Vulnerable to freak floods: Is your city the next Chennai?

  • Hindustan Times, HT Bureaus
  • Updated: Dec 13, 2015 14:23 IST
File photo of people travelling on a boat as they move to safer places through a flooded road in Chennai. (REUTERS)

Each succeeding year seems to bring with it a fresh natural disaster of epic proportions. We watch horror-struck as the scenes of destruction flicker on our television screens and resort to fervent prayer in the absence of any indication that earthly forces will help sort out these problems. This is strange considering that, regardless of climate change, many of the disasters striking the subcontinent — the latest being the rains that left Chennai submerged — have been compounded by a disastrous set of factors: haphazard town planning, choked drains, poor garbage management, and the rampant destruction of mangroves, forests and pastures that could act as a buffer and a natural drain.

Our cities with their high population density and poor civic standards are vulnerable to the domino effect that can be set off by freak weather — it happened in Mumbai in 2005. Last year, it was Srinagar. Now it’s happening in Chennai. Could it happen to your city? Judging by the burgeoning urban population, and the uncontrolled growth of urban centres that fail on every parameter including drainage and garbage disposal, most of our cities are disasters waiting to happen.

“Depending on the geographical location, each city has a different cause that makes it vulnerable to a Chennai-like situation. But there are a few common factors, such as neglect of water bodies and inappropriate development along estuaries,” says KT Ravindran, urban designer and dean emeritus, RICS School of Built Environment.

Disastrous drains

Things look bad even for planned cities like Corbusier’s Chandigarh, which had what was considered, until two decades ago, India’s best drainage. Now, the pavement area in the city has increased leading to an overloading of the drainage system. New Delhi’s drains too are definitely not capital.

“Delhi’s floodplains have been concretised and unchecked construction is happening on them,” said water activist, Manoj Misra. “The covered storm water drains in Defence Colony, AIIMS and Lajpat Nagar are an invitation to disaster because rain water cannot enter them.”

For a city located on the Sangam, Allahabad’s drainage is woefully inadequate. A significant number of its 210 deep open drains and 115 roadside drains have been encroached upon. Chief Town Planner PK Solanki believes the situation could turn dangerous if the city received more than average rainfall. Bhubaneswar too once had a good drainage system but is now experiencing problems. “Over the years, the natural streams became a casualty to rampant construction activities. Drains are supposed to carry rain water not sewerage,” says planner Piyush Kumar Rout. The settlements in low-lying areas of the city suffered waterlogging after heavy rain in 2012, 2013 (during Cyclone Phailin) and in 2014. In 2013, in several colonies, people had to be evacuated from their houses with the help of boats. Mayor Anant Jena, however, stresses that the city is fully equipped to deal with rain and that Bhubaneswar will soon have 40 pumping stations and five sewerage treatment plants.

Even a new city like Amravati, Andhra Pradesh’s future capital, seems doomed. AP CM Chandrababu Naidu, who dreams of making it a world class capital needs to be cautious as the city will come up on 30,000 acres of farm land interspersed with a stream and smaller water channels. “The Amaravati capital city project, as it is being planned now, will expose the new city to the risk of Chennai-like floods, as large stretches of the proposed urban agglomeration there contain paleo-channels. Any large scale construction activity over those stretches will cause devastating floods whenever cloudbursts occur,” says environmentalist and former finance secretary to the government of India, EAS Sarma.

A look at a few cities that are on the brink of a possible crisis and the problems they are grappling with.

Population pressure

Our burgeoning population and the resultant pressure on infrastructure could shoulder some of the blame. Chandigarh was planned for a population of 5 lakhs, but is now home to 11 lakh people. Allahabad, which had a population of 14.96 lakh as per the 2011 census, is expected to see the figure rise to 20.50 lakh by 2021. Jaipur too has grown in the last decade — the population rose 26.19 per cent between 2001 and 2011. It now stands at 6.62 million. Nowhere is population pressure as evident as in the national capital. From 400,000 in 1901, the population of Delhi increased to around 18,248,290 in 2015. According to the last census, Delhi has a population of 16,753,235. This figure is set to rise by 40 per cent by 2020. The waste generated and pressure on the existing drains will increase accordingly. KT Ravindran insists the problem is not really the increasing population. “There is a fundamental inadequacy in the way we look at urban planning,” he says.

No dodging disaster

Jaipur was flooded most recently in 2012. The civic authorities struggled to cope but eventually the army had to be called in. Even Bengaluru has had its nightmare moments. In 2005, rains caused massive flooding in many parts of the IT corridor. A study found that the disappearance of lakes was to blame. There were 51 lakes in the heart of the city in 1985; today there are only 17. A field survey by environmental scientists Anil Gupta and Sreeja Nair in 2007 found that 66 per cent of all remaining lakes were being pumped with sewage and 72 per cent had lost all their catchment area.

India’s crisis calender

Nature fights back

According to a report from Climate Central a US-based research organization, Kolkata along with Mumbai are among the top 10 megacities across the world that faces a serious threat due to rising sea levels owing to climate change. Kolkata has an elaborate underground sanitation network. “But there is a limit. There won’t be any waterlogging if it rains at the rate of less than 10 mm per hour. If the rain is more, there would be waterlogging,” said Tarak Singh member-mayor-in-council (drainage and sewerage) of Kolkata Municipal Corporation.

The civic body over the past few years has taken a series of steps including the construction of new pumping stations, increasing the number of portable pumps and dredging of canals to improve the system. The city’s bowl shape and the fact that its lock gates cannot be opened when the rising water level coincides with high tide causes waterlogging.

More worrying is the disappearance of the city’s green cover. Recent satellite pictures show it has dipped to less than five per cent. The East Kolkata Wetlands are considered as the city’s natural kidneys because they treat the city’s sewage naturally. It also acts as huge carbon sink. But this is being gradually filled up.

The greatest threat will come from the Sunderbans, which provides the first level of protection from cyclones that originate in the sea. The mangrove acts like a sponge. But with increasing salinity, rising sea levels and the illegal felling of mangroves, experts feel most of the Sunderbans would degrade into less dense open mangrove by 2050. Sushmita Sengupta, deputy programme manager, Centre for Science and Environment believes erratic rainfall and the loss of wetlands are the main reasons that put cities at risk. “The issue of climate change and erratic rainfall is a separate one. But cities that are at high-risk are the ones that have lost huge wetland areas. Whether you look at the 2005 Mumbai floods or the 2014 Srinagar floods or the most recent one in Chennai, these are cities traditionally known for their wetlands, but have lost them in recent years. There is a disconnect between urban planning and the hydro-geological cycle. We need stronger wetland protection laws. Planners tend to value the land and not the water that is there in the land,” she says.

Unless we take immediate action, India’s cities are staring at a bleak future indeed.

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