I heard that if citizens don't use enough water, the infrastructure (tubes etc.) takes damage. In order to keep the tubes clean, government agencies flood them with huge amounts of water. Thereby "wasting" the water you tried to save.

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    I think this depends on the city. However, it's likely that if one tries to educate people to be liberal with water use, in the long run we will probably end up using way too much water (probably also in the countryside). I think that flooding pipes with water if and where necessary is probably the better choice. (Also, the flooding water need not be drinking water quality.) I hope someone will write a more insightful answer, so I'll leave it as a comment for now.
    – Earthliŋ
    Commented May 26, 2017 at 0:40
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    This is the first I've heard of this practice. Do you have any references?
    – LShaver
    Commented May 26, 2017 at 3:03
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    @LShaver Just to provide some reference, here is an article in German. Maybe using machine translation you can get the gist of it.
    – Earthliŋ
    Commented May 31, 2017 at 13:33
  • @LShaver (etc.) This is worth a read web.sbe.hw.ac.uk/staffprofiles/bdgsa/…
    – Chris H
    Commented Jun 26, 2017 at 12:41
  • Something like what you mention was a reason behind combining rainwater and foul water sewers in the past. It didn't work as well as later systems (see the link in my previous comment). The point of sewer flushing is that a lot of water goes down them fast. You can't make a noticeable difference to that however much water you use -- your connection is too small.
    – Chris H
    Commented Jun 26, 2017 at 12:56

1 Answer 1


It's possible that the source was talking about a practice called jetting that municipalities use to clean their sanitary sewer systems. I know one town that cleaned their system this way every other year.

  • This is also done to storm water pipes to ensure the pipes don't get blocked when they are really needed, such as after or during major rainfall events. Also, the potable water supply pipes to houses can sometimes be flushed to remove sediment that can accumulate in them occasionally, particularly if the water supply system is inundated with turbid water especially after or during a drought when the water catchments have no grass of vegetation to prevent run-off water carrying away sediment from catchment walls.
    – Fred
    Commented Jun 3, 2017 at 12:28
  • My city does this on schedule throughout. They use an overpowered power washer that can cut root intrusion and the flow also pushes other blockages to a catcher at the next manhole.
    – RomaH
    Commented Jun 14, 2017 at 18:17

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