Fire Hydrant Maintenance

​​The Central Otago District Council strives to ensure that all of the district's fire hydrants are in good working order at all times. It would be unacceptable in the event that ANY part of our water system should fail to work at any time.

Flushing fire hydrants may, at first glance, seem like a waste of water, but there are a number of things taking place during this exercise. We hope an explanation helps to ease any concerns you may have.

Hydrant flushing removes the sediments from the mains and also serves the following purposes:

  • Improves water quality in the distribution system;
  • Verifies the proper operation of fire hydrants and valves;
  • Helps find weaknesses in the water system;
  • Checks for closed valves and weak flows in the water mains;
  • Verifies adequate fire flows for firefighting.

Typically the Central Otago District Council will advertise the programme two weeks prior to starting. You can check out the following for notification when flushing will occur:

  • Our website
  • Local newspapers - particularly our CODC Noticeboard in the CO News
  • Our CODC Facebook page


What should I do when water services staff are flushing in the area?

If you see water services staff flushing a hydrant on your street, avoid running tap water and using the washing machine or the dishwasher until the flushing is completed.


What could I expect before and after flushing?

  • If tap water is used during flushing, it could come out discoloured and contain sediment. If you encounter discoloured water, shut the water off and wait several minutes. After waiting, check the clarity by running cold water for a few minutes allowing new water to work its way into your pipes. If the water is clear its ok to use. If not, wait a few more minutes and check again. In some cases, there might be slight discolouration for a few hours. This discolouration only affects the appearance of the water; it does not affect the taste or water quality.
  • The water may also have a milky appearance. This is due to tiny air bubbles and will dissipate out and is not harmful.
  • Avoid washing laundry during scheduled flushing times. Wait until the water runs clear at the tap, then wash a load of dark clothes first. Hot water cylinders can hold discoloured water for some time after the cold water clears.
  • There may be a temporary drop in water pressure. If pressure or volume remains low, check tap and mixer screens for trapped particles.
  • Flush your hot water cylinder by running the hot water tap for a few minutes after the cold water clears.
  • You may notice a more pronounced chlorine taste during flushing. This is because free chlorine has a more noticeable chlorine taste and odour. This will dissipate when water is left in an open container in the refrigerator. Letting water in a glass sit for a moment will also take care of air bubbles that are stirred up during flushing and cause the milky appearance.



For additional information about the flushing programme contact Tim Crook on (03) 440 0630.

Page reviewed: 08 Oct 2015 11:38am