How a water crisis hit Chennai in India – one of the world’s wettest cities

Climate change is bringing rising sea levels and rising floods to some cities around the world and drought and water shortages for others. For the 11 million inhabitants of Chennai, it’s both.

India’s sixth largest city receives an average of about 1400 mm (55 inches) of rainfall per year, more than twice the amount that falls on London and almost four times the level of Los Angeles. Yet in 2019, it made headlines because it was one of the first major cities in the world to no longer have water – it transported 10 million gallons a day to hydrate the population. This year it had the wettest January in decades.

The ancient South Indian port has become a case study of what could go wrong as industrialization, urbanization and extreme weather converge and a thriving metropolis across its floodplain paved to meet the demand for new homes, factories and offices.

Formerly known as Madras, Chennai sits on a low plain on the southeast coast of India, crossed by three major rivers, all heavily polluted, flowing into the Bay of Bengal. It was for centuries a trade link connecting the Near and Far East and a gateway to South India. Its success has continued to build in a neighborhood that has grown with little planning and now houses more people than Paris, many of whom are engaged in thriving automotive, healthcare, IT and film industries.

But its geography is also its weakness.

The cyclone-sensitive waters of the Bay of Bengal occasionally push into the city, forcing the sewer-rich rivers back into the streets. Rainfall is uneven, with up to 90% during the northeast monsoon season in November and December. When rain fails, the city has to rely on huge desalination plants and water that is carried hundreds of miles away because most rivers and lakes are too polluted.

While climate change and extreme weather have played a role, the poor blame for Chennai’s water problems is poor planning. As the city grew, vast areas of the surrounding floodplain, along with its lakes and dams, disappeared. Between 1893 and 2017, the surface area of ​​Chennai’s water bodies shrank from 12.6 square kilometers to about 3.2 square kilometers, according to researchers from Anna University in Chennai. Most of the loss has been over the past few decades, including the construction of the city’s famous IT corridor in some 230 square kilometers of marshland. The team of the University of Anna plans that by 2030 about 60% of the groundwater in the city will be critically degraded.

With fewer places to hold precipitation, floods have increased. In 2015, Chennai experienced the worst flooding in a century. The northeast monsoon rained as much as 494 mm (19.4 inches) of rain on the city in one day. More than 400 people in the state have died and 1.8 million have been flooded from their homes. In the IT corridor, water reached the second floor of some buildings.

Four years later, there was a shortage of water that made headlines. The city hit Zero the day all its main reservoirs ran dry, forcing the government to load drinking water. People queued for hours to fill containers, water tankers were hijacked and violence broke out in some neighborhoods.

“Floods and water scarcity have the same roots: urbanization and construction in an area without the natural limits of the place,” said Nityanand Jayaraman, a writer and environmental activist living in Chennai. “The two most powerful changes – politics and business – have visions that are too short-sighted. Unless that changes, we are doomed. ”

Tamil Nadu, the state where Chennai is the capital, predicts in its action plan for climate change that the average annual temperature will rise by 3.1 ° C by 2100 from 1970-2000 levels, while the annual rainfall will fall by as much as 9% . Worse, precipitation during the southwestern June-September monsoon, which usually brings with it the steady rains needed to grow crops and fill storage dams, will diminish, while the flood-prone cyclone season will intensify in winter. This can mean worse floods and droughts.

The northeast monsoon officially ends in December, but this winter the heavy rains continued until January, with Tamil Nadu receiving more than ten times the normal rainfall for the month.

“Such rainfall was not normal when my parents and grandparents were young,” said Arun Krishnamurthy, founder of the Chennai-based nonprofit Environmentalist Foundation of India. “People here talk a lot about the strange weather, but they do not link it to climate change.”

Chennai is a prime example of a problem that is increasingly disrupting cities around the world that are also struggling with rapid population growth. Sao Paulo, Beijing, Cairo and Jakarta are among urban centers experiencing severe water scarcity. “This is a global problem, not just Chennai,” Krishnamurthy said. “We need to work together to ensure we have a water-safe future.”

The Tamil Nadu government says it is addressing the issue. In 2003, it passed a law requiring all buildings to harvest rainwater. The rule helped raise the water table, but the gains were soon eroded by a lack of maintenance, according to the Central Groundwater Board of the Ministry of Agriculture. Attempts to load groundwater have also struggled to compensate for the amount of water extracted through boreholes.

The Metropolitan Water Supply and Sewerage Board in Chennai did not respond to questions about the issue. The Tamil Nadu Water Supply and Drainage Board did not respond to a request for comment.

Shortly after 2019’s Day Zero, Edappadi Palaniswami, Prime Minister of Tamil Nadu, announced a public program that will include a “massive participation of women”, which includes everything from rainwater harvesting, water conservation and the recovery and protection of water resources, together with studies on how to clean up the polluted rivers of the state.

Until then, the government’s strategy has focused on setting up large desalination plants, an expensive tactic usually associated with arid lands or islands with limited fresh water. The plants have been criticized for causing environmental damage and adversely affecting local fisheries.

Now the government is following a new approach inspired by the city’s past. The Greater Chennai Corporation supports an initiative called City of 1,000 Tanks, a reference to the ancient man-made lakes built around temples.

Supported by the Dutch government and the Asian Infrastructure Investment Bank, the plan is to repair temple tanks and build hundreds of new ones with green slopes in the city to absorb and filter heavy rain, recharge groundwater and store water for use during drought months.

“Floods, droughts and sanitation are interconnected,” said Sudheendra NK, director of Madras Terrace Architectural Works, which is involved in the project. “If a critical mass of people take it all in, a significant difference will be noticed and we will no longer be in a crisis.” He said it would take at least five years before the project had an impact.

Meanwhile, Chennai continues to add a quarter of a million people a year, making it a race against time to curb the floods and water shortages.

“I fear these things will happen more frequently in the future,” Krishnamurthy said. ‘We did not learn the lesson from’ Day Zero ‘. ” – By Anurag Kotoky and Karoline Kan

– Assisted by Ganesh Nagarajan, Jody Megson and Jin Wu