Monthly Archives: October 2016

IT and housing boom choke Chennai’s last marshland

Only a tenth of the original area of Pallikarani marsh is now left after Chennai's industry and housing boom

Only a tenth of the original area of Pallikarani marsh is now left after Chennai’s industry and housing boom


By L Ajith

CHENNAI: As construction and industry boom destroy a rare marshland that feeds groundwater sources and drains floodwaters in this sprawling south Indian commercial hub, conservationists are trying to save a tenth of its original area that is still left.

Located about 20 km south of Chennai city centre, Pallikkaranai marsh is the metro’s last remaining natural wetland, one of the rare ecosystems that India’s National Wetland Conservation and Management Programme (NWCMP) is trying to save.

After reclamation for housing, infotech industries and roads, the marshland has now shrunk to 6.9 square km from its 60 square km recorded in the 1960s.

As a result, now it is impossible to stream and drain flood waters into the marsh during heavy monsoon rains. Buildings, tarmacs and concrete spaces have not only replaced what once used to be wetland, but also flank its edges, preventing natural drainage. So the excess storm water inundates these spaces without seeping into the ground or draining into the wetland and then to the Bay of Bengal that lies adjacent to it. At the same time, without recharge of groundwater aquifers, Chennai and suburbs face severe drinking water shortage.

During the 2015 monsoon season, parts of Chennai were flooded and remained inundated for upto a month after and extreme rainfall events. Experts blamed the disaster on rampant, illegal and poorly designed construction.

Pallikkaranai marsh absorbs its share of water, but it is choked now. Due to dumping of waste and sewage, Pallikkaranai marsh is undergoing a character change besides shrinking to a tenth of its original size, as Dr. Jayashree Vencatesan of the Care Earth Trust explains. To prevent such ecosystem losses, conservation of forests, inland wetlands, and coastal and marine ecosystems need to be integrated into policy and planning, recommend Ritesh Sharma and Shantanu of Economics of Ecosystems and Biodiversity- India Initiative.

“The consequences of loss of Ecosystem and Biodiversity causes natural disasters like floods and droughts and shortage of crops, fish, and vegetables,” says Ravindra Singh of the German international development agency GIZ.

Wetlands not only prevents floods, but also protect the shoreline, and suck up and store carbon dioxide, thereby reducing greenhouse effect that leads to global warming. Pallikaranai marsh is special, as it hosts several rare, endangered or threatened species. It is home to over 100 species of fish and 136 species of birds, including migratory birds, as Singh notes.

A recent workshop of the Indo-German Biodiversity Programme in Chennai, Ashok Lavasa, IAS, Secretary in the Ministry of Environment, Forest and Climate Change that sponsored the event said economic growth and conservation of natural capital should go hand in hand. Both are essential to protect ecosystem services that support human well-being and prosperity.

“India is one of the 17 mega-diverse countries in the world…With only 2.4% of the world’s geographical area, her 1.2 billion people co-exist with over 47,000 species of plants and 91,000 species of animals. Several among them are keystone and charismatic species,” as Lavasa points out. At the same time, the country supports one sixth of the world’s livestock population. In such a context, balancing the needs for now and for future is often a balancing act indeed.

Still, considering the seriousness of ecosystem losses and the hazard exposure, especially with uncertain and changing weather patterns, conservation needs to gain an upper hand in many cases. As Prof Saudamini Das of the Institute of Economic Growth, New Delhi, points out, coastal cities such as Kochi in Kerala or Kolkata and Mumbai that are built on reclaimed water bodies and mangroves are also possibly exposed to a future flash floods. These lessons and warnings should serve as wake up calls.