In 2013, a multi-day cloudburst in Uttarakhand caused devastating floods, killing more than 5,000 people. A year later, Kashmir suffered disastrous deluge due to torrential rainfall. Thousands were displaced and more than 500 people were killed on both sides of Kashmir. At the end of 2015, Chennai had its brush with an equally catastrophic flood that paralysed the city. 2016 saw Assam and Madhya Pradesh grapple with the reality that floods of massive intensity have become the new normal for India.
While it is convenient to push the blame to extreme weather events for unprecedented rains, but not all of it is of nature’s doing. For instance, rains could cause so much havoc in Uttarakhand because the state had already witnessed indiscriminate developmental activities carried out in the ecologically fragile regions of the state. Chennai, which is no stranger to cyclonic storms and heavy rains, especially during the annual northeast monsoon in November–December, saw the worst flood in its history. In its bid to expand, the city has been encroaching upon its rivers, sacrificing wetlands to accommodate development and eating into the marshlands for developing public infrastructure.
On this note, let’s take a look at the reasons pushing urban floods and the price we are paying for not reading the signs.
The memories of unprecedented floods in Mumbai, Srinagar and Chennai are still fresh. Ignored as sporadic or once-in-a-while event, urban floods have become regular, and increasingly devastating. The floods repeatedly draw our attention to only one fact: our urban sprawls have not paid adequate attention to the natural water bodies that exist in them. A case in point is Chennai, where each of its lakes has a natural flood discharge channel which drains the spill over. But we have built over many of these water bodies, blocking the smooth flow of water. We have forgotten the art of drainage. We only see land for buildings, not for water. And the result is in front our eyes.
An urban water body provides some crucial services such as groundwater recharge and flood management. If you ask the obvious question of how construction was permitted on the wetland, you will get a not-so-obvious response: wetlands are rarely recorded under municipal land laws, so nobody knows about them. Planners see only land, not water, and builders take over.
A number of cities including Chennai are both water-scarce as well as prone to flooding. Both problems are related—excessive construction which leads to poor recharge of groundwater aquifers and blocking of natural drainage systems. The city witnessed severe floods in 2015 when the entire city got completely submerged under water after it rained for a few days.
Delhi-based non-profit Centre for Science and Environment’s research shows that Chennai had more than 600 water bodies in the 1980s, but a master plan published in 2008 said that only a fraction of the lakes could be found in a healthy condition. According to records of the state’s Water Resources Department, the area of 19 major lakes had shrunk from a total of 1,130 hectares (ha) in the 1980s to around 645 ha in the early 2000s, reducing their storage capacity. The drains that carry surplus water from tanks to other wetlands have also been encroached upon.
The analysis also shows that the stormwater drains constructed to drain flood waters are clogged and require immediate desiltation. Chennai has only 855 km of stormwater drains against 2,847 km of urban roads. Thus, even a marginally heavy rainfall causes havoc in the city. Explaining the problem of pollution, the City Development Plan says: “The waterways of Chennai… receive flood discharge only during the monsoon season; the rest of the year these act as carriers of wastewater from sewage treatment plants and others.”
So Chennai needs to do what all cities must—undertake a detailed survey of the wetlands and then bring every water body and its catchment under legal protection. The Wetlands Conservation and Management Rules issued by the Union Ministry of Environment and Forests and Climate Change are toothless and meaningless. What is needed is to ensure that city development rules include a comprehensive list of water bodies and their catchment. Any change of this land use should not be permitted. Even this will not be enough unless the city values the water this land gives.
The Central government should provide funds for water supply to only those cities that have brought their own water sources under protection. The cities must show they have optimised local water potential before claiming access to water from far away sources. This will reduce the cost of supply. The city can invest the saved money in treating sewage, which pollutes the lakes and ponds in the first place. It is this vicious cycle that needs to be broken.
It is time we realised that a water body is not an ornamental luxury or a wasted land. A city’s lake is its lifeline.
Lakes and wetlands are an important part of urban ecosystem. They perform significant environmental, social and economic functions, ranging from being a source of drinking water, recharging groundwater to acting as sponges, supporting biodiversity and providing livelihoods. Their role becomes even more critical in today’s context when cities are facing the challenge of rapid unplanned urbanisation.
Their numbers are declining rapidly. For example, in the 1960s Bangalore had 262 lakes, now only 10 hold water. Similarly, in 2001, 137 lakes were listed in Ahmedabad city, and construction work had started on 65 of them. Another example exhibiting this increasing loss of urban water bodies is Hyderabad. In the last 12 years, Hyderabad has lost 3,245 ha of its wetlands.
The National Disaster Management Guidelines: Management of Urban Flooding report, published by the National Disaster Management Authority (ndma) in 2010, says that concretisation is a major problem in many cities and towns. According to the Union Ministry of Urban Development (MoUD), 31 per cent of the country was urbanised in 2011. The ministry says almost 50 per cent of the country will be urbanised by 2050. MoUD data also suggests a 54 per cent increase in the number of cities and towns between 2001 and 2011.
Natural streams and watercourses, formed over thousands of years due to the forces of flowing water in the respective watersheds, have been altered because of urbanisaiton. “As a result of this, the flow of water has increased in proportion to the urbanisation of the watersheds. Ideally, the natural drains should have been widened to accommodate the higher flows of stormwater. But on the contrary, there have been large scale encroachments on the natural drains and the river flood plains. Consequently, the capacity of natural drains has decreased, resulting in flooding,” says the ndma report.
Threats to urban water bodies
For the last two decades, urban water bodies have been a victim of unplanned urbanisation in India, because of which they face several threats such as encroachment, disposal of sewage, groundwater decline leading to fall in the level of lake, unplanned tourism and absence of administrative framework. Let us discuss these in detail:
Pollution: There has been an explosive increase in the urban population without corresponding expansion of civic facilities such as adequate infrastructure for the disposal of waste. Hence, as more people are migrating to cities, the urban civic services are becoming less adequate. As a result, almost all urban water bodies in India are suffering because of pollution. In many cases the water bodies have been turned into landfills. Guwahati’s Deepor beel, for example, is used by the municipal corporation to dump solid waste since 2006. Even the Pallikarni marshland in Chennai is used for solid waste dumping. Adding to the sorry state of urban water bodies is also the misuse of these water bodies by local communities for their cultural or religious festivals such the immersion of idols. Heavy metal concentration is found in Nagpur lakes, Bhopal lakes and Hussainsagar Lake in Hyderabad after the immersion of idols every year.
Encroachment: This is another major threat to urban water bodies. As more people are migrating to cities, the availability of land is getting scarce. Today, even a small piece of land in urban areas has high economic value. Hence, these urban water bodies are no more acknowledged for their ecosystem services but as real estate. Charkop Lake in Maharashtra, Ousteri Lake in Puducherry, Deepor beel in Guwahati are well known examples of encroachment. Another interesting example of encroachment and pollution, not by some private builder but the government itself is Pallikarni marshland in Chennai. The size of this city wetland is decreasing rapidly. Once a bird sanctuary, it is now the dumping yard of the city. The dumping of solid waste, sewage discharge, and construction of new buildings such as a railway stations and a new road have shrunk this wetland to a great extend. Another example of government encroachment is Sola beel in Guwahati where the state revenue department allotted the lake bed for construction, in spite of Gauhati High Court’s order to protect all wetlands in the state.
Illegal mining activities: Illegal mining for building material such as sand and quartzite both on the catchment and on the bed of the lake have extremely damaging impact on the water body. For example, the Jaisamand Lake in Jodhpur, once the only source of drinking water for the city, has been suffering from illegal mining in the catchment area for the last 20 years, despite a court order to stop mining in 1999. Badkhal Lake in Faridabad has dried up in the same way. Unmindful sand mining from the catchment of Vembanad Lake on the outskirts of Kochi has lowered the water level in the lake.
Unplanned tourism activities: Using water bodies to attract tourists has become a threat to several urban lakes in India. Tso Morari and Pongsho lakes in Ladakh have become polluted because of unplanned and unregulated tourism. Another example is Ashtamudi Lake in Kaerala's Kollam city that has become polluted because of spillage of oil from motor boats.
Absence of administrative framework: The biggest challenge remains the government apathy towards water bodies. This can be understood from the fact that the government does not even have data on the total number of urban water bodies in the country. Few cities have recorded water bodies because of court rulings. A 2010-11 Comptroller and Auditor General of India report on the plight of 22 lakes in 14 states said: “MoEF&CC (Union Ministry of Environment & Climate Change) had not identified wetlands associated with each river/lake and no identifications of risks to these wetlands due to pollution of river water/lake water had been carried out by CPCB (Central Pollution ControlBoard). Further, CPCB had not identified the major aquatic species, birds, plants and animals facing risks due to pollution of rivers and lakes.”
From ignoring warnings to delays in taking actions, Tamil Nadu administration played its part in making the December floods more devastating
On December 1, houses on the ground floor in Jafferkhanpet, a neighbourhood in southern Chennai, started to inundate because of torrential rains. By five in the morning, almost 80 per cent of the city was under four metres of water. The situation continued for the next 72 hours, killing more than 500 and destroyed infrastructure worth Rs 500 crore. It was most intense of the three spells that had battered the city in just one month. Earlier, the city had received incessant rains from November 11 to 13, and then from November 15 to 17.
Chennai received 1,200 mm of rainfall in November 2015, which was the highest rainfall the city received in November in the past 100 years. The city on an average receives 407.4 mm rainfall in November. On December 1, Chennai received 300 mm rainfall, making it the wettest December day ever recorded in the city. The normal rainfall for Chennai in December is 191 mm.
A closer look suggests that the intensity and the resultant losses due to the recent floods could have been greatly reduced. Tamil Nadu faltered on several accounts. Firstly, it failed to act despite a clear warning from the India Meteorological Department (IMD) of heavy rains. Secondly, the state administration has over the years done little to prepare for disasters despite being flood-prone. Thirdly, Chennai and its neighbouring areas have witnessed unplanned urbanisation in recent years that has destroyed the city’s natural flood sinks such as marshlands and river channels.
IMD in mid-October issued a forecast that predicted 11-12 per cent above normal rains in the southern states with a probability of about 90 per cent. It had said that the northeast (winter) monsoon, caused by retreating monsoon winds that attain moisture from the Bay of Bengal on their way back south from the northeastern direction, would be stronger. These winds are responsible for the rains in the southern states of Andhra Pradesh, Tamil Nadu, Kerala and parts of Karnataka between October and December. The IMD forecast though did little to prepare the states for the situation.
On December 1, an ill-prepared Tamil Nadu administration decided to open the gates of the Chembarambakkam reservoir, and the released water inundated the city. A public interest petition filed in the Madras High Court against the Tamil Nadu government suggests 1,104 cubic metres per second of water were released into the Adyar river, which meets the water requirements of the city. Highlighting how the decision was delayed, the petition, filed by Chennai-based businessperson Rajiv Rai, says that the water was released after a warning was issued at midnight. “If one studies the levels of water in the various catchment tanks on a daily basis, one can see that the reservoirs had much greater inflow than outflow right through November 2015,” says the petition. It alleges that state chief secretary K Gnanadesikan waited for three days after the Public Works Department (PWD) wrote to him on November 29 to release water from the reservoir. “The chief secretary, even though he was well aware of the reports that there was going to be heavy downpour for a few more days, didn’t direct the release of water when he received the warning from PWD,” the petition says.
Clueless, yet confident
The administration was caught unawares despite the fact that floods are not new to the state. According to a 2013 Comptroller Auditor General of India (CAG) report, there have been 50 cyclonic storms in the region between 1900 and 2009. Even the hazard profiles of coastal districts prepared in the aftermath of the 2004 tsunami that hit the Tamil Nadu coast shows that most of the coastal districts experience flooding during the retreating monsoon, which normally accounts for 48 per cent of the rainfall in the state. “Heavy rains during the months of October, November and December inundate low-lying areas, coastal areas and the areas nearby major irrigation sources,” states the disaster profile prepared by the district administration.
The level of unpreparedness of the city administration can be gauged from the fact that the Chennai Metropolitan Development Authority (CMDA), the key urban planning agency for the city, still relies on an outdated hazard profiles of Tamil Nadu, which says none of the areas in the state are flood-prone. According to CMDA’s hazard profile document, “From the flood hazard map of India (mapped by IMD, New Delhi), it is seen that no area in Tamil Nadu falls in the risk zone.” The document says that few areas in Chennai might get flooded due to heavy storms and for this, flood affected areas have to be mapped. According to N Madhavan, who has worked with the Municipal Corporation of Chennai, ward-level vulnerability mapping was done after the 2004 tsunami. “These efforts went waste as boundaries of wards and zones changed following the expansion of the city,” says he.
The callousness of the state administration does not end here. The State Disaster Management Authority, which was set up in 2008 under the Disaster Management Act, 2005, has not even met once, according to the 2013 CAG report. Close to seven years later, the state is yet to come up with disaster management rules. It was only in May 2015, following the Nepal earthquakes, the Municipal Corporation of Chennai started preparing a comprehensive disaster management plan which predefines the roles of officials during a disaster.
Only to get worse
The northeast monsoon is generally known to bring a few heavy showers amidst scanty rains to the southern states. Between October and the first week of December, 27 of the 34 districts in Tamil Nadu and Puducherry had received 10 per cent excess rainfall with several districts registering more than double the normal rainfall. While normally it rains heavily for three to four days and is followed by long dry spells, this year it rained continuously with practically no respite for more than a month. Chennai received 1608.6 mm rainfall between October 1 and December 16, 2015, which was more than twice the amount of rainfall the city received during the last three months of 2014 (719.7 mm).
“There are several factors responsible for the performance of the northeast monsoon in southern states. The El Niño Southern Oscillation (ENSO) along with the Indian Ocean Dipole and the Madden-Julian Oscillation (MJO), which are heating patterns in the Indian and Pacific oceans, has caused a lot of atmospheric activity. These have culminated in the rain in the southern states,” says B P Yadav, IMD director (see ‘Winds of change’).
Several studies since early 2000s have pointed to a positive correlation between ENSO and the northeastern monsoon. “ENSO has been known to suppress southwest monsoons while enhancing the northeast monsoons. This year we have seen this to a great extent,” says Gibies George, a senior research fellow at the Indian Institute of Tropical Meteorology (IITM), Pune.
The other global pattern that has influenced the northeast monsoon in India this year is the MJO—a traversing global oceanic and atmospheric phenomenon that has been found to have global climatic ramifications. MJO has a 30-60 day cycle that is characterised by eastward moving clouds in the tropics over the Indian and Pacific Oceans. It has been seen that when the MJO cycle is close to 30 days, it aids rainfall in the country while a cycle longer than 40 days causes suppression. “A strong MJO remained practically stationary over the Indian Ocean all through November and this has been a major factor in the heavy rainfall. The differential due to MJO has forced rain-bearing winds into the southern region of the sub-continent. The influence of MJO has been in line with previous observations,” says D S Pai, director, Long Range Forecast division, IMD.
These connections are not the only newly emerging patterns regarding the northeastern monsoon. A close look at the seasonal rainfall levels in recent decades across districts in coastal Andhra Pradesh, Karnataka and Tamil Nadu reveals that the northeast monsoon has become progressively more bountiful. A 2012 study in Theoretical and Applied Climatology makes use of homogenous rain gauge data maintained by IITM to show that winter rains in peninsular India have exhibited a positive rainfall trend of 0.4 mm per day per decade between 1979 and 2010. At the same time, an increase in the number of extreme rainfall days and a decrease of normal rain days have also been observed in several parts of south India. According to George, this trend is similar to what has been observed during the summer monsoon. “We have observed that with the warming of the atmosphere, the moisture carrying capacity of the air also increases. Hence, with warming we can expect to see an increase in the magnitude of rain events and the frequency of extreme rain events. Normal rain days will become fewer and less frequent,” says George. Experts warn that rainfall during northeast monsoon is likely to increase in the future, another reason the state administration should get its act together.
Concrete proof of a disaster
A 2014 analysis by the Indian Institute of Science, Bengaluru, shows that the rate of urbanisation in Chennai has increased by 20 times in the past four decades—and this came at the cost of its green spaces. Experts say that unplanned urbanisation increases the chances and intensity of flooding in two ways. Firstly, concrete jungles obstruct and encroach upon the natural flow of waterbodies and create pockets that trap water, which increases the flood intensity. Secondly, the sewerage generated by the people gets mixed with the water and clogs the natural channels and storm water drains.
Chennai suffers from both the problems. The three rivers in the city—Cooum, Adyar and Kosathalaiyar—are highly encroached upon and that has reduced the amount of water runoff into the Bay of Bengal. The city has four sewerage treatment plants at four centres, but the treated water that flows through natural channels, often gets mixed with untreated wastewater from colonies and industries on the way.
Even the city’s numerous waterbodies and marshlands that should have acted as sponges are either encroached upon or over polluted. For example, in 2011, the Pallikarni marshland, the city’s biggest flood sink, was reduced to just 12 per cent of its size before Independence. The marshland, which was once spread over 5,000 ha, now houses government buildings and research institutes and a dumpyard that is gradually growing in size. The area of the Perungudi dump yard, located on the north-eastern part of the marsh, doubled—from 32 ha in 2002-03 to 75 ha in 2013, according to Tamil Nadu State Land Use Research Board. The areas affected by sewage and solid waste dumping doubled between 2003 and 2005, says a research by Care Earth, a Chennai-based research institute.
M Sakthivel of the department of geography, University of Madras, says that the groundwater in the marshland is highly polluted due to garbage dumping. Experts also say groundwater recharge, which is essential for flood mitigation, has reduced substantially because of urbanisation.
Sitting on a flood bomb
India is urbanising at an alarming rate, which is a cause for worry. According to the Union Ministry of Urban Development (MoUD), 31 per cent of the country was urbanised in 2011. The ministry says almost 50 per cent of the country will be urbanised by 2050. MoUD data also suggests a 54 per cent increase in the number of cities and towns between 2001 and 2011. And this rapid urbanisation has happened without proper planning, say hydrologists. “There is a complete disconnect between geological and hydrogeological cycle and urban planning,” says Saswat Bandyopadhyay, head, department of environmental planning, Centre for Environmental Planning and Technology University, Gujarat.
The problem of floods in urban areas became so acute that in 2010, the National Disaster Management Authority (NDMA) recognised urban floods as different from riverine floods. It said urban floods “happen in a relatively short period of time and can inundate an area with several feet of water”. It also said that urbnanisation creates artificial catchments which increase the flood intensity by six times as opposed to riverine floods. Consequently, flooding occurs quickly in urban areas. Delhi-based hydrogeologist Partha Sarathi Datta says, “Studying topography, drainage, rainfall and soil lithology of catchments plays an important role in urban planning, but sadly good detailed studies are not available.”
The effects of unplanned urbanisation are already visible (see ‘Losing base’). The mangrove cover in Mumbai reduced from 28 per cent to 18 per cent between 1925 and 1994. In the same period, the city’s built-up area increased from 12 to 52 per cent. Srinagar lost almost 50 per cent of its waterbodies between 1911 and 2004. This was the major reason for the 2014 floods in the city. Bengaluru, which had 262 lakes in the 1960s, has only 10 lakes that can be called healthy.
Apathy of government departments is the main reason for the degradation of urban wetlands and channels. The 2010 Wetland Rules, for example, do not have enough teeth to protect waterbodies. To protect a wetland under the rules, the state government needs to identify the waterbodies and then prepare a document. This document gets reviewed by the Central Wetlands Regulatory Authority and finally the comments are sent to the Union government, which then notifies a wetalnd to be protected. Hence if a state misses any polluted lake, it will be neglected—unless citizens approach the court. “Since urban lakes have unique ecosystem, there is a need for strong protection laws,” says Jasveen Jairath, convener of Save Our Urban Lakes, a citizens’ initiative for saving waterbodies in Hyderabad.
So what should be done? According to Delhi-based non-profit Centre for Science and Environment, urban planners should undertake a detailed mapping of waterbodies, natural drainage and flood-prone areas in cities using remote sensing. And then integrate the drainage system of the city including rivers, rivulets, ponds, lakes and other natural drainage systems. The non-profit also suggests policymakers to relook the development plans approved by city authorities and find out whether they violate the hydrological cycle of the city. Finally, it calls for stronger laws to protect urban lakes and the setting up of a single authority for the management and restoration of waterbodies.