Find out about the eligibility and associated conditions if you apply for a water service from a distribution or trunk main.

The primary function of distribution or trunk mains is to convey bulk water from the various sources to reservoirs where water will enter the scheme supply network, and be treated for customer consumption.

Trunk mains operate at very high pressures, which is why fittings capable of operating under high pressure are required. They are installed in a manner that does not compromise the integrity and management of the main.


Water connections from distribution or trunk mains will only be provided as an option of last resort at section valves and then only if a by-pass arrangement is constructed at a cost to the applicant.

To be eligible for a water connection to distribution or trunk mains, the property must:

  • be within our Water Services Licence Area
  • not serve a subdivision were the Western Australian Planning Commission has placed a water condition that requires a reticulated water supply
  • not be in an area already served with a scheme water supply
  • not be for fire fighting purposes.


A service will only be considered when the following conditions have been met:

  • The main is adjacent to, or within, the lot boundary where the service is required.
  • The connection point is at a section valve, with a by-pass arrangement, at a point agreed to by the corporation and no further than 1,000 metres from the house connection point.
  • The pressure at the connection point cannot exceed 200 metres head.
  • All connection costs will be met by the applicant and the arrangement must be economical and feasible for Water Corporation.
  • The applicant agrees to place a notice on the property title advising the property has a non-standard water service and that all prospective purchasers will have to enter an agreement with Water Corporation for the continuation of the water service.

Service agreement

For a service to be approved, you will need to enter into an agreement acknowledging the following:

  • The need for a tank, with a minimum storage of 9kL, to provide an alternative water source during interruptions.
  • All private plumbing connections to an on-site tank with an automatic inlet control valve must come from the outlet side of the tank.
  • The need for pumping if the pressure is low, or if the pressure is high, a pressure reduction valve. Fittings must be of a certain standard to comply with the design pressure rating of the pipeline.
  • The need to treat the water to drinking water standard at point of use if it's for domestic purposes.
  • Payment for the installation of all pipework (including valves and fittings) from the main to the connection point.
  • It is your responsibility to protect the meter and accept liability for cost of any repairs they are liable to pay:
    • all relevant infrastructure contributions, connection charges and building fees
    • service and water usage charges
    • for water lost through leaks and bursts in the private main. There will be no allowance for leaks and bursts.
    • Where a main is extended to or past the property, you will need to make application to disconnect the non-standard service and connect the new main within 3 months of the service being provided.

How to apply

Complete the service by agreement application form and submit it by one of the following options:

Post: Building Services, PO Box 100, Leederville WA 6902


Once your application has been processed, we will email you an invoice outlining the relevant fees. We require payment before a work order for the water service can be generated.

More information

For further information please call us on 13 13 95.