With the Indian Meteorological Department (IMD) predicting heavy rains for Chennai starting October 15, all eyes are on the city’s preparedness to face potential flooding. The huge amount of rain that the city received, post cyclone-Michaung, had left several parts of the city inundated in December 2023. 

While the Tamil Nadu state government and the Greater Chennai Corporation (GCC) said 13,000 volunteers will be on stand-by, issued advisories, and have brought in boats, trucks for emergency evacuations, flooding risk is a worry for citizens. Storm Water Drain (SWD) works have moved at a slow pace and are pending in several pockets of the city. Some projects that have been completed were damaged by Chennai Metro Rail Limited (CMRL) work while another contributing factor for flooding are drains carrying water into canals and rivers with insufficient capacities.

Although the GCC in November 2023 announced that 92% of the SWD works are complete, even after 11 months, as of October 2024, they remain incomplete. An 82.52 km stretch in the Kosasthalaiyar Basin and 21.36km stretch in the Kovalam basin (phase II) are yet to be completed. The proposed 140km stretch that extends to Kovalam basin under phase III of the SWD project is yet to take off. 

In Thiruvottiyur, located in North Chennai, SWD works are either unfinished or are yet to be linked to canals. Ward 4 councillor Jayaram said, “The work in my ward has been ongoing for the past three years at snail’s pace. In some places they also haven’t linked the drains to the Buckingham canal. Our areas could witness flooding if there is above average rainfall this year.”

SWD works also remain unfinished in Ambattur zone. Councillor of Ward 84, J John told TNM, “There are multiple lakes around this zone including Ambattur lake, Korattur lake and Ayapakkam lake. But storm water drain works are pending in multiple areas. Korattur and Pattravakkam area gets flooded badly every time because the works are incomplete. We were promised last year that channels would be created to divert water to these water bodies but it didn’t happen.” 

TNM, on October 14, visited two places within this ward where SWD works have been ongoing since July. However, the work is only half-way towards completion. The concerned Assistant Engineer (AE) reasoned, “It is more than 5km long and therefore, it took a lot of time to complete works. Now grills are being installed and concrete needs to be laid next. However, if it begins to rain, we will adequately barricade the area to ensure safety.” Several drains in Ambattur zone are also yet to be linked to the Korattur canal, John complained.

SWD work and linking of drains also remain incomplete in isolated pockets of Thiru-Vi-Ka Nagar, Sholinganallur and Teynampet zones.

Incapacitated water channels, canals & rivers

In areas where SWD construction is complete, the fear of canals overflowing and causing flooding looms over the minds of residents. Jai Ganesh, a resident of Kodungaiyur, ward 35, recollected the Kodungaiyur canal overflowing and causing the areas around it to flood severely. “SWD works here were completed except in Block 6. The drain work is almost complete here but the issue is, even with completed drains, we fear that the canal will overflow as it happened in December last year if incessant rains were to lash the city again,” he said.  

Similar fears persist in the Tondiarpet region. For councillor B Vimala (ward 41), being surrounded by incapacitated canals is the main reason for floods. “Although the SWD works are done, we are surrounded by canals - the Buckingham canal, Captain Cotton Canal and the Kodungaiyur canal. The water level in the Buckingham canal seems high already this year,” she told TNM. 

Although the GCC knows such areas are vulnerable if the city witnesses above average rainfall and has provided motors to pump out the water prior to the rains, Arappor Iyakkam convenor and activist Jayaram Venkatesan observed that these measures don’t amount to mitigating floods in the first place. 

“The state and the GCC haven’t learnt any lessons from the December 2023 floods. The government had to take measures to improve the capacities of the channels, canals and rivers to mitigate floods. If not to their original capacity, at least as much as possible, these water bodies should be restored and encroachments be removed if any. But that didn’t happen,” he said. 

He said constructing drains only solves one part of the problem and cited the flooding of Burma Nagar in Manali during the Michaung cyclone as an example. “Last year, Burma Nagar flooded because some corporate giants had encroached the Kosasthalaiyar river. We had pointed this out to the state and had asked them to initiate action and remove encroachments. But that has not been done. If there are heavy rains, the same area will be prone to flooding.”

SWD damaged due to metro rail work

On 25 different stretches in the city, where CMRL work has been ongoing, SWD lines have either partially or fully been damaged. This was found after a joint study by the GCC, IIT-Madras, the disaster management department, CMRL and the Tamil Nadu Road Development Company (TNRDC). While the GCC had said that they will find a solution, councillors from Kilpauk and Purasawalkam areas where the SWD projects have been disrupted said that remedial measures are yet to be undertaken. TNM contacted GCC Commissioner Kumaraguruban for a comment but didn’t receive any response.

Commenting on the issue Arapoor Jayaram said that it is necessary for the state to conduct these studies before beginning the CMRL works. He also pointed out that areas that hadn’t flooded during 2015 Chennai floods were inundated in 2023 after CMRL works were undertaken. “In the Mylapore area, several streets such as Sundareswarar street, that hadn’t flooded in 2015 had water coming in due to metro rail work. Such mistakes on part of the state are costing heavily for the residents,” he added.With the Indian Meteorological Department (IMD) predicting heavy rains for Chennai starting October 15, all eyes are on the city’s preparedness to face potential flooding. The huge amount of rain that the city received, post cyclone-Michaung, had left several parts of the city inundated in December 2023. 

While the Tamil Nadu state government and the Greater Chennai Corporation (GCC) said 13,000 volunteers will be on stand-by, issued advisories, and have brought in boats, trucks for emergency evacuations, flooding risk is a worry for citizens. Storm Water Drain (SWD) works have moved at a slow pace and are pending in several pockets of the city. Some projects that have been completed but were damaged by Chennai Metro Rail Limited (CMRL) work are a cause of concern. Another contributing factor for flooding are drains carrying water into canals and rivers with insufficient capacities.

Although the GCC in November 2023 announced that 92% of the SWD works are complete, even after 11 months, as of October 2024, they remain incomplete. An 82.52 km stretch in the Kosasthalaiyar Basin and 21.36km stretch in the Kovalam basin (phase II) are yet to be completed. The proposed 140km stretch that extends to Kovalam basin under phase III of the SWD project is yet to take off. 

In Thiruvottiyur, located in North Chennai, SWD works are either unfinished or are yet to be linked to canals. Ward 4 councillor Jayaram said, “The work in my ward has been ongoing for the past three years at snail’s pace. In some places they also haven’t linked the drains to the Buckingham canal. Our areas could witness flooding if there is above average rainfall this year.”

SWD works also remain unfinished in Ambattur zone. Councillor of Ward 84, J John told TNM, “There are multiple lakes around this zone including Ambattur lake, Korattur lake and Ayapakkam lake. But storm water drain works are pending in multiple areas. Korattur and Pattravakkam area gets flooded badly every time because the works are incomplete. We were promised last year that channels would be created to divert water to these water bodies but it didn’t happen.” 

TNM, on October 14, visited two places within this ward where SWD works have been ongoing since July. However, the work is only half-way towards completion. The concerned Assistant Engineer (AE) reasoned, “It is more than 5km long and therefore, it took a lot of time to complete works. Now grills are being installed and concrete needs to be laid next. However, if it begins to rain, we will adequately barricade the area to ensure safety.” Several drains in Ambattur zone are also yet to be linked to the Korattur canal, John complained.

SWD work and linking of drains also remain incomplete in isolated pockets of Thiru-Vi-Ka Nagar, Sholinganallur and Teynampet zones.

Incapacitated water channels, canals & rivers

In areas where SWD construction is complete, the fear of canals overflowing and causing flooding looms over the minds of residents. Jai Ganesh, a resident of Kodungaiyur, ward 35, recollected the Kodungaiyur canal overflowing and causing the areas around it to flood severely. “SWD works here were completed except in Block 6. The drain work is almost complete here but the issue is, even with completed drains, we fear that the canal will overflow as it happened in December last year if incessant rains were to lash the city again,” he said.  

Similar fears persist in the Tondiarpet region. For councillor B Vimala (ward 41), being surrounded by incapacitated canals is the main reason for floods. “Although the SWD works are done, we are surrounded by canals - the Buckingham canal, Captain Cotton Canal and the Kodungaiyur canal. The water level in the Buckingham canal seems high already this year,” she told TNM. 

Although the GCC knows such areas are vulnerable if the city witnesses above average rainfall and has provided motors to pump out the water prior to the rains, Arappor Iyakkam convenor and activist Jayaram Venkatesan observed that these measures don’t amount to mitigating floods in the first place. 

“The state and the GCC haven’t learnt any lessons from the December 2023 floods. The government had to take measures to improve the capacities of the channels, canals and rivers to mitigate floods. If not to their original capacity, at least as much as possible, these water bodies should be restored and encroachments be removed if any. But that didn’t happen,” he said. 

He said constructing drains only solves one part of the problem and cited the flooding of Burma Nagar in Manali during the Michaung cyclone as an example. “Last year, Burma Nagar flooded because some corporate giants had encroached the Kosasthalaiyar river. We had pointed this out to the state and had asked them to initiate action and remove encroachments. But that has not been done. If there are heavy rains, the same area will be prone to flooding.”

SWD damaged due to metro rail work

On 25 different stretches in the city, where CMRL work has been ongoing, SWD lines have either partially or fully been damaged. This was found after a joint study by the GCC, IIT-Madras, the disaster management department, CMRL and the Tamil Nadu Road Development Company (TNRDC). While the GCC had said that they will find a solution, councillors from Kilpauk and Purasawalkam areas where the SWD projects have been disrupted said that remedial measures are yet to be undertaken. TNM contacted GCC Commissioner Kumaraguruban for a comment but didn’t receive any response.

Commenting on the issue Arapoor Jayaram said that it is necessary for the state to conduct these studies before beginning the CMRL works. He also pointed out that areas that hadn’t flooded during 2015 Chennai floods were inundated in 2023 after CMRL works were undertaken. “In the Mylapore area, several streets such as Sundareswarar street, that hadn’t flooded in 2015 had water coming in due to metro rail work. Such mistakes on part of the state are costing heavily for the residents,” he added.