Rainwater harvesting is preferred to storm water harvesting because rainwater has less impurities and is not as polluted as storm water. In some areas, rainwater is the only available source of water, and the usual way of collecting this water is from the roof of buildings. Because the state of rainwater obtained from the roof of buildings is not safe enough for human consumption as it is, there is critical need for the water to be processed and refined to the point where it becomes adequate for domestic usage and consumed as drinking water.
Purifying rain water is essential, because, though it doesn’t contain as much pollutants as storm water, it still is not safe for drinking as it is. Why? That is like asking what is a franking machine? what is a franking machine?, The roofs of buildings are made from materials that are not really safe for the human body when ingested, but is okay for other domestic uses like flushing toilet and watering the garden.
There are various systems available for harvesting rainwater, but for individual household units, a simple set-up can be sufficient to provide the volume of water that sufficient to meet their general water needs. Another system may be required if the intention is to provide water for a larger unit such as a small community or a large community, this may require the use of a larger tank and more collection units.
A basic system may involve water being channelled from the roof of the building through pipes and gutters to a tank or other storage container. Harvesting rainwater demands that proper maintenance be done regularly, to ensure little or no contamination for the rainwater in storage.
Other maintenance procedures required for gathering rainwater include; making sure that the storage container or tank is covered always to prevent breeding of mosquitoes and reduce evaporation. If rain hasn’t fallen in a long while, it is advised that the first flow of rain should not be collected, but allowed to flow freely, so that it can clean the roof a little and get rid of dust and other contaminants that might have accumulated there.
