Many of Chennai’s recurring flood points are not accidental but rooted in the city’s transformation from a water-rich landscape to a heavily urbanised one.
Published Oct 16, 2025 | 3:31 PM ⚊ Updated Oct 16, 2025 | 3:31 PM
Chennai floods. (Kasturishankar/ X)
Synopsis: Despite the government rolling out elaborate flood-preparedness plans for Chennai, the city still goes underwater when the northeast monsoon arrives. Residents noted that Chennai, once a city of numerous water bodies, now has only a few left, causing water levels to rise after rains.
Every year, the Tamil Nadu government rolls out elaborate flood-preparedness plans for Chennai: Hundreds of pumps, desilted drains, safety checks and public advisories.
Yet, when the northeast monsoon arrives, the city still goes underwater. Streets turn into streams, homes get flooded, and residents are forced to wade through the same old chaos.
Despite taking measures, coordination lapses continue in older neighbourhoods, where incomplete drain works and road digging have left residents facing sewage overflow and stagnant water.
This year, the Greater Chennai Corporation and related departments have stepped up their efforts once again. The civic body has deployed 596 motors and pumps along with 478 vehicles and machinery across its 15 zones.
Chennai Metrowater has hired 50 high-horsepower pumps to manage flooding and sewage issues, while the Metro Rail has placed around 350 pumps across its Phase II construction sites to prevent water stagnation.
The Corporation also identified 120 flood-prone spots, stationed motor and tractor pumps in these areas, and completed 246 kilometres of stormwater drain work, with another 90 kilometres still pending.
Rain-preparedness guidelines have been issued for sanitation and health, with Metrowater stocking alum, bleaching powder and chlorine for purification, and the School Education Department directing institutions to inspect buildings, repair weak structures, and ensure electrical safety before the rains.
Last year, the city followed a nearly identical playbook, according to official records. The Corporation deployed 990 motor pumps, 36 boats, 280 tree-cutting machines, and established 162 relief centres across 15 zones.
Stormwater drain desilting was carried out on 792 kilometres, with an additional 1,152 kilometres targeted for completion. Desilting of 33 waterways spanning 53.42 kilometres was also completed.
From 2021 to 2024, a total of 784.96 kilometres of new stormwater drains were constructed, including 350 kilometres of integrated drains in the Kosasthalaiyar and Kovalam basins. The state government appointed 15 senior IAS officers to oversee flood mitigation and relief measures.
Despite these extensive measures, flooding persisted in several areas, highlighting gaps in execution, maintenance, and coordination.
Uma Vangal, professor and filmmaker, has been a resident of Chennai for six generations and is 60 years old. She explained that Chennai was once a city of lakes, natural water bodies and man-made temple ponds. “There were over 1,450 lakes across the city,” she told South First.
“The names themselves tell the story, Velachery, Adambakkam, Nungambakkam, Perumbakkam, all these areas were once lakes. The houses and temples built around them kept the water bodies desilted and ready for the monsoon, so water would naturally collect in these spaces depending on the slope of the land,” she explained.
Over time, rapid urban development transformed this landscape. Many lake beds, which dried during summer, were built over to create residential plots, gated communities, shopping complexes, office buildings, and IT corridors along East Coast Road (ECR) and Old Mahabalipuram Road (OMR).
Some lakes were retained as reservoirs or eco-parks, but many wetlands disappeared.
“The consequence is clear: Rainwater flows to areas that were originally lakes. Since these spaces are now built over, they flood,” she explained.
She pointed to patterns in flood-prone areas: Locations near the Cooum River, Buckingham Canal, Adyar River, or other areas that were once lakes tend to be the worst affected. For example, Mogappair was once known for its lake, but today it is fully developed, and Velachery, once a large lake, now has only a small portion remaining.
This historical perspective shows that many of Chennai’s recurring flood points are not accidental but rooted in the city’s transformation from a water-rich landscape to a heavily urbanised one.
While the city’s natural landscape once managed water efficiently, Uma Vangal highlighted that modern mismanagement and corruption compound the problem.
“Crores of rupees earmarked for drainage, sewage systems, and stormwater drains often disappear into pockets of contractors or politicians,” she said. “Much of the work is incomplete or never done, yet it is claimed to be finished. The result is large-scale flooding every monsoon.”
She pointed to specific examples: “I live in Railway Nagar, right next to the Cooum River. When the Chembarambakkam and Red Hills reservoirs are opened, everything floods, and boats are stationed at our apartment complex. This is ridiculous because authorities already know which areas are flood-prone. Work on stormwater drains should be completed well ahead of the monsoon.”
Poor urban planning further exacerbates the problem. Low-lying wetlands and marshlands, such as Pallikaranai, have been converted into dump yards or encroached upon by constructions. Drainage projects, even when planned, often fail to integrate with the city’s historical waterways.
“Monsoon flooding is a result of poor planning, haphazard development, and disregard for natural water tables,” she explained and added that, even with flood preparedness measures, the city struggles because the foundation of planning ignores Chennai’s natural landscape and heritage.
On the ground, the reality is clear: South First’s visit to the city’s flood-prone areas showed how vulnerable residents remain during the northeast monsoon.
Residents living near the Adyar River, now largely a stagnant, lifeless canal, describe the northeast monsoon as a period of acute vulnerability.
“The water rises so fast that it enters homes, and people have to wade through it just to move around,” one resident explained. In Saidapet’s slum areas, families live in dilapidated structures that flood easily.
“During the northeast monsoon, the water comes inside, and rats, snakes and other pests appear,” another resident added. Similar conditions have been reported from Thiruvanmiyur and several other low-lying localities, where residents continue to live in unsafe and vulnerable dwellings.
These experiences mirror systemic problems reported recently: In Velachery, Blocked drains forced residents to put up black flags in protest, and in Old Washermenpet, pipeline damage left taps delivering black, foul-smelling water.
While the city rolls out pumps, desilting, and flood alerts, gaps in planning and execution continue to leave many residents at the mercy of the rains.
(Edited by Muhammed Fazil.)
