To achieve its goal of ensuring water security in the city, the
Chennai Metropolitan Development Authority (CMDA) is planning to conduct
a detailed audit of the rainwater harvesting system across Chennai.
This comes in the wake of Metro Water preparing a contingency plan to
ensure uninterrupted water supply to the city as water levels in
reservoirs are slowly dipping.

The development regulations of the
CMDA states that rainwater harvesting is mandatory on all premises. The
rainwater harvesting structures installed during the AIADMK regime in
2003 helped increase the ground water level in the city, as per a Metro
Water monitoring report in 2011.

The report said that the ground water level and quality were enhanced in the sandy, clayey and rocky areas of the city.

Sources
said that the proposal was to carry out the audit with the help of
non-governmental organisations. This is expected to strengthen and
streamline the system.

Rainwater harvesting is the process of
augmenting the natural filtration of rainwater into the underground
formation by artificial methods. There are various ways of rainwater
harvesting, including collecting it from from the roof of a house or
building. It can either be stored in a tank or diverted to an artificial
recharge system.

This method is not expensive and is very
effective. Currently, rainwater harvesting is a prerequisite for
obtaining plan approvals when new buildings are constructed. Even older
existing structures have been mandated to implement it.