Rainwater Harvesting Catchment Calculator

Capture and store rainwater run-off from your roof using Enduramaxx’s Rainwater Harvesting System

With the ever-present spectre of global warming and the increasingly precious, scarce and expensive resource of freshwater affecting the whole planet, it is now essential that we all acknowledge the situation and strive to develop a sustainable society for not only ourselves but also for future generations.

It is well known that much of the water we use does not have to be purified (potable/of drinking water quality). Conservative estimates indicate that in domestic applications, 55% of the water used could be substituted for rainwater. This figure increases to 85% of water when considering the amount of water used for commerce, industry and agriculture.

Rainwater is free, and by harvesting this resource for our use, we not only provide ourselves with independent water supply during drought conditions or times of regional water restrictions but also supplement the mains supply, thus saving money. Collecting rainwater can also assist in mitigating the flooding of low-lying areas.

Harvested rainwater is suitable for many applications across all sectors, including toilet flushing, wash down/pressure washing of yards and vehicles, irrigation, dust suppression, agricultural spraying and the watering of livestock.

HOW DOES RAINWATER HARVESTING WORK?

A storage tank is fitted to your stormwater drain from your roof, and falling rain enters the tank through a filter which removes leaves and other debris.  Water pumps can pump water troughs and water cisterns,

HOW CLEAN IS THE WATER?

To remove particles and other matter, Rainwater is filtered when entering your storage tank. It is kept in the dark and oxygenated to discourage algal growth. Inbuilt calming inlets ensure that any sediment at the bottom of the tank does not get stirred up. Note: This water is not fit for human consumption.

HOW MUCH RAINWATER CAN I HARVEST?

It is particularly important to ensure that your system fully meets your requirements and options. In general, you should collect as much rainwater as possible. Use the following formula and Rainwater Harvesting Catchment Calculator for an initial calculation:

Roof area (footprint) in square metres x annual rainfall in cubic metres.

(650ml = 0.65m3), divided by 12 = average monthly rainfall capture.

e.g. 450m2 x 750ml = 337.5 (m3), divided by 12 = 28.125m3 or 28,125 litres per month average.

We recommend storing an average of two to three months’ worth of rainfall (bear in mind you may get three months’) worth in your wettest month.

Rainfall Calculator

Need help selecting which tank is right for you? Use our calculator below to make your selection easier!

Amount of Rain Harvested (litres):

Minimum Tank Size:

Assume the tank can fill 3 times per year (Depends on rainfall and usage patterns)

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