This post has been self-published on Youth Ki Awaaz by Maithri. Just like them, anyone can publish on Youth Ki Awaaz.

Every Time It Rains, It Gets Flooded. Here’s Why Chennai Floods Frequently.

More from Maithri

This post is part of theYKA Climate Action Fellowship, a 10-week integrated bootcamp to work on stories that highlight the impact of climate change on India’s most marginalized. Click here to find out more and apply.

Although cyclones and heavy rainfalls are normal, their increasing frequency and intensity as well as urban flooding is not.

In the past, Chennai has been witness to many floods and their frequency only seems to be increasing. Some catastrophic years for Chennai vis a vis floods were 1943, 1978, 1985, 2002, 2005, 2015, 2021. According to experts, there are several reasons for rainfall that cause flooding in the city ranging from Chennai’s location itself to climate change. 

Chennai floods
Members of police move in a boat through a water-logged neighbourhood looking for residents to evacuate them to a safer place after heavy rains in Chennai. Photo: Reuters

To understand just why the city floods so frequently, it is important to first understand the city’s ecosystem.

Chennai has a total of three rivers, five wetlands, and six forest areas. The three rivers are Kosathalaiyar, Cooum and Adyar. The five wetlands are Pallikaranai Marsh, Pulicat Lake, Kattupalli Island, Madhavaram & Manali Jheels, Adyar Estuary Creek.

The six forest areas are Huzur Gardens, Vandalur, Guindy National Park, the forests in IIT Madras, Madras Christian College, and Theosophical Society. However, over the course of the years, damage to many parts of this ecosystem, especially the wetlands and rivers, has meant that the city’s natural capabilities to drain water has been compromised.


View this post on Instagram


A post shared by Youth Ki Awaaz (@youthkiawaaz)

#1 Chennai’s Location 

Low-lying areas are places that are essentially just above or at sea level. These areas are more prone to floods. Elevation maps are usually used to map the elevation of locations. Although different areas in Chennai have different elevation levels, the average level of the land in the city is just 2 m above the Mean Sea Level (MSL). Low-lying areas and coastal areas are usually the most affected by flooding due to heavy rainfalls or cyclones. Since Chennai is on flat terrain with several low-lying areas, the water doesn’t get drained easily.

Source: The Hindu

After the 2015 floods, the Tamil Nadu State Disaster Management Authority (TNSDMA) mapped vulnerable areas in Tamil Nadu. They identified 306 flood-prone areas in Chennai and classified them according to their vulnerability.

#2 Northeast Monsoon 

A monsoon means changes in the wind pattern. Monsoon can be accompanied by heavy rainfalls, thunderstorms, and even cyclones. The northeast monsoon essentially represents the direction; it travels from the northeast to the southwest. The northeast monsoon in India usually has its effects in the southern states – Tamil Nadu, Kerala, Andhra Pradesh, some parts of Telangana, and Karnataka during the months of October, November, and December. 

Chennai receives most of its rainfall during the northeast monsoon. The northeast monsoon accounts for 63% of the annual rainfall in Chennai. The city’s normal rain from the entire northeast monsoon is about 87 cm. However, this year, Chennai has already recorded 100 cm of rainfall by November itself. Pradeep John, a weather blogger, who goes by the name Tamil Nadu Weatherman, says 2021 had one of the wettest Novembers for Chennai.

#3 Stormwater Drains (SWDs)

Stormwater drains are drainage systems that are designed and built to drain the excess water from heavy rainfalls and carry them to lakes, ponds, or rivers. It is vital in cities, especially in flood-prone areas to avoid flooding. A good well-connected storm drain system collects the excess water at a low point where water naturally accumulates to avoid flooding. Stormwater drains are normally built on roads of width 7m and above.

A river basin is a piece of land that is dried by the river. Chennai has 4 such river basins – Kosasthalaiyar basin, Kovalam basin, Adyar, and Coovum basin. The Greater Chennai Corporation says that although the city has integrated stormwater drains, the areas consisting of the river basins don’t have integrated stormwater drains. 

Satta Panchayat Iyakkam (SPI), an NGO found out that there was only 1894 km of SWDs against the city’s road stretch of about 5500 km in an RTI reply from October 2018. This essentially means that only 34% of the roads in Chennai are capable of draining water.


View this post on Instagram


A post shared by ZeroSeHero (@zeroseheroyka)

As of January 2021, the SWDs coverage increased to 2,071 km, which is inadequate to drain the city’s water. Of the SWDs present, there were many complaints. Dayanand Krishnan, a Geographic Information System (GIS) consultant told The News Minute that the alignment was improper, leading to an uphill flow (SWDs must be built in such a way that the water flows downhill) after studying the SWDs in T Nagar and Ashok Nagar. He also pointed out that some drains were way too narrow to actually have any meaningful impact. 

The Greater Chennai Corporation (GCC) published a study in January 2021 covering select zones. It’s estimated about 45 km of SWDs are missing. Some have to be constructed again, others demolished and reconstructed. Of the SWD maps published by GCC, 86 out of the 200 wards were missing, which includes the areas Manali, Thiruvotriyur, Sholinganallur, and Perungudi.

Source: The Hindu

In the GCC maps published, many experts pointed out that more details were required. Jayaraman Venkatesan, Convenor of Arappor Iyakkam stated that more information like the gradients, disposal points, year of construction would be required to identify gaps and perform a detailed analysis.


View this post on Instagram


A post shared by ZeroSeHero (@zeroseheroyka)

#4 Encroachment 

The rampant urbanization eventually led to encroachment near water bodies. Up until 1990, the build-up area stayed clear from waterbodies. However, the later build-ups were in areas near water bodies, in low-lying areas, leading to flooding and waterlogging. 

The Pallikaranai marshland shrunk from 13,500 acres in 1972 to 1,500 acres in 2020. Ramsar site is a wetland of international significance. Tamil Nadu is calling for the declaration of the Pallikaranai as a Ramsar site. Pulicat Lake, the second-largest coastal lagoon in India was measured 3.8 m in depth at 1610. By 2017, it was reduced to just 0.8 m. The Adyar and Coovum river has been reduced to dumping waste and carrying sewage through the city.

There have been restoration efforts. The Chennai River Restoration Trust (CRRT) has been coordinating with various departments to restore the river. It showed substantial results as the water spread of the creek increased from 5% to 59%. 

Nityanand Jayaraman is an activist and writer from Chennai who pointed out the encroachment via a tweet that showed the encroachment using a map of Velachery. 

The scroll compared the maps from the 1900s to the present day maps to show that some water bodies have completely disappeared


#5 Climate Change 

The Council on Energy, Environment and Water (CEEW) performed a first-of-its-kind district-level climate vulnerability assessment. They analyzed 640 districts to assess their vulnerabilities to extreme weather events like cyclones, floods, heatwaves, droughts, etc. Chennai was ranked seventh in their vulnerability assessment because the city is prone to extreme weather conditions like cyclones and floods.

A modeling study by the researchers of the Indian Institute of Technology (IIT) found correlations between the increasing carbon emissions and extreme rainfall. The model made projections for the year 2075, that the precipitation on a peak rainy day can increase by 17.37%. 

The 2015 Chennai floods caught the attention of people worldwide. French Foreign Minister Laurent Fabius expressed his solidarity for the people in Chennai and called for “concrete and urgent action against climate disruption.”

Featured image is for representational purposes only.
You must be to comment.

More from Maithri

Similar Posts

By Tarun

By Saurabh Gandle

By Ankur Tripathi

    If you do not receive an email within the next 5 mins, please check your spam box or email us at

      If you do not receive an email within the next 5 mins, please check your spam box or email us at

        If you do not receive an email within the next 5 mins, please check your spam box or email us at

        Wondering what to write about?

        Here are some topics to get you started

        Share your details to download the report.

        We promise not to spam or send irrelevant information.

        Share your details to download the report.

        We promise not to spam or send irrelevant information.

        An ambassador and trained facilitator under Eco Femme (a social enterprise working towards menstrual health in south India), Sanjina is also an active member of the MHM Collective- India and Menstrual Health Alliance- India. She has conducted Menstrual Health sessions in multiple government schools adopted by Rotary District 3240 as part of their WinS project in rural Bengal. She has also delivered training of trainers on SRHR, gender, sexuality and Menstruation for Tomorrow’s Foundation, Vikramshila Education Resource Society, Nirdhan trust and Micro Finance, Tollygunj Women In Need, Paint It Red in Kolkata.

        Now as an MH Fellow with YKA, she’s expanding her impressive scope of work further by launching a campaign to facilitate the process of ensuring better menstrual health and SRH services for women residing in correctional homes in West Bengal. The campaign will entail an independent study to take stalk of the present conditions of MHM in correctional homes across the state and use its findings to build public support and political will to take the necessary action.

        Saurabh has been associated with YKA as a user and has consistently been writing on the issue MHM and its intersectionality with other issues in the society. Now as an MHM Fellow with YKA, he’s launched the Right to Period campaign, which aims to ensure proper execution of MHM guidelines in Delhi’s schools.

        The long-term aim of the campaign is to develop an open culture where menstruation is not treated as a taboo. The campaign also seeks to hold the schools accountable for their responsibilities as an important component in the implementation of MHM policies by making adequate sanitation infrastructure and knowledge of MHM available in school premises.

        Read more about his campaign.

        Harshita is a psychologist and works to support people with mental health issues, particularly adolescents who are survivors of violence. Associated with the Azadi Foundation in UP, Harshita became an MHM Fellow with YKA, with the aim of promoting better menstrual health.

        Her campaign #MeriMarzi aims to promote menstrual health and wellness, hygiene and facilities for female sex workers in UP. She says, “Knowledge about natural body processes is a very basic human right. And for individuals whose occupation is providing sexual services, it becomes even more important.”

        Meri Marzi aims to ensure sensitised, non-discriminatory health workers for the needs of female sex workers in the Suraksha Clinics under the UPSACS (Uttar Pradesh State AIDS Control Society) program by creating more dialogues and garnering public support for the cause of sex workers’ menstrual rights. The campaign will also ensure interventions with sex workers to clear misconceptions around overall hygiene management to ensure that results flow both ways.

        Read more about her campaign.

        MH Fellow Sabna comes with significant experience working with a range of development issues. A co-founder of Project Sakhi Saheli, which aims to combat period poverty and break menstrual taboos, Sabna has, in the past, worked on the issue of menstruation in urban slums of Delhi with women and adolescent girls. She and her team also released MenstraBook, with menstrastories and organised Menstra Tlk in the Delhi School of Social Work to create more conversations on menstruation.

        With YKA MHM Fellow Vineet, Sabna launched Menstratalk, a campaign that aims to put an end to period poverty and smash menstrual taboos in society. As a start, the campaign aims to begin conversations on menstrual health with five hundred adolescents and youth in Delhi through offline platforms, and through this community mobilise support to create Period Friendly Institutions out of educational institutes in the city.

        Read more about her campaign. 

        A student from Delhi School of Social work, Vineet is a part of Project Sakhi Saheli, an initiative by the students of Delhi school of Social Work to create awareness on Menstrual Health and combat Period Poverty. Along with MHM Action Fellow Sabna, Vineet launched Menstratalk, a campaign that aims to put an end to period poverty and smash menstrual taboos in society.

        As a start, the campaign aims to begin conversations on menstrual health with five hundred adolescents and youth in Delhi through offline platforms, and through this community mobilise support to create Period Friendly Institutions out of educational institutes in the city.

        Find out more about the campaign here.

        A native of Bhagalpur district – Bihar, Shalini Jha believes in equal rights for all genders and wants to work for a gender-equal and just society. In the past she’s had a year-long association as a community leader with Haiyya: Organise for Action’s Health Over Stigma campaign. She’s pursuing a Master’s in Literature with Ambedkar University, Delhi and as an MHM Fellow with YKA, recently launched ‘Project अल्हड़ (Alharh)’.

        She says, “Bihar is ranked the lowest in India’s SDG Index 2019 for India. Hygienic and comfortable menstruation is a basic human right and sustainable development cannot be ensured if menstruators are deprived of their basic rights.” Project अल्हड़ (Alharh) aims to create a robust sensitised community in Bhagalpur to collectively spread awareness, break the taboo, debunk myths and initiate fearless conversations around menstruation. The campaign aims to reach at least 6000 adolescent girls from government and private schools in Baghalpur district in 2020.

        Read more about the campaign here.

        A psychologist and co-founder of a mental health NGO called Customize Cognition, Ritika forayed into the space of menstrual health and hygiene, sexual and reproductive healthcare and rights and gender equality as an MHM Fellow with YKA. She says, “The experience of working on MHM/SRHR and gender equality has been an enriching and eye-opening experience. I have learned what’s beneath the surface of the issue, be it awareness, lack of resources or disregard for trans men, who also menstruate.”

        The Transmen-ses campaign aims to tackle the issue of silence and disregard for trans men’s menstruation needs, by mobilising gender sensitive health professionals and gender neutral restrooms in Lucknow.

        Read more about the campaign here.

        A Computer Science engineer by education, Nitisha started her career in the corporate sector, before realising she wanted to work in the development and social justice space. Since then, she has worked with Teach For India and Care India and is from the founding batch of Indian School of Development Management (ISDM), a one of its kind organisation creating leaders for the development sector through its experiential learning post graduate program.

        As a Youth Ki Awaaz Menstrual Health Fellow, Nitisha has started Let’s Talk Period, a campaign to mobilise young people to switch to sustainable period products. She says, “80 lakh women in Delhi use non-biodegradable sanitary products, generate 3000 tonnes of menstrual waste, that takes 500-800 years to decompose; which in turn contributes to the health issues of all menstruators, increased burden of waste management on the city and harmful living environment for all citizens.

        Let’s Talk Period aims to change this by

        Find out more about her campaign here.

        Share your details to download the report.

        We promise not to spam or send irrelevant information.

        A former Assistant Secretary with the Ministry of Women and Child Development in West Bengal for three months, Lakshmi Bhavya has been championing the cause of menstrual hygiene in her district. By associating herself with the Lalana Campaign, a holistic menstrual hygiene awareness campaign which is conducted by the Anahat NGO, Lakshmi has been slowly breaking taboos when it comes to periods and menstrual hygiene.

        A Gender Rights Activist working with the tribal and marginalized communities in india, Srilekha is a PhD scholar working on understanding body and sexuality among tribal girls, to fill the gaps in research around indigenous women and their stories. Srilekha has worked extensively at the grassroots level with community based organisations, through several advocacy initiatives around Gender, Mental Health, Menstrual Hygiene and Sexual and Reproductive Health Rights (SRHR) for the indigenous in Jharkhand, over the last 6 years.

        Srilekha has also contributed to sustainable livelihood projects and legal aid programs for survivors of sex trafficking. She has been conducting research based programs on maternal health, mental health, gender based violence, sex and sexuality. Her interest lies in conducting workshops for young people on life skills, feminism, gender and sexuality, trauma, resilience and interpersonal relationships.

        A Guwahati-based college student pursuing her Masters in Tata Institute of Social Sciences, Bidisha started the #BleedwithDignity campaign on the technology platform, demanding that the Government of Assam install
        biodegradable sanitary pad vending machines in all government schools across the state. Her petition on has already gathered support from over 90000 people and continues to grow.

        Bidisha was selected in’s flagship program ‘She Creates Change’ having run successful online advocacy
        campaigns, which were widely recognised. Through the #BleedwithDignity campaign; she organised and celebrated World Menstrual Hygiene Day, 2019 in Guwahati, Assam by hosting a wall mural by collaborating with local organisations. The initiative was widely covered by national and local media, and the mural was later inaugurated by the event’s chief guest Commissioner of Guwahati Municipal Corporation (GMC) Debeswar Malakar, IAS.

        Sign up for the Youth Ki Awaaz Prime Ministerial Brief below