Work begins on mangrove wall in Mumbai
The construction work began two years after the state first made the proposal.Updated: May 25, 2019, 23:56 IST
Two years after the state’s proposal to build walls to protect Mumbai’s mangroves, construction has begun on the project as per the Bombay high court’s (HC) orders. Debris dumping, which destroys mangrove ecosystems, has been a recurrent problem and while opinion is divided on whether the proposed walls will provide the necessary protection, the state is spending approximately ₹13 crore on the project.
On September 17, 2018, the HC bench of justices Abhay Oka and Riyaz Chagla said a compound wall of 50 metres should be constructed on the landward side of mangrove areas and CCTV cameras should be installed at vulnerable areas. After delays in procuring permissions, construction began earlier this week, after the model code of conduct was lifted. The walls will be constructed in different locations across the city, between the buffer zone and where the reserved forest begins. Security guards will also be appointed by the mangrove cell and barbed wire will be put on top of the walls.
Construction of a 2.5 metre-high wall along 550m at Kanjur has been going on for 10 days. “It is protecting the reserved mangrove forest close to the Kanjurmarg dumping ground. The project will be replicated across 650m in Mandale and Mankhurd soon,” said MS Bothe, range forest officer (east), Mumbai Mangrove Conservation Unit (MMCU).
In addition to mangrove sites in Mandale, Mankhurd and Kanjur in the eastern suburbs, five areas – two in Malad-Malwani, one in Madh and two in Charkop – are also getting walls. “All these areas had fallen prey to mangrove destruction through debris dumping and encroachments. Through demolition drives, encroachments were removed over the past year and high tide water channels were dug up,” said N Vasudevan, additional principal chief conservator of forest, state mangrove cell. “Installation of CCTV cameras is underway, and drones will be used to monitor these patches, subject to permissions,” said Prashant Deshmukh, range forest officer (west), MMCU. HT was the first to report in April 2017 that the government was planning to build walls to protect Mumbai’s mangroves. The cost of constructing the wall is ₹16,000 per metre, and approximately ₹8 crore has been spent on the first phase. The second phase of the project will cost approximately ₹5 crore and include extending the wall, which will not be continuous, by another 54km, along other mangrove forests in the city.
Environmentalists were sceptical of the utility of the walls. “This act of building walls is bad precedent as it will actually encourage private land owners to construct their own walls on private land and kill mangroves causing more destruction,” said Stalin D, director, Vanashakti and member of the state mangrove committee.
Scientific opinion is divided upon whether the walls will affect tidal water flow. “The minute we introduce concrete within any wetland or mudflat space, it is going to restrict the flow of tidal water even if culverts or space is provided for it,” said Arvind Utawale, executive secretary, Mangrove Society of India. “Nature will destroy that wall. The movement of soil and intertidal forces, and the sheer weight of the wall on that region will force it to sink down regular intervals of high tide water ingress. We witnessed a similar project on a beach in Goa, and it did not survive. The same is expected here as well,” he said.
However, scientist G Kantharajan, who was carried out several studies on mangroves along the west coast, had a contrary view. “The possibility of mangroves growing towards the landward side is very little while the probability of construction eating into mangroves moving towards the seaward side is high,” he said.