The heavy rain brought on by Cyclone Michaung led to widespread flooding that made life hard for residents of many localities. The northeast monsoon often brings forth intense and copious rain, flooding many areas, mainly the suburbs, for days together. The government and the Greater Chennai Corporation struggle to find a lasting solution to the problem. In times of flooding, volunteers coordinate with civic officials and non-governmental organisations and aid the affected residents. Now, they have come up with an audit that highlights the shortfalls and suggests remedies.
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More rain from southwest monsoon
According to the India Meteorological Department, the city has received more rainfall than the normal 305.5 mm this southwest monsoon: 459.7 mm from June 1 to August 31. As the rain was widespread and not so intense, the Corporation managed the situation without difficulty. But the northeast monsoon is different. And it tests Chennai’s ability to handle torrential rain. In preparation, the Corporation has drafted volunteers from across the city to manage the situation in low-level areas that suffered from clogging and illegal sewage discharge during the floods last year.
The study, Cyclone Michaung 2023-Chennai: Affected Areas and Solutions, was done by volunteers S. Snehasri and Sneha Rajeev. It was submitted to the Corporation on August 16. They were among the volunteers who reached out to the affected people during Cyclone Michaung.
The study points to the deficiencies in infrastructure and socio-economic disparities that complicated the situation in north Chennai during the cyclone and the resultant water stagnation in December last. Ms. Rajeev says teams of volunteers were formed zone-wise, under the aegis of ‘Tamil Nadu Volunteers’, for the audit and for serving as support groups in times of disasters.
A slew of reasons
The study states, “Chennai city once again faced heavy and incessant rainfall on the account of Cyclone Michaung from December 1 to 6, 2023. The Nungambakkam and Meenambakkam observatories recorded 53 cm and 52 cm of rain between December 2 and 4, surpassing the rainfall from December 1 to 3, 2015... Due to a combination of factors, including rapid urbanisation, inadequate storm water drains, and encroachment on waterbodies, flooding occurs recurrently.”
Poor urban planning adds to the problems of inadequate storm water drains, poor waste management, soil degradation, and encroachment on waterbodies, the report states. Residents of Vyasarpadi, Pulianthope, and Thideer Nagar, mostly belonging to vulnerable communities, faced severe hardship — sewage-contaminated floodwaters caused fever and skin infections and the displacement of people, especially those of the Irula community, without shelter, the study says. It says the increase in the prices of essential commodities made them unaffordable for many residents.
Poorly maintained drains
Inadequate provision of storm water drains, due to poor outlay and improper design, and lack of maintenance of the network and missing links contributed to flooding, the study says. The Water Resources Department’s failure to create two recommended reservoirs upstream of the Chembarambakkam Lake aggravated the situation. Incomplete augmentation work across the Kosasthalaiyar and the absence of a law governing flood plain zones continue to make Chennai susceptible to such calamities, it says.
The audit also suggests long- and short-term plans. Short-term plans include equipping volunteers with walkie-talkies and dissemination of information on control rooms and helpline numbers to resolve the issues immediately. It also suggests the creation of a database of hamlets and tribal areas for emergency evacuation and improved relief material inventory tracking. Technological advances such as the Geographic Information System, remote-sensing, and Artificial Intelligence should be leveraged for better risk-mapping, monitoring, and predictive modelling, it says.
Projects to curb degradation
It suggests the establishment of a special purpose vehicle to execute projects to curb environmental degradation and to meet the United Nations’ 17 sustainable development goals. The feedback from the stakeholders must be considered by the government and the civic bodies while they are making budgetary allocations.
The study suggests some long-term plans. Industrial zones should be expanded to other parts of Tamil Nadu so as to reduce unplanned urbanisation and the pressure on the Chennai ports, it says. To enhance water management, it proposes reducing the surface run-off and promoting water infiltration. This involves creation of “floodable areas and detention zones” and of alternative drainage routes.
Green infrastructure
The study also suggests increasing the height of the surface water channels and bioswales (linear, vegetated ditches that allow for collection, conveyance, filtration, and infiltration of storm water). It calls for green infrastructure such as strip plantation along streets, and creation of additional water channels and bioswales. The study recommends amending the law to prevent hoarding and panic-buying in times of crises. Recently, representatives of many departments, MPs, MLAs, and councillors met and discussed the projects to mitigate flooding in the city during the northeast monsoon.
