The lack of coordination between the Central and the State governments on completing an aerial survey for the development of a flood warning system has led to delay in generating the required data. This has left residents of flood-prone areas in the city and suburban areas wondering about their safety this monsoon season.
Residents have been waiting for a flood warning system covering the Cooum, Adyar, Buckingham Canal, Kosasthalaiar, Araniar, Nandhiar and Nagariar. Even after several meetings of officials concerned, the delay in taking up the survey has persisted, affecting flood preparedness during the monsoon. Owing to the presence of strategic installations in the city, getting clearance for an aerial survey remains a challenge.
After the floods in 2015, the civic body proposed an early warning system for rivers such as Adyar and Cooum. Smart City Mission projects also proposed various initiatives to commission infrastructure to warn residents about floods. However, the survey for an integrated flood warning project is yet to be taken up using technology such as Lidar, drones or using data from satellite imagery.
According to officials, a few neighbourhoods of Chennai and its suburbs have already benefited from the cut and cover drains developed along highways in the past few years. For example, flooding in Mudichur Road, Narayanapuram and Adhanur has reduced this year because of the development of underground drains developed using 'cut and cover' technique. "More such macro drains are required for reducing flooding in the city and suburban areas. A lot of canals have been lost because of urbanisation," said an official. The underground drains will mitigate flooding during 30 cm of rain. Rainfall of more than 30 cm needs other projects such as flood warning system.
More drains
Officials said the development of more underground drains, widening of rivers, construction of evacuation shelters and integrating them with the flood warning system are crucial aspects of flood preparedness in the city. "We will not acquire land for widening rivers in urbanised areas of Chennai. We will only remove encroachments along the rivers. The World Bank will not fund projects that require land acquisition," said an official.
The ₹3,000-crore project on flood mitigation in the State, approved by the Union Ministry of Economic Affairs, is expected to facilitate the development of more underground drains and new canals to mitigate flooding.
