Rainwater Tanks

Conserving water is becoming increasingly important. Rainwater tanks are an efficient means of reducing use of potable (drinking-quality) water while controlling and using rainwater.

Residential water use consumes 50% of all water supplied by Sydney Water and it has been estimated that outdoor water use can be as high as 50% of our daily domestic use. Using rainwater to irrigate gardens and lawns, to wash your car, flushing toilets and washing clothes conserves a valuable resource that would otherwise go to waste.

Council has a Rainwater Tanks Policy.

What type of tank should I install?

Tanks are available in a variety of shapes, materials and colours. You can install a traditional round tank or a slimline rectangular tank that are designed for restricted areas. Dimensions will vary with individual tank shapes.

However, rainwater storage is not limited to traditional external tanks. Designs are available incorporating storage in gutter systems, boundary fences, cisterns and built into the structural components of a building.

Rainwater tanks and storage units are available in a wide range of materials including galvanised steel, concrete, fibreglass or plastic. All of these materials can be suitable providing the unit has been manufactured for the collection of rainwater.

Do I need approval?

Council requires all new residential dwellings be fitted with a rainwater storage facility with a minimum capacity of 3,000 litres that is connected to toilets and washing machines and is available for outdoor water use.

Approval for rainwater tanks in new dwellings will be given as part of the development consent for the construction of the dwelling.

With existing dwellings, no development application or approval is required for the installation of rainwater tanks up to 10,000 litres in capacity and where it is installed in accordance with the conditions to State Environmental Planning Policy (SEPP 4) Part 4 Clause 16. Any proposed rainwater tanks outside this criteria, will be subject to the lodgement of a development application prior to installation.

Is the water safe to drink?

The use of rainwater for drinking purposes is NOT recommended. Water quality in urban rainwater tanks is affected by:

atmospheric pollution vehicle emissions
faecal material from birds, mice, rats etc
roofing materials and paints, including lead from flashings
leaves and dust
accumulated sludge in the tank.

Accordingly the provision of clear signage adjacent to the taps is recommended advising against the use of rainwater from the tank for drinking purposes.

Where should I put my rainwater tank?

The rainwater tank and its associated drainage, plumbing and supporting structure must be designed and positioned in such a manner that it maintains the visual amenity of the immediate surrounds. Installation must not adversely affect the amenity of neighbouring premises.

You should select materials, colours and shapes that are compatible and blend with and complement the existing attached building, adjoining buildings and streetscape.

What are the maintenance issues with a rainwater tank?

To ensure that the water collected from your roof is healthy, proper maintenance is required. Roof catchments should be kept clean and clear of leaves and debris. Gutters also need to be regularly inspected and cleaned if necessary.

When installed, every access point except the inlet and overflow should be sealed to prevent contamination. The inlet should incorporate a mesh cover and a strainer to keep out materials such as leaves and to prevent the access of mosquitoes and other insects. The overflow should also be covered with an insect-proof screen.

All screens should be cleaned regularly. Tanks should not be allowed to become breeding sites for mosquitoes. If mosquitoes are detected in the tank, the entry point should be located and closed. For most types of tanks mosquito breeding can be stopped by adding 2-3 tablespoons of domestic kerosene.

Tanks should be examined for accumulation of sludge at least every 2-3 years. If sludge covering the bottom of the tank is evident it should be removed by siphon or by complete emptying of the tank. Professional tank cleaners can be contracted.

For more information on installing a rainwater tank please call Council on 9840 9981 or email web2@holroyd.nsw.gov.au or contact Sydney Water on 13 20 92.