Article by Sam Braidley

Why does Rain Water Harvesting and it’s conservation deserve your consideration? Surely there is an abundance of water everywhere. Except in deserts and arid areas the rain continues to fall on earth as being happening for millenniums before which will flow down the rivers to sea, isn’t that so? Sad to say this is not so. Life giving and sustaining Water is a limited resource. And it keeps on dwindling at an alarming rate. Reservoirs  are drying up all over the world which is evident specially in the poverty stricken countries where pure drinking water it self is scarce. Crop failure due to rain and ground water shortage leads to mass exodus of populations leading to chaotic situations like famines, violence and break down in law and order. And it is not the increase in consumption alone which is responsible for this situation. Our own callous disregard for conserving this valuable resource and our attitude that water does not need to be conserved are two of the major causes.Rain Water harvesting as a solution? Rain is an important link in the cycle of water. Desalination and purification of water by evaporation of   sea water and vegetation and other living organisms cause cloud formation leading to all important rain. Rain Water Harvesting is the management of this rain by controlling and proper utilization at the point of reaching ground surface. Unfortunately Rain Water Harvesting is not the complete solution to your total water requirement at your place of living or work. It however makes a significant contribution towards solving your   day to day water problems, not forgetting the contribution it will make to the well being of the environment.Types of rain water harvesting Rain Water Harvesting (or RWH) can be broadly categorized as:

Domestic Rain Water HarvestingAgricultural, Irrigation, Soil Erosion Management and aquifer topping up  related Rain Water Harvesting

How is Rain Water Harvested? In domestic RWH most commonly the building roof itself functions as the harvesting surface. Depending on the level of sophistication required RWH could even be a plastic sheet with centre depressed and having a hole. The first couple of liters is not stored but will be discarded to get rid of impurities that collect. House roofs are too made use of to collect the rain water where the task is made easier if it is already fitted with gutters and down pipes. The down pipe is directed directly to the storage tank or the vessel which may be located below or above ground. In non domestic applications these vary from small tanks above or below ground (using lift pumps and overhead tanks), up to large artificial reservoirs which irrigate vast areas of cultivations and human settlements. The water management in the latter instance is done with huge dams, sluice gates and open irrigation canals.Is Rain Water harvesting a comprehensive solution for your water requirement? Emphatically no! It is only a conservation measure of precious and hard to find water. It will only supplement the normal supply of water to the premises. One reason for this is that RWH systems depend on a lot of variables such as:

Cost and economic factorsClimate and weather patternsHydrologySocio-Political FactorsTechnologyGeo-physical factors

Are there economic benefits in RWH systems? While it is not outwardly apparent, Rain Water Harvesting brings economic benefits even at domestic levels. The initial investment is hardly anything as roofs and gutters are already in place and storage tanks too are already there. On the other hand in non domestic applications settling tanks, pumps, aerators and filter beds may be a few additional requirements depending on their capacities. The cost of potable water is rising regularly. Apart from drinking water, it is mandatory for large multi storey buildings to keep in reserve large quantities of water for fire services. Many businesses require large quantities of water where an increase in tariffs will affect production costs. Some of these costs can be offset with harvested rain water.