Rebates for rainwater tanks

Published Date
News Topic
Sustainability & Environment

If you've found a few days of warm weather dries out your garden and increases your water use, a rainwater tank may be worth considering for your home or business.

Randwick Council is offering a rebate of up to $2,000 for rainwater tank installations as part of Community Sustainable, a program that supports houses, units and businesses in the Randwick local government area to implement energy and water saving initiatives.

If you already understand how rainwater tanks work, you can click here to skip to the rainwater tank rebate section below. If not, we have put together some responses to frequently asked questions about rainwater tanks.

What are the benefits of rainwater tanks?

Rainwater tanks capture water from your roof for use in garden areas or to reduce your mains water consumption. As well as this, rainwater tanks also decrease the excess stormwater which runs off roofs and contributes to flash flooding and the pollution of oceans and waterways.

By installing a rainwater tank in your home or business, you divert this water for a useful purpose. It is best to consider how you would make use of a rainwater tank before you decide to install one. Whilst rainwater tanks are effective for garden areas and irrigation, the most savings come from plumbing a rainwater tank into your laundry or toilets as these offset your mains water use. Sydney Water estimates that a correctly plumbed in rainwater tank could save up to 40% of your drinking water supply and $200 per year on water bills3. However, internal connections also increase the installation cost and must be completed by a licenced plumber.

What are the main components of a rainwater tank system?

There are a few key components required to ensure that the water which enters and leaves your rainwater tank is clean and suitable for use. The process starts on your roof and gutters which is where the rainwater is collected. Gutters are typically fitted with gutter guards which reduce the amount of leaves and debris which enter your downpipes. An effective gutter guard is the first filter of your rainwater tank system and is essential for keeping the other components in the system from getting clogged up.

Water then flows down your downpipes and through your first flush diverter which diverts the first part of the rainwater from your roof into a separate chamber and away from your rainwater tank. These are another critical component of a rainwater tank system as the first part of the rainwater from your roof is often dirty and contaminated, especially if it has been a long time since the last rain.

Once the dirtiest water has been removed via the first flush diverter, the cleaner rainwater then commonly passes through some final filters, such as a leaf eater (which is a meshed filter) and a inlet screen (which sits at the top of your tank under the inlet pipe). Inlet screens are required for all rainwater tank installations in NSW to reduce mosquitos breeding and vermin entering your tank.

Clean water then leaves your rainwater tank via the tank outlet which is located at the base of the tank. A tank overflow is also included at the top of your tank to allow any excess rainwater to flow from your tank into your stormwater drain or a second rainwater tank.

If you would like to plumb your rainwater tank into your laundry or toilet, or if you would like to pressurise your rainwater, then you will also need a pump. Pumps are either located outside the tank (external pumps) or inside the tank (submersible pumps). Whilst external pumps are known for being more durable, submersible pumps are known for being quieter to run.

Finally, if your rainwater tank is plumbed into your home, then you will also a require a rainwater-to-mains switch which will change the water source from your tank to the mains water when your tank is empty.

What size rainwater tank should be installed?

There are a lot of factors which should be considered when choosing a tank, such as the size of the roof and what the rainwater will be used for (e.g. irrigation or toilets). However, ultimately the tank size is limited by the amount of space you have available. It is best to speak to a rainwater tank installer to determine a suitable tank for the space available.

Sydney Water suggests that if price is a limiting factor then you should consider a minimum tank size of 2,000 litres, connected to 75% or more of your roof area3. To be eligible for Council's rainwater tank rebate, the tank size must be at least 1,000 litres.

Remember, a 1,000 litre tank will weigh 1 tonne! So, it is generally best to locate your rainwater tank on a concrete base.

Do rainwater tanks require maintenance?

Rainwater tanks are known to be 'low maintenance', not 'no-maintenance'. Most maintenance (such as cleaning out filters) is recommended every 3-6 months. However, this may increase or decrease based on the amount of tree canopy you have above your roof. Council recommends you visit the Sydney Water rainwater tank page and watch the 'how to maintain your tank' videos before purchasing your rainwater tank.

Rainwater Tank Rebate


Randwick Council is providing a rebate of up to $1,000 for installing rainwater tanks in houses, and up to $2,000 for installing rainwater tanks in units1 and businesses, in the Randwick Local Government Area.

Eligibility Criteria: Rainwater Tank Rebate Fact Sheet

Visit Community Sustainable to apply!

1 Units refers to all types of multi-unit dwellings such as apartments and townhouses.

2 The WaterFix® rebate is $100 or equal to the cost of the WaterFix® purchase if this is less than $100. 


Visit Community Sustainable for a full copy of terms and conditions.

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