Chennai, formerly called, Madras is India’s sixth largest city with a population of about 11 million. On an average, the city gets an average of about 1,400mm of rainfall in a year. However, climate change effects are being observed with rising sea levels, increased flooding, and drought and water shortages in Chennai. It has led to a major water crisis for its inhabitants. Convergence of various factors including industrialisation, urbanisation, and extreme weather conditions have also contributed to this crisis. Wrong planning of this ancient south Indian port city of Chennai, which is a significant economic, political, and cultural centre, has sacrificed its flood plains to satisfy demands for new homes, offices, and factories.
Chennai’s Location
Chennai is situated on a low plain on the southeast coast of India. The city is intersected by its three main rivers-the Kosasthalaiyar to the north, the Adyar river to the south, and the Cooum (also spelt ‘coovum’) flowing between them across central Chennai. The three rivers are connected by the Buckingham canal, built in the 19th century for navigational purposes. All the three rivers are heavily polluted and they drain into the Bay of Bengal. Chennai has been a trading link connecting the near and far east and a gateway to South India. Its success brought forth a large and famous metropolitan city. The planning of the city is inadequate and people from various walks of life including auto, healthcare, IT, film industry, etc., have settled here for their livelihood. However, the geography of Chennai is also its weakness.
Reason for Water Crisis in Chennai
The rainfall in Chennai is uneven. Up to 90 per cent of the rainfall happens during the northeast monsoon season in the months of November and December. The cyclone-prone waters of the Bay of Bengal sometimes flow into the city. This leads to the overflow of sewage-filled rivers into the streets.
Apart from climate change and extreme weather, the main culprit for Chennai’s water woes is the poor planning of the city. As the city expanded, vast area of the surrounding flood plain along with the lakes and ponds disappeared. Buildings kept cropping in the areas where the lakes and ponds once existed. Researchers of the Anna University, Chennai, state that between 1893 and 2017, the area of Chennai’s water bodies shrank from 12.6 square kilometres to about 3.2 square kilometres. Most of that loss was in the past few decades. Chennai’s famous IT corridor was constructed in 2008 on about 230 square kilometres. This corridor was built on a large area of marshland. This severely reduced the capacity of the city’s last remaining urban wetland to recharge the groundwater. The Anna University research team projects that by the year 2030, around 60 per cent of Chennai’s groundwater would be critically degraded.
Presently, there are only a few places that can hold precipitation as flooding has increased. Chennai suffered its worst inundation in the year 2015. The northeast monsoon in 2015 brought 494mm of rain to the city in a single day. This disaster led to a casualty of more than 400 people in the state and around 1.8 million people were flooded out of their homes. The IT corridor, built on marshland, was also flooded with water which reached up to the second floor of some buildings.
In the year 2019, the city of Chennai faced shortage of water, and hit ‘Day Zero’, when all its main reservoirs including PoondiCholoavaram lake, Redhills lake, and Chembarambakkam lake ran dry. The administration had to truck in 10 million litres a day to hydrate its population. Chennai is one of the cities in the world, which is grappling with rapid increase in population and facing severe water scarcity. According to experts, the reason for scarcity of water in Chennai, despite monsoon is rapid urbanisation and unplanned construction in wetlands to accommodate politics and business.
Climate Change Predictions
It is predicted that the average annual temperature of Chennai is expected to rise by 3.1°C by 2100. This is based on the study of the pattern of climatic change from the year 1970 to 2000 levels. The study also stated that the annual rainfall would be as much as 9 per cent. It is predicted that rainfall during the southwest monsoon, during June to September, would reduce. This would have an adverse impact in growing crops and refilling reservoirs. The flood-prone cyclone season in the winter would become more intense. This would lead to worse floods and droughts in Chennai. In 2020 too, the northeast monsoon, which was supposed to officially end in December, continued till January 2021 with Tamil Nadu receiving more than 10 times the normal rainfall in the month. This is an impact of climate change.
Actions and Plans to Secure Water and Its Resources in Chennai
The population of Chennai needs to work together to secure water for future. The Tamil Nadu government says that it is addressing the problem. In the year 2003, it passed a law requiring all buildings in Chennai to harvest rainwater. According to the Ministry of Agriculture’s Central Ground Water Board, though the rule helped raise the water table, the results of harvesting rain water soon eroded due to lack of maintenance. The government administration is struggling to offset the volume of water being extracted through boreholes.
Initially, the government had a strategy for construction of large desalination plants. However, it turned out to be an expensive affair. These plants also have been criticised for causing environmental damage. Further, these plants have also had a negative impact on local fisheries.
After the Day Zero in 2019, the Government of Tamil Nadu had announced a public programme including massive participation of women. This programme included covering everything from rainwater harvesting, water saving, and the recycling and protection of water resources. The programme also had classes on how to clean up the polluted rivers of the state.
In November 2020, Chennai got its fifth reservoir, Kannankottai-TherovyKandigai after a gap of 76 years, to improve the water supply to the city. The reservoir would facilitate supply of 65 million liters of water per day to the city.
Now the government is also trying to stick to the basics and pursue the approaches followed in the past. The Greater Chennai Corporation is supporting an initiative called the ‘City of Thousand Tanks’. This initiative aims to refurbish and renew the ancient man-made lakes that were built around ancient temples.
The Tamil Nadu government, with the support from the Dutch Government and the Asian Infrastructure Investment Bank, has made schemes to restore temple tanks. The draft plan is to restore some temple tanks and build hundreds of new ones with green slopes throughout the city. This is to absorb and filter heavy rains, recharge the groundwater, and store water for use during dry months.
Experts from Madras Terrace Architectural Works who are involved in this project say that floods, drought and sanitation are all interlinked. When a critical mass of people, who are dedicated take up this initiative seriously, then the difference could be noticed sooner than later. However, it would at least take five years for the project to have an impact.
Conclusion
Despite all the efforts and initiatives, it is going to be a race against time to curb the floods and water shortages of Chennai. This is because the city continues to add a quarter of a million people every year and the administration has to cater to their requirement of water.
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