What are rain and storm water tanks?

Rain and storm water tanks are used to collect rainwater. In residential use, they collect rainwater runoff from pipes connected to rooftops. The information below provides some guidance on options to consider before installing one at your property. This article isn’t intended as advice and please remember it’s important to conduct your own due diligence and discuss your needs with a certified rain and storm water tank provider. 


How do they work?

Rainwater tanks can be above ground or underground. 

Rainwater is collected in a catchment area, normally a roof on a house or shed. The water is collected in the gutter connected to the roof, then funnelled into the water tank from a pipe connected to the gutters.


The water is then transported to the house via a rainwater pressure pump and pressure accumulator tank. Water flow is controlled with a pump controller. In some cases, the controller can manage the switching of water supply between the mains and tank water.

The Australian Government’s Your Home Rainwater guide is a useful resource for further information on rainwater use.


Is rainwater safe to use?

Filtered and treated rainwater can be safe to use for cooking, washing, and gardening. Ask your provider before installing as they will guide you on the right treatment system for the tank you want to install, as well as the optimum materials to use.


Gutter and tank screen guards

Gutter guards are the first line of defence for rainwater collected from roofs. The mesh filter prevents leaves, bugs and other harmful debris entering the gutter.

Tank screens act as the final line of defence. They are inserted at the top of the tank, where the water runs down the pipe from the gutter. The screen is specifically designed to keep out mosquitoes and any remaining debris which can harm water quality.


Water treatment system

Your tank will also have its own water treatment system. Common types include filtration which filters particles from water, and they may rely on electricity to operate.

UV disinfection is where ultraviolet light irradiation is used to treat most viruses and bacteria.

Chlorine disinfection is where chlorine kills bacteria and viruses.


Other water safety considerations

Certified rain and storm water tank providers also need to provide guidance on the following factors that could harm water quality and result in water contamination during the rainwater collection process:

  • Surroundings: if your property is surrounded by trees and other vegetation you will need to evaluate if the debris could cause contamination. Also determine if animals such as possums or birds and rodents are around your property as their droppings can impact water quality.
  • Roof materials: you will need a professional to examine the paints or metals used. Lead from paint or metal particles from gutters or pipes could affect your water quality.


What type of water tanks are there?

Rainwater tanks can be above ground or underground. They come in a variety of sizes - the size you choose is dependent on the space you have on your property.

Water tanks can be made from:

  • concrete
  • plastic - made from polyethylene
  • fibreglass
  • steel


What tank do I need to install?

A good place to start is by looking at where you’ll install the water tank on your property. Will it be above or underground? How much room will you have?

Discuss with your certified rain and storm water tank provider what you’ll be using the water tank for. Whether it be for your gardening, washing, and cooking needs or as a contingency water supply if you live close to a bush fire zone, your needs will determine the size and type of material you choose.


Can I still get water from the main water supply?

Yes, and you will still need to have a main connection as tank water is not suitable for personal consumption e.g., drinking. 


What do I need to do to maintain a rain and storm water tank?

Rain and storm water tanks require personal inspections to ensure optimum water quality. You will regularly need to:

  • Inspect and maintain the tank surroundings, to ensure trees, vegetation or debris that can cause contamination are removed.
  • Examine the condition of the water tank, to see if any components need to be replaced or professionally cleaned.
  • Conduct water quality tests.

Depending on the type of tank you install and the filter system you use, your provider will give guidance on what maintenance you need to do.


Are there any ongoing costs?

Over time you may need to pay for replacing components of the tank system, whether it be replacing the gutter guards, tank mesh filters, pipes or filtration system.

Check your home insurance policy to see if it covers damage to your water tank.

If you conduct periodic water quality tests, that will also come at a cost.


Do I need to comply with any water safety standards?

Below are links to some useful information specific to each Australian state and territory regarding water quality guidelines and tank use. If you are unsure of anything, reach out to your state’s health department.


NSW Health


Victoria State Government – Department of Health


Queensland Government


Tasmanian Government – Department of Health


Government of South Australia

Government of South Australia – SA Health


Government of Western Australia – Department of Health


Northern Territory Government


You may be eligible for a Green Home Loan

Looking to install a rain and storm water tank? Alongside the usual credit criteria, if your property has at least three of the following environmental features you may be eligible for the discounted Gateway Green Home Loan

  • Solar photovoltaic (PV) systems / solar panels
  • Solar battery storage system
  • Rain / storm water tank
  • Certified double glazed windows
  • Solar hot water system
  • 5 star gas or electric heating
  • External awnings
  • Solar pool heating system
  • Home insulation that meets government standards for geographic area
  • Energy efficient LED lights in over 75% of the property
  • Split systems, evaporative cooler or star rated zoned air conditioning units with either a minimum energy rating 4/6 stars or minimum 6/10 stars
  • Gas hot water system

The Gateway Green Home Loan rewards members who want to adopt a more sustainable lifestyle with a discounted interest rate.

Apply online today or speak to our member services team to find out more – because banking shouldn’t cost the earth.