Chennai floods again after losing many blue and green spaces [Interview]

Heavy rains have again flooded the south Indian city of Chennai, bringing back memories of and comparison to the December 2015 floods.
Even though the present situation is not as bad as the December 2015 floods, if heavy rains return in bouts in the next few weeks the situation could worsen, said Jayshree Vencatesan, managing trustee of the Care Earth Trust.
The suburbs of the city have consistently lost their wetlands and green spaces to construction activity, and this has made the city very vulnerable to flooding.
The 2015 floods increased people’s awareness of water logging and flooding, and they are more eager to restore wetlands and green patches. Only an effective engagement between multiple stakeholders can help deal with situations such as this.

There are heavy rains in the south Indian city of Chennai and the metropolis has flooded, bringing back memories of the of December 2015 floods. Mongabay-India talked with Jayshree Vencatesan, managing trustee of the Care Earth Trust (CET), an NGO which has been working for decades to conserve and rehabilitate the city’s wetlands and forest patches. The work by the CET was instrumental in the Tamil Nadu Government declaring the Pallikarnai marsh as a protected area in 2007.

Vencatesan said that even though most parts of the city are either water logged or flooded, the present situation is not like the 2015 Chennai floods situation.

However, if there are further rains in Chennai in the coming weeks then the situation could get worse with the storage tanks, waterways, wetlands and the underground aquifers being already full. This was the pattern in 2015, when the heavy rains started on November 8, and by December 1 the city had received five bouts of rains, leading to heavy floods.

The CET has been studying the cyclical nature of Chennai floods and droughts, and the trend shows heavy flooding once in 10 years. However, with the 2021 floods, this periodicity has reduced to six years. The pattern of of a few extreme rainfall days during the rainy bout has consistently continued since 2002.

Even though a linkage with climate change seems likely, there is not enough ground data to make the corroboration, she said. “Chennai manages its water poorly, thereby intensifying the impact.”

Over the years, the trend of losing wetlands and forested areas to built-up space continues. Vencatesan explained that the maximum land use change is happening in the suburbs where construction activity is riding over the blue and green spaces. Unlike the lakes and reservoirs, the wetlands are not even enumerated and they are the ones facing either total loss or land fragmentation. Similarly, in the green areas, the reserve forests have remained stable in their area, but the orchards and paddy fields have disappeared.

The city is losing its wet character; losing its character to handle water. From a policy perspective, Chennai is always planned itself as a dry city whereas in reality with an average annual precipitation of 1428 mm, it is not a dry city. The other factor that is also missed out in the planning process is that Chennai is a coastal city.

Engagement with multiple stakeholders is absolutely critical to strengthen Chennai’s preparedness to deal with such situation, she emphasised. The 2015 Chennai floods created widespread understanding and awareness of flooding and water logging. However, on the flip side, the city dwellers have now become paranoid about flooding. For people who used to welcome rains in Chennai, now there are fears with a slight excess in rainfall.

More people involve themselves with the restoration of water bodies and greening activities. There are volunteer groups, resident welfare associations are joining and there is increased support from the government. In 2021, the state government has been working and providing information proactively to the people, which is a welcome change from 2015, she said.

With the 2021 floods, the CET is working to prepare crowd-sourced flooding maps. These maps will give data on which are the new areas getting flooded and which areas have remained relatively flood-proofed. The next step would be to study why this is so.