Back Flow Prevention

Protecting your Drinking Water

The Council is committed to supplying water which is safe to drink and we have a range of treatment systems to eliminate microbiological contamination and minimise risk to health. There is potential for every property to contaminate the water supply reticulation by backflow.

What is backflow? Backflow is when water flows in reverse to the normal direction ie from your place into the water mains.

Could this be happening at your place?

Common Causes

  • The most common cause of backflow at a house is the garden hose if it is left running in a puddle or underwater it can take the water back into the water main.
  • Another common cause of backflow is a bore pump accidentally connected to the public water supply via the house pipes.
  • Low pressure in the water mains caused by very high demands eg fire fighting or burst mains could allow contaminated water to enter the watermains.

Example of backflow:-

A house in Timaru has a leaking garden tap. Instead of fixing the tap the hose is taken from the tap into the sewer, if the water supply is shut off at the main for any reason, back siphonage could occur.

Legal requirements for backflow

If you have a private bore or a domestic irrigation scheme you are required by law to have backflow prevention, these are at your cost.

This ensures we protect our drinking water.

It is really important that we are all aware of the risk from backflow. For further information please phone 03 687 7200.