Rain Water Harvesting

The system employed in catching, storing and using the water for domestic purposes is called Rain Water harvesting. Water can be harvested from Rain directly on roof tops and other structures or can be harvested in the basement of high rise ground structure like hills and hillocks. The former is called Rain Water Harvesting and the latter is called Storm Water Harvesting.

Rain Water Harvesting

This technique is more common and many cities around the world have adopted this methodology to conserve water. The most common way of harvesting water is the collection of rainwater on roof tops. This roof top water is then channeled through many layers for filtration and then stored in structures like tanks from where it can be accessed for intended purposes.

In the city of Chennai, Rain water Harvesting is a prerequisite for obtaining plan approvals when new buildings are constructed. Even older existing structures have been mandated to build Rain Water Harvesting structures. Hence Chennai builders are conscious of Rain water harvesting structures as this
is a mandated structure as per CMDA set of rules. This rule has been incorporated as a Government Order and a deadline was given by October 2003 that that all Chennai buildings have mandatory RWH structures. These days Chennai Builders are mandated to obtain Rain Water Harvesting systems in their projects for getting new water and sewage connections. This rule is applicable for individual buildings that may be constructed by anyone apart from Chennai builders.

The water collected through Rain Water Harvesting Structures in Chennai are not used directly for consumption but are redirected to ground in a bid to recharge the ground water level by one of the following structures viz., open wells, recharge wells, Percolation Pit, Recharge Trench, Recharge Shaft etc.. The ground aquifers are recharged by this simple method. There are examples of some Chennai builders who use innovative technique by capturing the rain water in roof top and using the same for purposes like flushing toilets, washing clothes, watering the garden etc., which in any case constitutes some 50% of the amount of water used typically in any household.

Raindrops Promoters, a Chennai Builder in its ongoing project, The Royal Chariot at Medavakkam has incorporated a roof top garden in one of its unit and the garden will get its water from the rain water harvested directly on the upper roof top.

Construction of Rain Water Harvesting System

In Chennai Flats and Chennai individual houses, rain water harvesting system typically contains the following, the roof top on which the rain water is harvested, pipe which is connected to the outlet from the roof top, a ground level Recharge pit / trench / well / shaft with or without bore is connected to the other end of the pipe that leads it way from the roof top.