Rainwater Collection and Usage Essay Example | Topics and Well Written Essays - 3000 words

Rainwater Collection and Usage - Essay Example Moreover, the running costs are quite minimal. 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. Storm Water Harvesting 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 no t only harvests run off rain water from drains, roads, parks or playing fields but may also collect snow that melts into storm water systems. The surface run off may be channeled into surface waterways or into water filtration systems tasked with filtering and treating the rainwater before it is stored ready for use. Moreover, surface run off may be filtered by using rain gardens. These are planted depressions that allow water infiltration by accumulating rainwater on the surface, filtering off any pollutants before the water is absorbed into the ground. Once absorbed, the water is channeled into storage tanks via pipes. Swales may, however, be used in place of rain gardens (Gould and Nissen 2000, p. 97). These are low tracts of land, usually marshy, that filter off pollutants from surface run off and improve infiltration. This system of collecting rain water is essential in the collection of water used for irrigation, flushing toilets and even drinking once the water is treated. It is also useful as it collects excessive runoff during heavy storms, which would otherwise lead to expulsion of raw sewage from outfalls when treatment plant capacities cannot handle the combined flow. The main challenge in this system is the removal of pollutants by use of retention ponds this problem is adequately solved. Steeper slopes may