Though water harvesting techniques had been evolved and developed in India centuries ago, it is frequently being used today, specially in the major metro cities as they face severe water scarcity. Rainwater harvesting helps make the maximum use of a free resource such as rain water.
A building’s rooftop is used as a catchment area in most harvesting systems. The rain water is channeled from gutters into pipes that lead to a storage tank from where it can be used for household use or for recharging groundwater.
Mandatory in 18 states
In India 18 states have made rooftop rainwater harvesting systems mandatory for new buildings. The Karnataka state government proposes to give five to 10% rebate on the water bill for those practicing rain water harvesting. Over a period of time it is expected that this would help solve 40- 45% of the urban water problems.
Fresh directives have been issued by the Delhi government to all its departments, local bodies and public sector undertakings to install rain water harvesting systems in their buildings. The building norms in the capital are also being modified to make it mandatory for all the departments to provide plans for installing rain water harvesting system in all new buildings with area space of 100 square metres and above.
Mumbai, Chennai, Indore
Mumbai, faced with acute water shortage, had made it mandatory for all buildings with a plot area of 1,000 square metres or more to adopt rainwater harvesting. In 2007, it was made compulsory for buildings with plot areas of 300 square metres. But due to the lack of proper monitoring systems, only 900 buildings had actually implemented the plan till June 2009.
In Chennai rainwater harvesting has been made mandatory in three storied buildings (irrespective of the size of the rooftop area). All new water and sewer connections are provided only after the installation of rainwater harvesting systems.
In Indore in Madhya Pradesh rainwater harvesting has been made mandatory in all new buildings with an area of 250 sq m or more. As an incentive for implementing the scheme, a rebate of 6 per cent on property tax has been offered.
See a small documentary on how we can save and preserve precious rain water by harvesting water from rooftop.
