Internal connections


A licensed plumber must connect your new or existing rainwater tank into the home toilet or cold water washing machine tap. If connection to both uses is possible, it is highly recommended. The cost for an internal connection will depend on the work required. 

All plumbing work has to be carried out by a Queensland Building and Construction Commission licensed plumber. The relevant plumbing and drainage approval forms must be signed by the plumber.

Tanks connected internally are required to:

  • display rainwater stickers
  • clearly mark the water supply system from a rainwater tank at intervals of 500 millimetre with approved identification labels stating ‘rainwater'
  • install an approved sign above the tap on all external rainwater taps
  • attach approved labels to all internal taps and rainwater points


Issues to be considered when installing a town water back-up supply option:

  • all connections from the rainwater tank to outlets are required to be installed by a licensed plumber
  • as the tank is required to be connected to the toilet or cold water outlet in the laundry, you need to be able to switch over to town water if the tank runs dry
  • Council requires that there are no cross connections between water pipes from the tank and the town water pipe into your home unless there is a backflow prevention device. This is vital to prevent contamination of the town water supply

There are several options for town water back-up for internal fixtures:

  1. A trickle feed top-up system adds a small amount of town water to your tank if the rainwater level falls too low.
  2. Automatic or manual switching devices that will divert the internal connection between the rainwater tank and the town water supply when the water level in the tank falls below an acceptable level. The switch is located at the junction of the town water supply and rainwater tank supply line and is located away from the tank.
  3. A dedicated connection from the tank to the internal fixtures, with no top-up into the rainwater tank. When tank water is no longer available, you will need to swap the supply over to an existing town water supply line inside the house.


Last updated:3 May 2019