MCZMA nod for 22-km wall to protect mangroves

Among the coastal protection projects that the Maharashtra Coastal Zone Management Authority (MCZMA) recently sanctioned for the Mumbai Metropolitan Region (MMR)

Among the coastal protection projects that the Maharashtra Coastal Zone Management Authority (MCZMA) recently sanctioned for the Mumbai Metropolitan Region (MMR) are proposals to build bunds to protect the coastline and walls around mangrove forests.

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Both plans got the coastal regulation zone (CRZ) clearance on February 2 and the minutes of the MCZMA meeting were published on Wednesday. These projects fall under CRZ 1A, which has the highest protection criteria under coastal protection laws.

“The projects are crucial for coastal protection of MMR, which is threatened by sea level rise as per national and international studies. While the mangrove wall will protect the salt tolerant trees as per the Bombay high court’s (HC) directions, the seawall will be the first barrier against rising seas,” said a senior MCZMA official. The final nod for both projects will be issued by State Environment Impact Assessment Authority (SEIAA).

Retaining concrete walls will be constructed between the buffer zone and reserved mangrove forests at 27 locations in central Mumbai, 14 locations in western suburbs, and eight locations in Navi Mumbai and Thane creek flamingo sanctuary. These include Colaba, Turbhe, Wadala, Mankhurd, Sewri, Vashi, Mulund, Kandivli, Borivli and Versova. The walls will cover 22.1km of mangrove forest and the total cost of the project is ₹13 crore. Work is already underway at Mandale, Mandkurd, Malad, Madh, and Charkop.

The public works department’s (PWD) proposal to build anti-sea erosion bunds, or seawalls, along with tetrapods at Manori, Danapani, Walkeshwar, Rangaon and Bhuigaon was also approved. All five areas face high erosion and high tide inundation problems.

Urban planners and experts questioned the efficacy of these concrete structures. “Walls protecting mangroves can actually become a security issue, lead to increase of encroachments, dumping of garbage etc. Alternatives in the form of just chain-link fences or bio-fences are much more sustainable solution,” said Pankaj Joshi, director, Urban Design Research Institute. He added that the state should consider technologies that are environmentally sustainable to protect coastal zones.

“Bringing in concrete in the form of walls, tetrapods or bunds will ultimately increase tidal water accumulation issues and lead to high flooding during monsoon. These plans, even for urban zones, will be disastrous for any natural environment,” said marine biologist E Vivekandan.