Buying & installing a rainwater tank

Thinking about buying a rainwater tank?

Selecting the right size and type of tank is just part of the purchase decision.

Follow the steps below to ensure the whole rainwater tank system meets your needs and delivers an efficient and reliable source of water.

How to choose the right tank

Rainwater tanks are large, very heavy when full and can cause harm if they aren’t installed or maintained correctly. A number of regulations are in place to help ensure your tank is safe and suitable. 

Contact your local council to see if they have any requirements you need to comply with. This may include a maximum height, placement, or distance from your property boundary.

Tanks that can store a maximum of 10,000 litres of water don't normally need council approval. However, there are a number of conditions you must comply with. 

Refer to the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 and scroll down to the Subdivision 32 and Subdivision 33 headings.

Do some research and see what's on offer before you make a decision. If you get quotes from at least three rainwater tank suppliers, you'll find the right solution for the best price. 

Key decisions Considerations
Tank size Try to work out which tank size will deliver the greatest savings for your home.

There are a number of websites and apps that can help you find the right tank size. You'll also need to consider your budget and how much space you have.

Don't forget to pour a concrete foundation!
Tank type Tanks come in a wide variety of sizes, shapes and colours.

You can also choose a below-ground tank. These are much more expensive to buy and install, and need extra further backflow prevention measures.

Where you can locate your tank will influence the type of tank you can use.
Pump type Most tanks need a pump to supply water at the same pressure as your drinking water supply. These may be external pumps that sit on the ground, or submersible pumps that sit inside the tank.

External pumps tend to be more durable and last longer. Submersible pumps are considered to be quieter and as they're inside your tank, they don't take up extra space.

Ideally, submersible pumps should have their intake raised from the bottom. This stops the pump from taking in the dirty water at the bottom of the tank.

There can be a variety of problems that affect your pump and stop it working, including water leaking into the pump and shorting the circuit, or parts deteriorating due to wear and tear.

If you have a problem with your pump, we recommend that you contact a pump repair specialist to assess and quote to fix it. If you need a new pump, buy an external pump if possible and ensure it's fit for purpose.

We recommend a small external pump for simple domestic purposes. This will depend on your rainwater use, property size and irrigation.

Smaller pumps tend to be more energy efficient. You can buy a pump cover to minimise noise and protect the pump from the elements.
Installation options Consider how the tank connects to your home's downpipes and then to the stormwater pipes.

Maximising the roof area flowing to your tank is the best way to maximise your water savings, regardless of your tank size.
Price If price is a limiting factor, consider a minimum tank size of 2,000 litres, connected to 75% or more of your roof area.

Make sure you can afford to have it connected to at least one regularly used internal plumbing fixture like a toilet or washing machine and to as much of your roof as possible. This will help you receive maximum value.
 

When it's time to choose where to place your tank, you and your installer need to balance three key goals:

  • Maximising the tank's catchment area.
  • Minimising the plumbing and connection costs.
  • Providing a safe and stable foundation as the tank will be heavy once it's full of water. Remember, 1000 litres = 1 tonne!


Check the suitability of the proposed location well before the tank arrives.

Read the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 (scroll down to Subdivisions 32 and 33) and talk to a good tank supplier for site-specific considerations.

You can't install a rainwater tank over our water or wastewater mains
Due to their weight when full, tanks can't be installed over our water or wastewater mains. 

Call us on 13 20 92 to check the location of our mains.

To do its job well and deliver clean, clear water, your new tank will need to be properly connected.

What do you need to do?

  • Check that your roof and guttering are suitable to collect rainwater. Don't collect rainwater from roofs with lead-based paint or flashing, bitumen based products or with exposed, treated wood.
  • Prevent blockages from overhead trees by installing gutter guards or downpipe screens.
  • Prevent insects (and any other animals) from entering your tank. Your rainwater tank inlet and overflow must be mosquito proof and you must ensure there's no other point of entry.
  • Use a first-flush device. This is a simple and effective way of only letting the cleanest water into your tank.
  • Install a fail-safe, top-up water connection or an auto-switching device to supply drinking water when the tank is empty.
  • Add energy efficient accessories like a pressure tank to your pump. These reduce the number of times your pump runs, saving energy and maximising the pump's life.
  • Consider how you'll use your rainwater before buying a water filter. Many filters are not suited for rainwater as they clog quickly and dramatically increase your pump's energy use.

We recommend that you hire a licensed plumber who's experienced with rainwater tank installations.  Your tank will need plumbing connections to deliver water from your:

  • downpipes to your tank
  • tank (when it's overflowing) to the stormwater system
  • tank to your pump
  • pump to your garden taps, toilets, washing machine, hot water system and/or household plumbing.


You may also need an electrician to provide a safe power supply for your pump and auto-switching device.

Your plumber will need to book and pay for a NSW Fair Trading inspection for any rainwater tank installations:

  • that are connected to a toilet, washing machine or hot water system
  • where the tank is topped up by, or switched to, the drinking water supply when it's empty.


Don't forget to ask your plumber for your Certificate of Compliance when the work is done.