Climate change is leading to rising sea levels and floods in some cities and rising floods in others and droughts and water shortages in others. For Chennai’s 11 million residents, it is both.
The sixth largest city in India receives an average of 1,400 mm (55 in) of rain a year, which is twice that of London and almost four times the level of Los Angeles. Yet in 2019, it made headlines for being one of the first big cities in the world – driving trucks with 10 million liters of water a day to hydrate its population. This year, it was the fastest January in decades.
The ancient South Indian port has become a case study in which it can go wrong when industrialization, urbanization and extreme weather converge and develop a metropolis on its floodplain to meet the demand for new homes, factories and offices.
Formerly called Madras, Chennai sits on a low plain on the southeastern coast of India, surrounded by three main rivers, all heavily polluted, which flow into the Bay of Bengal. For centuries it has been a trade link connecting the gateways to the near and far east and south India. Its success led to a plan, which grew with the scare scheme and now houses more people than Paris, many of which are thriving in the auto, healthcare, IT and film industries.
But its geography is also its weakness.
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The water of the Bay of Bengal cyclone keeps increasing in the city from time to time, causing the rivers filled with sewage to flow on the roads. Rainfall is uneven in November and December with the northeast falling up to 90% during the monsoon season. When the rains fail, the city must rely heavily on desalination plants and water from hundreds of kilometers away because most of its rivers and lakes are heavily polluted.
While climate change and extreme weather have played a role, poor planning is the main culprit for Chennai’s water crisis. As the city grew, vast areas of the surrounding flood zones disappeared with their lakes and ponds. Between 1893 and 2017, according to researchers at Chennai’s Anna University, the area of Chennai’s water bodies shrunk from 12.6 square kilometers to about 3.2 square kilometers. Much of that loss was in the last few decades, including the construction of the city’s famous IT corridor in 2008 on approximately 230 square kilometers of marshland. The Anna University team has estimated that by 2030 about 60% of the city’s groundwater will be severely degraded.
Floods increased due to rain at low places. In 2015, Chennai suffered its worst floods in a century. The northeast monsoon received 494 mm (19.4 inches) of rain in a single day in the city. More than 400 people died in the state and 1.8 million people came out of their homes. In the IT corridor, water reached the second floor of some buildings.
Four years later, it was the scarcity of water that made headlines. The city drained all of its main reservoirs as de gyro, forcing the government to truck in drinking water. People lined up for hours to fill containers, water tankers were set up and violence erupted in some areas.
Writer and environmental activist Nityananda Jayaraman, who lives in Chennai, said, “The roots of flooding and water scarcity are the same: urbanization and construction in an area, according to natural boundaries”. “The two most powerful agents of politics and business are visions that are rarely seen. We are doomed until change happens. “
Tamil Nadu, the state capital of Chennai in its Climate Change Action Plan, predicts that the average annual temperature will rise 3.1 degrees Celsius from 1970–2000 levels to 2100, while annual rainfall will fall by 9%. Worse still, precipitation during the southwest monsoon of June – September, which usually brings the steady rain needed to grow crops and fill reservoirs, will decrease, while the flood-cyclone season is more intense in winter. Will go. This can mean bad floods and droughts.
The northeast monsoon officially ends in December, but this winter continued with good rain in January, with Tamil Nadu receiving 10 times more rain than normal for the month.
Arun Krishnamurthy, founder of the Chennai-based non-profit Environmentalist Foundation of India, said, “When my parents and grandparents were young, such heavy rains were not common.” “People talk a lot about weird weather here, but they don’t relate it to climate change.”
Chennai is an extreme example of a problem that is rapidly disrupting cities around the world that are also grappling with a rapidly growing population. Sao Paulo, Beijing, Cairo and Jakarta are among the urban centers facing severe water shortages. Krishnamurthy said, “This is a global problem, not just Chennai.” “We need to work together to ensure that we have a water-safe future.”
The Tamil Nadu government says it is solving the problem. In 2003, it passed a law requiring all buildings to store rainwater. According to the Central Ground Water Board of the Ministry of Agriculture, the rule helped raise the water table, but the benefit was soon erased by lack of maintenance. Groundwater recharge efforts have also struggled to offset the amount of water being drained through the borehole.
The Chennai Metropolitan Water Supply and Sewerage Board did not answer questions about the issue. The Tamil Nadu Water Supply and Drainage Board did not respond to an e-mail seeking comments.
Shortly after Day Zero of 2019, Tamil Nadu Chief Minister Adapadi Palaniswamy announced a public program that would include “massive participation of women” in all manner of studies ranging from rainwater harvesting, water saving and recycling and conservation of water resources Are included. Polluted rivers of the state.
Until that time, the government’s strategy centered around building large desalination plants, an expensive strategy typically associated with limited freshwater in arid countries or islands. The plants have been criticized for causing environmental damage and for having a negative impact on local fisheries.
Now, the government is adopting a new approach inspired by the city’s past. The Greater Chennai Corporation is supporting an initiative called City of 1000 Tanks, a reference to ancient man-made lakes that were built around the temples.
Supported by the Dutch government and the Asian Infrastructure Investment Bank, the plan is to restore some temple tanks and to build hundreds of new ones along the green slopes across the city to absorb and filter heavy rains, recharge groundwater and use during droughts Have to store water. Month.
“Flood, drought and sanitation are all interlinked,” said Sudhindra NK, director of Madras terrace architectural works. “When an important mass of people picks it all up, a significant difference will be noticed and we will no longer be in trouble.” He said that it would take at least 5 years for the project to be affected.
Meanwhile, Chennai continues to add a quarter of a million people per year, racing against time to prevent flooding and water scarcity.
Krishnamurthy said, “My fear will be more on these things in future.” “We did not learn a lesson from de Ziro.” – by Anurag Kotoki and Karolyn Kahn
– assisted by Ganesh Nagarajan, Jodi Megson and Jin Woo