Using your rainwater tank | Brisbane City Council

Using your rainwater tank

Rainwater tanks reduce stormwater from properties, improving local creek water quality and habitat for local flora and fauna. They can also reduce the need for new or replacement water supply and stormwater infrastructure. 

Brisbane City Council does not recommend using rainwater for drinking, cooking and other potable purposes, as the quality of stored tank water can vary greatly.

Maintenance

Under the Queensland Plumbing and Drainage Act 2002, the property owner must maintain plumbing and drainage on their property. This includes all apparatus, fittings or pipes for supplying water to the premises from a service provider’s infrastructure or from a water storage tank and for moving water within a premise.

You need to regularly maintain your rainwater tank system to:

  • ensure clean water
  • protect the health of your family, the local community and the environment

Simple ways to keep contaminants out of your tank system are to:

  • keep your roof clear of large tree branches
  • keep gutters and downpipes clear of leaves and debris
  • check inlet and overflow screens are securely in place, are in good condition and cleaned regularly
  • install a first flush diverter which stops the initial flow of water from your roof from entering the tank
  • open and cleaning out first flush devices after rain
  • check the tank and fittings regularly for leaks
  • replace cartridges in water filters and chemicals or components in water treatment units strictly according to manufacturer’s instructions
  • check sludge levels in the bottom of the tank every two to three years or if you notice any sediment in the water
  • remove sludge before the layer builds to the level of the tank outlet – usually once every five to ten years
  • avoid using harsh cleaning products that may contaminate your rainwater

Do not enter the tank as this is dangerous and should be left to professionals.

Corrosion

Direct contact between different metals or run-off from one metal surface to another can cause accelerated corrosion or holes when metals are wet. Metal roofing materials, roof accessories, gutters, screens, piping and steel rainwater tanks can cause or be affected by corrosion.

Mosquitoes

Mosquitoes breed if they get inside a tank or systems where water does not drain from pipes, gutters and plumbing. Mosquitoes can carry diseases like Ross River and Dengue Fever.

You can stop mosquitoes breeding in your rainwater tank by:

  • ensuring there is no debris in the tank
  • installing guttering that stops water pooling
  • ensuring water does not pool on the tank lid
  • sealing all entry routes to the tank including inlet and overflow pipes with mosquito-proof screens

Mosquito-proof screens should:

  • have openings less than one millimetre squared
  • be made of stainless steel or aluminium
  • be secure but removable for cleaning. In some systems, screens can be incorporated into a rainhead, first flush device or underground filter pit

If you find mosquito larvae or wrigglers inside the tank, you can destroy them by adding a small amount of liquid paraffin or edible kitchen oil to form a thin film on the surface of the water. This stops any hatched mosquitoes flying off. Find out how the mosquitos got into the tank and seal off the entry route.

Read about water storage and mosquitoes.

28 June 2018