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.