Chennai: How to save a city from sinking | Chennai News
CHENNAI: It’s 1921. A walk on Mount Road is quite pleasant as the road passes through a body of water at Teynampet – the Long Tank which curves west and meets the Nungambakkam Reservoir. One hundred years later, there is no trace of these vast bodies of water.
Instead, a bustling T Nagar and Nungambakkam developed into commercial areas in its place, as city managers at the time did not think about the usefulness of having a tank in the middle of the city.
This story continues to unfold in many parts of the city as the population grows and the pressure for housing increases. Reservoirs, lakes and floodplains have been turned into settlements – legally and illegally. It made the city sink after heavy rain, every time, like it happened last week.
the Adyar, Kosasthalaiyar and Cooum rivers; the Buckingham Canal and two Pallikaranai and Kattupalli marshes – though shrunken, have survived. However, much of these have been occupied as authorities prioritize development over long-term planning and conservation. Thus, the city, which suffered little flooding when it rained 60 cm in two days in 1985, is no longer able to withstand 25 cm of rain in 17 hours.
This model will no longer work if city managers want to provide a better quality of life, experts say.
To cope with heavy rains or downpours, the city needs natural canals, lakes, floodplains, marshes as well as an efficient drainage network to drain flood water and store excess water. rain. Pumping stations in low areas, reclaiming natural streams, creating buffer zones in suburbs and saving what remains of floodplains are the solutions, a few suggest.
When these are in place, the city will need a robust flood warning system capable of real-time monitoring in flood-prone areas, identifying critical blockage points before it rains, to verify the efficiency of the current drainage network and its bed slope, to map the alternative ways of draining water and, finally, to keep our drainage systems clean.
“You can’t prevent flooding, but you can mitigate it. Whenever a flood occurs, we must ensure that the flow goes either to the nallas, or to the natural streams, or to the rivers and finally to the sea as soon as possible ”, said BV Mudgal , director of the Center for Water Resources, Anna University.
It is very difficult for the city to evacuate the storm water because the natural drainage channels such as the wetlands and the flood plains of the Cooum and Adyar rivers have been blocked due to urbanization ”, said MV Ramana Murthy , director of the National Center for Coastal Research (NCCR). The way forward is to have an integrated drainage network system for the city. “We should see if the drainage system is sufficient and come out with pumping stations where the drainage system does not work. We also need to identify critical blockage areas before the heavy rains, ”he added.
Professor Balaji Narasimhan of the Civil Engineering Department of IIT Madras, suggested that the conservation of the Adyar River floodplains in the upstream areas like Mution is still nascent, could save the city from flooding. “Once you get under Anakaputhur, there are no more flood plains for the Adyar River. The government is expected to buy revenue land in Mudichur and Thirumudivakkam and convert it to flood plains. It is better to hold any excess water there than to come to the downstream areas, ”he said. He is crowdsourcing flood data for the 2021 floods in the city.
“Frequently flooded pockets in Pallikaranai and Velacherry should be converted into buffer zones where water can be dispersed,” he added.
Some low-lying areas like Velachery need pumping stations, valves and embankments because the topography and soil type do not allow rapid discharge of floodwater, Narasimhan said.
Urban planning expert and former bureaucrat MG Devasahayam said, “Removing all encroachments and restoring natural drains and lakes to their original form is the solution. ”
He pointed out that even central and state governments have not spared Chennai’s waterways Examples: MRTS on the shores of Buckingham, a highway dividing the Pallikaranai Marshes and an elevated highway
Instead, a bustling T Nagar and Nungambakkam developed into commercial areas in its place, as city managers at the time did not think about the usefulness of having a tank in the middle of the city.
This story continues to unfold in many parts of the city as the population grows and the pressure for housing increases. Reservoirs, lakes and floodplains have been turned into settlements – legally and illegally. It made the city sink after heavy rain, every time, like it happened last week.
the Adyar, Kosasthalaiyar and Cooum rivers; the Buckingham Canal and two Pallikaranai and Kattupalli marshes – though shrunken, have survived. However, much of these have been occupied as authorities prioritize development over long-term planning and conservation. Thus, the city, which suffered little flooding when it rained 60 cm in two days in 1985, is no longer able to withstand 25 cm of rain in 17 hours.
This model will no longer work if city managers want to provide a better quality of life, experts say.
To cope with heavy rains or downpours, the city needs natural canals, lakes, floodplains, marshes as well as an efficient drainage network to drain flood water and store excess water. rain. Pumping stations in low areas, reclaiming natural streams, creating buffer zones in suburbs and saving what remains of floodplains are the solutions, a few suggest.
When these are in place, the city will need a robust flood warning system capable of real-time monitoring in flood-prone areas, identifying critical blockage points before it rains, to verify the efficiency of the current drainage network and its bed slope, to map the alternative ways of draining water and, finally, to keep our drainage systems clean.
“You can’t prevent flooding, but you can mitigate it. Whenever a flood occurs, we must ensure that the flow goes either to the nallas, or to the natural streams, or to the rivers and finally to the sea as soon as possible ”, said BV Mudgal , director of the Center for Water Resources, Anna University.
It is very difficult for the city to evacuate the storm water because the natural drainage channels such as the wetlands and the flood plains of the Cooum and Adyar rivers have been blocked due to urbanization ”, said MV Ramana Murthy , director of the National Center for Coastal Research (NCCR). The way forward is to have an integrated drainage network system for the city. “We should see if the drainage system is sufficient and come out with pumping stations where the drainage system does not work. We also need to identify critical blockage areas before the heavy rains, ”he added.
Professor Balaji Narasimhan of the Civil Engineering Department of IIT Madras, suggested that the conservation of the Adyar River floodplains in the upstream areas like Mution is still nascent, could save the city from flooding. “Once you get under Anakaputhur, there are no more flood plains for the Adyar River. The government is expected to buy revenue land in Mudichur and Thirumudivakkam and convert it to flood plains. It is better to hold any excess water there than to come to the downstream areas, ”he said. He is crowdsourcing flood data for the 2021 floods in the city.
“Frequently flooded pockets in Pallikaranai and Velacherry should be converted into buffer zones where water can be dispersed,” he added.
Some low-lying areas like Velachery need pumping stations, valves and embankments because the topography and soil type do not allow rapid discharge of floodwater, Narasimhan said.
Urban planning expert and former bureaucrat MG Devasahayam said, “Removing all encroachments and restoring natural drains and lakes to their original form is the solution. ”
He pointed out that even central and state governments have not spared Chennai’s waterways Examples: MRTS on the shores of Buckingham, a highway dividing the Pallikaranai Marshes and an elevated highway