Rain Water Tanks

All premises should be fitted with a rain water system

Rain Water Tanks

A rainwater tank can help you save up to 20% of your average household water use every year when plumbed into your home. Rainwater tank yield is dependent on climatic conditions, water collection area (ie roof size), household water usage patterns and the size of the tank. Rainwater tanks are most cost effective in the higher rainfall areas of the state.

A water catchment system can be installed in homes or premises across Perth. When it rains the roof of the premises becomes the water catchment area. The gutters on the roof funnel the rainwater into the pipes, which connect the gutters to the water tanks. Water tanks can either be placed on the ground, below ground or even be elevated above the ground on a stand or platform. The above ground round polyethylene tanks are often the most cost-effective option. Collected water can be used for a number of purposes like washing, toilet cisterns, cooking and gardening.

Tank size and rainfall

The obvious decision you need to consider when purchasing a tank is around the tank size. A good rule of thumb is to purchase a tank that holds a minimum of four weeks supply. For instance, if you use 1,000L of tank water each week in the garden, toilet and laundry combined, you should consider purchasing a 4,000L tank.

Questions you may need to ask yourself regarding a rainwater tank:

  • How often will I be using the rainwater held in my tank?
  • How much rain does the area I live in typically receive?
  • How much space do I have around my home for a tank?
  • Will my tank require any structural support?

If your tank is going to be large, consult a builder or engineer as it may require structural support. You may also need a building permit from your local council.

How much rainfall will I collect?

Each square metre of roof area collects 1 litre of water for every 1 millimetre of rainfall received. This is determined by the area of roof connected to the tank via the stormwater down pipe.

As an example:

  • An average house has a roof area of approximately 160 square metres.
  • Assume that 50% of this roof area can be easily connected to a rainwater tank i.e. 80 square metres.
  • Each square metre of roof area collects 1L of water for every 1mm of rainfall received.
  • If you have 10mm of rain, the water collected by the tank is 800L (80 square metres x 10mm = 800L).

What are the benefits of rainwater tanks?

Collecting rainwater has many environmental benefits, as well as benefiting you! Some reasons for harvesting rainwater include:

  • Making fresh water available to flush toilets or to provide a laundry source.
  • Using rainwater for drinking purposes.
  • Supplementing the watering of garden areas.
  • Reducing our use of mains water – a very valuable, limited resource.
  • Saving some money – buying less water from a service provider.
  • Providing a water source which has reduced levels of salts and other substances.

Zambezi Plumbing and Gas was Awarded “The Environment Plumbing Business in WA for 2009″. Recognition for the importance we place on the catching and storing water in rainwater tanks. We offer advice on ways to save water and to use it efficiently and offer advice on selection, installation and maintenance of all rainwater tanks.

There is a wide range of different rainwater tanks, from slim line rainwater tanks that fit down the side of a building to underground tanks. The capacity that each rainwater tanks hold varies with the size and shape. We are happy to visit and advise you on the rainwater tank that best suits your property.


Get A Free Quote

We are more than happy to give advice on which solution is most suitable for your needs, depending on your Plumbing requirements. Why not ask us to view your property and discuss the various options with you now!

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