Kolkata Municipal Corporation has built concrete structures around the lower portion of several tree trucks along Loudon Street, violating national urban green guidelines and going against its own action earlier where it demolished over 4,000 such structures across the city.
The concrete structures along Loudon Street in south-central Kolkata are a little less than 1ft in height from the footpath. There is soil surrounding the tree and then a layer of bricks as the outer boundary. The casting of the bricks makes the structure tough.
Naturalists blame such concrete structures around a tree trunk and the base of a tree as one of the factors for the toppling of trees. A green activist said that the Calcutta High Court had in 2019 barred any concrete structure around the base of a tree.
A KMC official denied that the civic body had built any new structures but had “only restored some old structures that had broken”. The official said they had started demolishing the structures surrounding the trees’ base.
When The Telegraph visited Loudon Street on Friday evening, there were still many such structures surrounding trees. They had small blue and white tiles on the outside.
“We will see if there are more such structures and demolish them,” the official said.
Concrete structures around the base of trees along Loudon Street on Friday evening. Picture by Bishwarup Dutta
Every year, tens of trees topple in the city during the monsoon. A toppled tree can destroy property, hurt people and also results in the loss of greenery. Naturalists blame too much concrete around a tree for the frequent toppling.
“I was a little surprised to see that the KMC has again built concrete structures surrounding the trees. This was more surprising because the KMC had themselves demolished thousands of such structures after the Calcutta High Court ordered the removal of such structures surrounding trees in 2019,” said Bonani Kakkar, a green activist.
Naturalist Arjan Basu Roy explained why this casting surrounding the tree trunk harms the tree. “The trunk is supposed to develop as a trunk, which means it should receive adequate sunlight and air. If the trunk does not get air and light, that portion of the trunk will slowly rot. This will make the tree vulnerable to toppling,” said Basu Roy.
He added that when there is some pull or thrust on the tree, it might break from the area of the trunk that has rotted after not receiving light and air for years.
Across Kolkata, there are many such structures around the tree base. Despite the KMC demolishing some of these structures, there are thousands still left.
Kakkar had written to senior state government officials. She said she was glad that the KMC has started demolishing structures.
“But the civic body has to be more responsible and sensitive in preserving the city’s greenery,” she said.
Another factor that is widely blamed for the toppling of trees is concretizing the entire surface surrounding a tree. It does not allow the root system to grow horizontally and makes the tree unstable and prone to toppling.
The national urban green guidelines, 2014 mentioned that a minimum of 1.25m X 1.25m space should be left uncemented surrounding a tree, but that is rarely done in Kolkata.