosp
    Sep 12, 2018 at 8:29
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    $\begingroup$ @colmde if the pipes were cut then the water would leak out of them and there would be no pressure. No taps will work. $\endgroup$
    – Matt
    Sep 12, 2018 at 12:10

9 Answers 9


Its been pointed out a few times in the comments that local uses of words differ significantly,, apologies for any confusion on my part in that; I've edited this answer and tried to keep the working as open as possible to reduce any issues from this

Mains Pressure

Water Pressure comes from Mains pressure. This is generated by the house being lower in altitude then the water supply, either a large water tower water is pumped up to it and then gravity does the work of moving it to your homes. If you removed a house and its on-property pipes from the grid, the house itself would have a higher pressure within the pipes than the surrounding pipe-less environment so mains pressure wouldn't work. however as Josh King noted in the comments most municipalities require Back Flow Prevention Valves, meaning the water can only go into the house, stopping the risk of potentially contaminated water flowing from the house back into the mains. this would mean that some water would be stored in the pipes however it would be very tricky to access without a fair amount of plumbing knowledge.

Boilers or Hot Water Tank

A lot of houses that have the room have hot water boilers or hot water tanks. where water is heated and stored for the use in showers baths and the hot water tap. This is actually the norm in the UK: the boiler holds a large amount of water at about 60-80 degrees Celsius, which is then mixed with cold water to give the showers and baths some degree of temperature control. These tanks vary in size dramatically but usually are between 60 and 180 litres. the exceptions to this rule is in small properties and flats, where the space taken up by the equipment is at a premium. in those circumstances they often install heating elements that heat up the cold mains feed water as they pass to the shower or bath.

Expansion Tanks or Cold Water Storage

Some older houses have cold water expansion tanks which give the property pressure. This is common in locations where either the mains pressure is too low or too high: if it's too low, then water towers are installed as in L.Dutch's answer; if it's too high then an expansion tank is installed to offer a more regulated pressure. This was common in the UK about 20 years ago at least.


All toilets do have water cisterns for the flush. This is often about 5 litres. It may not seem like a huge amount but it can be drained without ever touching the toilet bowl, although I'd still recommend boiling and filtering before drinking.

Rain Collectors

It's also not uncommon these days for houses with gardens to collect rain water runoff from roofs into water butts, so this could be another source.

Heating System

There would also be water in radiators if fitted however this would not be safe for drinking, in theory however it could be made safe, easiest way to do this would be a reverse osmosis device if you happened to have one lying around, but apart from that this should not be considered useful water.

As an aside

Its also not unheard for houses to have Photo-voltaic Solar Panels on their roofs so power may still work... providing your world has a sun. It may not be common yet but it's a definite possibility.

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    $\begingroup$ Good summary. Also, most municipalities require back flow prevention valves at each residence, to prevent back contamination of the water supply. So the water won't leak out when the pipes are cut. Also many of these water sources won't just flow out of the tap (depending on plumbing elevations and gravity) and may require some basic plumbing knowledge to access. $\endgroup$
    – Josh King
    Sep 11, 2018 at 15:24
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    $\begingroup$ Many UK houses have a cold water tank in the loft (as well as an expansion tank -- that term is used in the hot water system for a much smaller tank). Mine only provides pressure for the stored hot water system, but in previous houses this has also fed the toilets and even the upstairs taps. The capacity could be up to around 400 litres. $\endgroup$
    – Chris H
    Sep 11, 2018 at 15:56
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    $\begingroup$ To add hot water boilers contain potable water in most of the world so you can get several days worth of drinking water out of it. It is actually a recommended survival action in cases of large scale disasters. $\endgroup$
    – John
    Sep 11, 2018 at 15:58
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    $\begingroup$ Unfortunately normal solar panel installations like you'd find on a typical home are unable to provide power when the grid goes down. I'm not sure of all the details but basically they'd need an extra piece of equipment to run independently, something expensive that only people building an apocalypse shelter or a house in a very remote location with no grid connection would pay for. A regular residential home would not have it. $\endgroup$
    – Jared K
    Sep 11, 2018 at 17:12
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    $\begingroup$ Note that in the UK "cold water tanks in the loft" and "boilers holding a large amount of water" are not the current "state of the art" in plumbing and heating systems, though of course many older houses still have them. Modern so-called "combi boilers" (which were first used more than 50 years ago!) and heating systems have no water storage, except for an very small amount of water to keep the heating system pressurised - and that small amount is inaccessible, and in any case undrinkable because it contains corrosion inhibitor additives! $\endgroup$
    – alephzero
    Sep 11, 2018 at 22:07

Gosh, this is really dependant on the house. My family owns a farm, and we have a well...and that answer would depend on how far DOWN the interdimensional rift goes, because the well is pretty close to the house, so it would be included, it's just a matter of how far down it goes.

A place in the country, or in a quirky neighborhood is more likely to have an alt water source, such as:

  • Rain Barrels off the gutters
  • onsite cistern (either in the ground in the case of residential or on the roof in the case of apartment buildings)
  • an actual well. Sometimes happens in a residential area that everyone else will be on city water, but your old house has a well and pump. The problem is that the pump needs electric to work most of the time (though there are some that have a crank pump for emergencies--these are mostly installed by paranoid folk or people who simply want to live off the grid or electric goes out often, or because the old pump wasn't hooked up to the new system, and this is a remnant of the old system.) Without electric, the pressurized tank will supply water for a little while. These tanks range from as little as 2 gallons (mostly for places that are using it for small watering needs, such as periodic watering of plants, while the rest is on city water) to as much as 114 gallons. The standard size tends to be about 20-40 gallons, but 80 gallons can be common. Varies widely!

I looked at the original question and frankly, if the house is just CUT away, including the plumbing, then there will be issues in OUR dimension.

See, mainlines can run through front yards, and then have lines off that, which means that in reality, where the house has disappeared from, there's bound to be problems. Even if things sync up exactly, a pipe can be several feet to the left or right if you cut out the middle where the house is, so it might not match up.

In other words, there's a plumbing problem everywhere....and outside of reality there's not enough pressure in the lines once they are effectively cut, to give you any water. Maybe for a second, but that's it. In the U.S. there's a water heater, and those sometimes have water stored in--depends on the size--they can be 80 gallons, they can be 25. About 50 is the average. Tapping it could be difficult depending on the system.

UNLESS--introducing interdimensional plumbing AND electric! You can't get wifi, (or maybe you CAN!) but you do get intermittent plumbing and electric. Anything with a hard line in or out works, kind of.

Because you're bending space-time, the house is really still there, it's just in a pocket dimension. Maybe nothing organic can get through, but objects and energy CAN. Which opens up a whole world of possibilities...

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    $\begingroup$ Actually -- tapping a tank-type HWH is relatively easy (just use the drain valve) $\endgroup$
    – Shalvenay
    Sep 11, 2018 at 15:37
  • $\begingroup$ Wells typically have an onsite electric pump, so even if your well comes with, the pump would not operate (unless you rig it up with a generator). I was on a Well Water system as a kid and we would loose water shortly after we loose power (you had enough for a few water uses, but not enough for long). When we moved to the city, Water was not dependent on power as it was delivered in pressurized mains and was power neutral... the only time you lose water was being on the wrong end of a water main break. $\endgroup$
    – hszmv
    Sep 11, 2018 at 16:02
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    $\begingroup$ When I was a kid, we also lived in a place with a well that had a large above-ground tank to pressurize and store water after it was pumped up from the ground. When we had electricity outages, the pump would no longer work, but we did have enough pressure to fill up several large containers before no water would come out of the faucets. The well tank also had a faucet at the bottom of it so that you could drain the tank almost all the way to the bottom using gravity if you had to. $\endgroup$ Sep 11, 2018 at 16:50
  • $\begingroup$ @Kevin Peter: Still works that way today, for a good many domestic wells in the US (including my house). $\endgroup$
    – jamesqf
    Sep 12, 2018 at 4:32
  • $\begingroup$ @KevinPeter Yes, without electric there's generally a bit of water, but that's dependant on the pressurized tank size. I'll edit my answer! $\endgroup$ Sep 13, 2018 at 4:03

It can be, yes. There are several cases in which water is not directly supplied from the outside.

  • Some houses have water tanks on their roof (see the example in the picture). Some are also used for solar heating.

water tank on roof

  • Some other have a small tank and a pump somewhere in the basement to act as a buffer and decouple the house piping from the supply pressure.

water tank with pump

  • Some other have a built in water collection room, where rain water is collected for later usage.

water cistern

In all the above examples, there would be no immediate disruption. Water will be available as long as the storage is not empty.


It's fairly common here (Ireland) to have a tank in the attic which feeds the upstairs water and the downstairs hot water tap. But the downstairs cold water tap, and the dishwasher/washing machine are fed from the mains.

Therefore you'd lose your downstairs cold & dishwasher/washing machine. You also wouldn't be able to refill the tank, so for upstairs you'd have whatever remains in the tank.


If the house gets it's water from a pipe connected to a main water line running under the street, then no.

If the house has a cistern on the side of the house fed by gutters, then yes the taps would work after you started up the gas generator you keep in the garage (since if you have a cistern, you're likely to be more self-reliant than most suburbanites and urbanites).


Header tanks should stay full after the mains are cut and the water still be readily accessible, it will gravity feed into the house. Most hot water cylinders will also stay full but getting the water out without the electric pump (either in the house or from the mains) will be more awkward due to the position of the dump valves.


Assuming you're looking for sources of water:

Where I live, most houses have central heating. (and a lot have boilers but that's already in another answer) The central heating is a closed system where the heat is transported with water. For water you could tap into that.

Also your toilet tank will have clean flushing water, about 7 liters of it. (I drilled in my water-pipes once. The knowledge that you have only 1 flush left...).

  • $\begingroup$ Central heating water gets quite gross (if you ever have to drain your CH system, the water comes out black) and is not potable. $\endgroup$
    – Hobbes
    Sep 12, 2018 at 12:24

I also have a well (50' deep, which is about the border between what is considered a deep vs shallow well). Water is pumped to a large (1500 gallons) storage tank. Then it is pumped to a large (80 gallons?) pressure tank. As others have said, the pressure tank works without electricity but it will not refill. The large storage tank can produce water with a bit of pressure, which will lessen as the tank empties.

I don't but a lot of people have generators or a backup battery system for the express purpose of running their well pumps in the case of a power outage.


My home has roughly 10,000 litres of water in tanks inside the building.

It depends on where the home is from. We rely on trucked water, thus the tanks.


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