Custom water tanks is what we do and we have thousands different sizes available for all requirements. Different sites have different rainwater harvesting challenges.  Sloping blocks might require a series of water tanks at different heights so they will balance properly.  A low set house on a large property might require squat tanks with a large diameter and low inlet height.  Whatever the challenges Select Water Tanks will help find you the perfect solution.

It can be difficult to know just how much water storage capacity you might need for a whole-of-house rainwater harvesting system.  There are several factors to take into consideration:

• Number of occupants in the household
• Average rainfall in the area
• Size of catchment (roof area)
• Available space on site
• Budget

Let’s start with a few assumptions:

• 45,000 litres of total capacity is a good starting point for a whole-of-house rainwater harvesting system
• A catchment size of 250 square metres
• The average daily water usage per person is between 150 and 200 litres. Some geographical areas report higher usage.  At the higher end of the scale, a family of four would use approximately 24,000 litres per month.
• Monthly average rainfall figures for a certain area are widely available on the internet. For this exercise we are researching monthly rainfall in Currumbin Valley, Qld.  These figures are available at  http://weather.mla.com.au/climate-history/qld/currumbin-valley

The relationship between the catchment size and rainfall is key to determining the desired capacity of your system;

10mm of rain on 100m2 of catchment will result in 1,000 litres of harvested rainwater

Other factors including evaporation, absorption, first flush diverters, or gutters full of debris are not accounted for in this example.