Rainfall map for rainwater harvesting in South Africa
The rainfall map indicates the average rainfall in South Africa. In order to design a rainwater harvesting system it is critical that you look at the average rainfall in the area that you want to install the system. The rainfall will determine the design and size of the system. Major benefits can be derived from rainwater harvesting in the areas with the high rainfall. As part of our concept evaluation our team looks at the climatic data relevant to each area. This is a key design parameter that will determine the size and complexity of recovery and storage system.
Coastal cities with high rainfall (dark blue area) can gain the most with installing rainwater harvesting systems - See this article
Use rainwater to flush toilets
We frequently get request from households or companies to convert the flushing of toilets from municipal water to rainwater. Within the existing infrastructure of any building it is not that easy and the following need to be considered when wanting to do it.
1. A dedicated water supply need to be installed for the toilets, so that rainwater can be piped from a rainwater pump. This can be complicated because generally within existing plumbing systems, water supplied to a bathroom has a single supply that will go to the basin, shower bath and toilet. If the rainwater is not potable quality, a dedicated supply to the toilets need to be installed which in many instances can be quite costly.
2. There need to be a backup system for scenarios of low rainfall. If there is no water in the rainwater tank, the toilets must still be able to flush, which requires a municipal connection. This in turn can be problematic because just a simple switch-over valve can result in potential contamination of municipal water with non-potable rainwater. There should always be a physical air gap between these two water sources. It requires the design of a separation system or the installation of a back-flow prevention valve.
It is therefore much easier to design a system on the outset of planning the plumbing of a new house. The other alternative is to purify all rainwater to the house to potable standard which will not require any major plumbing alterations. Our DELUXE system is ideal for this
Greywater treatment and recovery
The term greywater refers to wash water (i.e non toilet water) coming from washing applications (showers, washbasins, car-washing areas etc.)
As water becomes more costly recycling of greywater for flushing of toilets, use in irrigation and other washing applications become more feasible. Specially in industries and businesses that use water as a cleaning medium. Car wash operations are a very good example.
By installing a greywater treatment system, the used wash water is collected, treated cleaned, sanitized and recycled back into the wash water supply. In some instances recovery rates can be as high as 90% which can result in significant savings to the business.
A combination of rainwater harvesting and greywater treatment can save a lot of money!
If you are interested in a greywater treatment plant contact us. We will do a quick cost benefit model and advise you on a greywater treatment system.
Is rainwater safe to drink?
If a rainwater system is designed and installed correctly and if the water is treated correctly it is extremely safe to drink. By implementing our design philosophy and using the correct equipment a rainwater harvesting system can deliver potable quality water that exceeds the quality of municipal water.
Water demand in Africa
Rainwater harvesting offers an affordable, simple, sustainable, and reliable alternative water source. Not only does rainwater harvesting supply water for indoor and outdoor use, it protects the environment from detrimental non-point source pollution by reducing rooftop runoff.
The water supply in South Africa today is very different than it was 100, 50, or even 25 years ago.
