Not only rains, Mumbai should be blamed for its floods

Published: Thu, 09/21/2017 - 09:25 Updated: Thu, 09/21/2017 - 09:26

Mumbai masterminds its floods with its uncontrolled craving for development—by converting floodplains, bottlenecking rivers and reclaiming several hectares of coastal areas

Dhwani Shah Mumbai

The torrential rain that battered Mumbai on September 19 almost made the denizens of the metropolis gasp in horror as they waited to see if the downpour would again inundate the city as it did just a few days ago on August 29. The deluge that hit the city last month was a chilling reminder of the floods that brought the megacity to a standstill on July 26, 2005, and led to the death of over 500 people and 16,307 cattle, affected 30,000 vehicles and damaged more than 2,000 houses. A lack of warning by weathermen before the August 29 downpour had caught the city off-guard and led to a complete breakdown of suburban train services of Central and Harbour railways of Mumbai Division.

This time, however, the city had received warning of heavy to very heavy rainfall from the Met department. A total of 108 flights were cancelled and the suburban railway services were hit, with trains running late. Several cars were abandoned on the roads and heavy traffic was witnessed even after the rain reduced. For hours after the rain had stopped, the water did not recede in several parts of Mumbai. Thousands of people were stranded at the railway station, in trains, and on roads. Some decided to stay put at their offices or homes of relatives and friends.

For Mumbai, heavy rain is not the only cause of floods. The metropolis masterminds its floods with its uncontrolled craving for development. This has led to the conversion of floodplains, bottlenecking of rivers and reclamation of several hectares of coastal areas. Shrinking open spaces, cutting of trees, increasing concretization of land open to the sky has led to lesser ground area for the water to seep in. This has contributed towards the increase in rainwater runoff and has increased the pressure on the city’s stormwater drainage systems built in the colonial era.

Mumbai’s rivers and creeks provide it with a natural drainage pattern for draining excess rainwater. The rivers of Mumbai have witnessed the brunt of the development. The rivers at several locations along the course have been diverted, reclaimed and concretized with walls. Several areas of mangroves and mudflats, classified as CRZ IA areas that act as protection zone between the sea and land, have been reclaimed by builders and government. Floodplains have been encroached by slums and concretized. Moreover, some buildings have been built abutting or altering the river and no action has been taken so far.

The mangroves and creeks of Mumbai also face a threat from the 6,000 MT or more waste generated every day. This waste is dumped unsegregated and untreated in the dumping grounds which are created over areas of mangroves and open spaces. The dumping grounds in Kanjurmarg, Mulund, Shivaji Nagar, and Gorai were developed on mangroves and mudflats. The waste that is dumped unattended, forming high mountains, have played a significant role in bottlenecking the rivers. Plastic has created havoc in Mumbai’s drainage system. Till date, there is no solid waste management system functional on the ground.

The Bandra-Kurla Complex, MHADA layout of Charkop and several other areas have been developed by filling the creek areas that harbour mangroves and mudflats. With constant clearance of the forest areas of Sanjay Gandhi National Park and Aarey Milk Colony, the ground’s capacity for water retention has been reduced and therefore, soil erosion and floods are likely to increase. Many proposals have been submitted to the forest department seeking permission for the clearance and conversion of the forest areas in and around Mumbai. If such conversions continue, Mumbai’s protection shield will diminish.

Apart from the recent floods, Mumbai has many lessons to be learned from the Chennai floods of 2015 and the floods of 2005. Urgent steps towards sustainable development of the city should be taken. Efforts should be taken to revive the rivers that have been choked. Mumbai is a coastal city, several areas of the city are below the mean sea level. No region of Mumbai is more than 200 to 300 metres away from the sea. In view of climate change and rising sea levels, only a sustainable approach can lead to better infrastructure and quality of life.