Areas best suited for this rainwater collection system are areas with no access to water resources, and areas that receive at least 200mm of rainfall per annum as this system’s effectiveness is pegged on the intensity of rainfall received. Rainwater harvesting systems channel rainwater from the roofs into storage tanks, either placed on the land or underground, through a variety of pipes and gutters. These pipes and gutters should be strong enough to accommodate large amounts of rainwater experienced during the rainy seasons and withstand the windy conditions peculiar to heavy storms (Gould and Nissen 2000, p. 35). The storage tanks, on the other hand, must always be covered to avoid mosquito infestation and contamination from dust, bird droppings and other contaminants. A property owner may choose to use a backup valve like an aqua saver, which automatically switches from rainwater tanks to mains supply whenever available, hence saving the property owner from the hustle of having to manually switch these valves. Rainwater collected through this system can be used in irrigation and washing clothes.
However, we note that rainwater harvested from roofs may require treatment as it may be polluted by dust and dirt build on the roof. Moreover, areas accustomed to coal burning and large bird populations may produce roof rainwater contaminated by pollutants such as mercury. Residents in these areas may choose to use the water to flush toilets. It is advisable to allow the first flush of rainwater runoff as it clears the roof of any contaminants present. However, once treated, the water may become suitable for human and livestock drinking.
Another system used in the collection of rainwater waste is storm water harvesting. This refers to the collection, treatment and storage of rainwater that has run off on the earth surface, or on surfaces specifically designed for this purpose. This system not only harvests run off rain water from drains, roads,