CHENNAI: The Greater Chennai Corporation (GCC) has released a disaster management perspective plan that lists out measures to prepare, mitigate and respond to disasters including floods, cyclones, earthquakes and tsunamis. The plan has taken into account the city’s vulnerabilities to disasters based on its geography, demography and social and environmental aspects.
It has also been prepared based on the principles of the National Disaster Management Plan (NDMP) and State Disaster Management Plan (SDMP). The plan takes into consideration the land use pattern in Chennai, which shows that 56.7% of the area is taken up by buildings, 17.1% by trees and 8.9% by tanks.
For cyclones, the civic body proposes a set of strategies that include retrofitting the roofs of existing critical facilities to a higher standard to ensure wind resistance and to avoid critical facilities in areas of accelerated winds in the future.
Stating that the city is flood-prone, it stresses that measures have to be taken periodically and the development of prevention methods is essential to minimise damages. Clogging of the drains due to indiscriminate dumping of solid waste and construction debris, inadequate design capacity of stormwater drains on highways and other roads, lack of connectivity of stormwater drains with macro drainage and absence of stormwater drain network in added areas were listed as reasons for flooding.
It also identifies the influence of high and low tide, the flow of excess surplus water than the designed carrying capacity into minor water bodies through tanks upstream, construction of less number of cross culverts/vents in inadequate sizes as factors that contribute to flooding. Apart from identifying the reasons, the report suggests taking up flood mitigation measures in the urban areas of Kancheepuram and Tiruvallur to reduce the flood risk in Chennai.
The GCC has mapped areas on their degree of vulnerability to floods from 2015. While there were 18 ‘high vulnerability’ locations in 2021, it had reduced to one in 2022 due to various interventions. “To address the recurrent urban floods in Chennai and its peri-urban areas, the Government of Tamil Nadu will be undertaking a study and implement a “Real Time Flood Forecasting and Spatial Decision Support System for Greater Chennai Corporation and the river basin areas of Adyar, Cooum, Kosasthalaiyar,” the report said. Apart from documenting the damages and relief work during previous disasters, the plan also outlined the responsibilities of various departments in case of emergencies.