How big a tank do I need?

There are a few points to consider when choosing your rainwater tank. While you can never have a rainwater tank that is too big, you can certainly have one that is too small, in which case you will find yourself running out of water more often than not.

• · Step (a) Calculate your yearly water usage from the Home Water Consumption Table.
• · Step (b) Using the Rain Catchment Table, estimate the amount of rainfall you will collect as run-off from your house/shed.
• · Step (c) Depending on how you intend using the water or whether your house relies solely on rainwater, make sure you can harvest most of the rainfall falling on the roof in the wet season.
• · Step (d) Finally, look at the area available for tank/s and make sure you have enough room.
  
  
  1mm of rain over 1 sq metre = 1 litre of rainwater (see chart).