Rain harvesting systems provide eco-friendly, reliable and cost-effective solutions for homeowners and businesses wishing to make better use of freely available rainwater.
Although people have been harvesting rainwater for thousands of years, it is only recently, in the wake of a growing global water crisis, that sophisticated and well-engineered systems have been developed. They allow homeowners, businesses and industry to collect or “harvest” rainwater from roof and storm water run-off, and store it for future use for irrigation, clothes washing, toilet flushing and bathing. Properly treated, it can also serve as an emergency source of drinking water.
The severe drought experienced in many parts of the country over the last year, especially throughout the Eastern Cape, as well as the ever-increasing cost of water, has prompted many South Africans to rethink the issue of ongoing water security.
Still a relatively new concept in South Africa, rainwater harvesting is used extensively in water-stressed countries, such as Australia, or those with progressive water security legislation, such as Germany and parts of the United States. Rainwater is collected from storm water run-off, roofs or through permeable paving and then stored in a range of tank systems before being plumbed back into a building.
Rain Harvesting Systems installs a range of systems suitable for anything from private homes to large industrial sites. Says Sean Dowds, director at Rain Harvesting Systems: “The HDPE (high-density polyethylene) of which the tank is made is one of the safest food-grade plastics. It plays a dual role of protecting the steel reinforcement from corrosion and protecting the stored water against leaching of heavy metals and chemicals.” Every tank comes complete with an access manhole with lockable cover.
The beauty of the system is that it continues to yield financial savings. “A 1 600m2 roof area for example, would yield enough water from a small 20mm rainfall to fill a 30 000-litre tank. In drought-stricken areas, such a system could make the difference between having water or having to go without, not to mention the financial savings to be made if water tariffs increase, something that seems inevitable in the not-too-distant future,” says Dowds.
Rain Harvesting Systems offers three options for residential applications – they are as follows:
The Eco Rain Wet System: This system comprises an above-the-ground tank that can be hidden anywhere in your garden. Rainwater is collected from the roof and channeled into underground pipes that lead directly to the tank. The system boasts a 5 000-litre above the ground, round, roto-moulded tank, complete with mosquito and insect proofing. It can be upgraded to a larger capacity if required. The estimated annual water savings from this system amounts to approximately 130 000 litres per annum. The cost of this system starts at R16 474.
Eco Rain Starter: This system provides the simplest way of starting to harvest rainwater – there is no need for any excavation and it can be fully installed in a matter of hours. It comprises a 2 200-litre above-the-ground, round, roto-moulded tank with complete mosquito and insect proofing that is installed alongside the house. The cost of this system starts at R6 650 and the total water saving per annum amounts to approximately 60 000 litres.
The Eco Rain Underground: Similarly, this system collects rainwater from the roof and channels it through underground pipes to an underground, out-of-sight tank. This is the ideal solution for homes with small gardens or if you would just like to have the tank completely hidden from view. The system boasts a 5 000-litre mosquito and insect-proof tank, but it can be customised to store much more water if required. The cost starts at R23 025 and the system can save approximately 130 000 litres of water per annum.
There are a multitude of additions to these tanks to ensure that only the best quality water is stored. For example, the Leaf Beater Rain Head is connected to downspouts with a self-cleaning, insect-proof screen to prevent leaves and large debris from entering the tank. Before the tank is filled, First Flush Diverters flush away the first millimetres of rainwater to ensure that only clean water enters the tank. The pipes are drained of any stagnant water after each rainfall, and the Tank Vacuum removes sediment form the bottom of the tank every time it overflows. It also helps oxygenate the water by getting rid of anaerobic water from the bottom of the tank. A tank gauge can be installed to indicate how full the tank is. – Antonella Dési
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