The Greater Chennai Corporation is planning to build permeable pavements across the city to reduce run-off and mitigate the effects of waterways built with cement concrete, said Corporation Commissioner Gagandeep Singh Bedi.
Speaking at a panel discussion on “Building A Resilient Chennai, Water and Climate Challenges” organised by the Chennai International Centre, Mr. Bedi said the presence of waterways built with cement concrete was one of the major causes for flooding in the city during recent rain.
He said the Corporation had decided not to use cement concrete for roads or pavements henceforth in the city. Various other proposals had been made to adopt technology to mitigate flooding, promote retention and holding ponds, he said.
“Playgrounds, parks and low-lying areas should be used as holding ponds without flooding the neighbourhood. Canals and waterways need to be widened and deepened,” said Mr. Bedi.
Pointing to the flooding of residential areas caused by cement concrete waterways during monsoon, Mr. Bedi said water from Anai Eri was flooding residential areas developed along private waterways in the southern parts of the city.
“Chettinad Enclave was flooded for 10 to 15 days. Somebody had posted it on social media. I responded and went there. We found that the apartment was standing on what once used to be farmers’ patta land where private channels used to take the run-off water from Anai Eri to Narayanapuram Eri. Urban planning does take care of the government waterways but does not take care of the private waterways. That should be considered. There are issues in urban and land use planning,” said Mr. Bedi.
Stressing on the need for diligent implementation of stormwater drain projects in Kosasthalaiyar and Kovalam basins with the guidance of civil society, Mr. Bedi said: “We want residents to watch GCC projects. We are implementing the Kosasthalaiyar project in north Chennai at a cost of ₹3,220 crore and Kovalam at a cost of ₹1,714 crore. We are putting permanent pumping stations across the city. We have reduced the distance between manholes to 2.6 metres. We have adopted engineering solutions in Bazulla Road. We need some good engineering solutions from all of you also,” said Mr. Bedi.
Spaces around lakes
Sundaram Climate Institute founder Mridula Ramesh said the government should create performance spaces around lakes. “A simple lake can provide 100 jobs. An eight-hectare lake in Madurai Mariamman Theppakulam created a source of livelihood for 126 people in March ahead of the pandemic. The 26-hectare Kodaikanal lake has created 1,500 jobs. We should explore options to make non-functional watebodies functional. We get most of our rain in 100 hours. India has the most temporally skewed rainfall. Our demand is year round. How to match the demand? The answer is storage,” said Ms. Ramesh.
“We are good at saving lives, but not quite good at saving livelihoods. Climate change has made the dry season drier and wet season wetter,” said Ms. Ramesh.
‘Monitor water use’
Environmental Foundation of India founder Arun Krishnamurthy said there was no monitoring system in each residential area about the quantum of water received and drained.
“Over 300 watebodies got revived. Why did we get flooding? Everything does not need to be concrete beautified. There is nil or absolutely minimal water sensitisation in residential areas. I don't know where my fresh water comes from. What is the quantum and quality of water I am sending out of my home? I do not understand the topography I live in, my coastal belt, my estuary, lakes and the ponds, the system connection they have. The civic society has no monitoring system of water usage,” he added.