Rainwater tanks

Rainwater tanks are a great way to decrease your demand on treated water from mains water, as well as reducing the stormwater run-off which can pollute waterways.

Tank water can be used for purposes such as flushing toilets, washing clothing, topping up swimming pools, watering the garden or washing your car.

Things to consider when choosing a rainwater tank

What will you use the water for?

This will affect the size of the tank you select. A minimum 5000 litre tank is recommended when using the rainwater for household activities. Internal as well as external use of rainwater is the best environmental outcome, as it ensures that the water in the tank is used regularly.

How big is your roof?

Roof area determines how much water you can collect. If rainwater is only able to be collected from part of your roof, you may need to adjust your downpipes or install more than one tank.

Do you have enough space for the tank?

A traditional round 5000 litre tank will need an area of 1.7 metres in diameter and 2.3 metres in height. Underground tanks are an option, but they can be expensive and you will need a DA. Slimline tanks may be a better option for limited space. They can be installed between the side of the house and the fenceline provided there is a 450mm gap for access.

How will you maintain the tank?

Dust and debris on the roof of the house can contaminate the water. A flush-first device should be used, and it should be regularly cleaned. Gutters and leaf-screens should also be regularly checked.

What about mosquitoes?

To prevent mosquitoes from entering the tank, all inlets and outlets to the tank will need to be blocked with insect-proof screens.

Do I need a development application to install a rainwater tank?

Willoughby City Council residents are not required to lodge a development application (DA) for a rainwater tank as long as the applicable points within the SEPP (Exempt and Complying Development Codes) 2008 are met. 

For more information on rainwater tanks, visit the Sydney Water website.