City coastal maps to be upgraded for better view of structures, landforms

The adjustment in scale could have implications for real estate, public infrastructure and conservation. Environmentalists have previously used such coastal maps to point out the destruction of mangroves, wetlands and mudflats in and around Mumbai

Mumbai: The Maharashtra government has engaged the National Centre for Sustainable Coastal Management (NCSCM), Chennai, to upgrade coastal zone management plans (CZMP) for Mumbai and other coastal districts. The plans will be redrawn at a scale of 1:4,000 to replace existing maps (which are at a scale of 1:25,000). It will give citizens and planners a granular view of structures and landforms in Coastal Regulation Zone (CRZ) areas.

Mumbai, India - May 27, 2019:- Aksa Beach after BMC organised clean up at Aksa, Madh Island, Mumbai, India, on May 27 2019. (Photo by Aalok Soni/ Hindustan Times) (Aalok Soni/HT PHOTO)

This has been a demand of environmentalists for several years, after 1:4,000 coastal maps were mandated under amendments to the CRZ Notification in 2011. Experts said the move is welcome. The adjustment in scale could have implications for real estate, public infrastructure and conservation. Environmentalists have previously used such coastal maps to point out the destruction of mangroves, wetlands and mudflats in and around Mumbai.

Alan Abraham, a city-based architect, said, “It’s like seeing through a magnifying glass. The greater the scale, the more detail you get and the better decisions you can take. At a scale of 1:25,000, you can’t really make out much of what’s on the ground, and upgrading the maps is a good step towards transparency. But 1:4,000 is still a very primitive scale. It might show you a large patch of mangroves in Vikhroli, but it might miss a small patch in Versova. A scale of around 1:500 would be better and is possible with available technology.”

“Redoing the maps at 1:4,000 will mean a redrawing of the HTL, which should be done keeping in mind sea-level rise. If maps from 1991, when the CRZ came into force, are used as the base year, it will reveal the extent of CRZ violations. Unfortunately, many of these have been perpetrated by government agencies,” said Debi Goenka, executive trustee, Conservation Action Trust (CAT).

The Maharashtra Coastal Zone Management Authority (MCZMA) had last month recommended that the NCSCM relook at the city’s HTL based on an amendment in the CRZ rules dated November 26, 2021. But adjusting for scale won’t fix other issues with Mumbai’s coastal maps, which were published by the MCZMA in February 2022 and serve as the key planning document to preserve the coast.

For example, they combine all CRZ-IA (ecologically sensitive areas such as mangroves, beaches, creeks and mudflats) areas into a single head. It makes no differentiation between these landscapes, which could affect regional planning. Similarly, CRZ-IB categories are also combined, with no distinction between beaches, rocky outcrops and intertidal zones.

“There were several changes made to the CZMP between the draft and final stage, without any explanation. These should be fixed by the NCSCM now. The Maharashtra Remote Sensing Application Centre in 1994 had published rigorous maps of the state’s coastline which can be used as reference, but have so far served no planning purpose,” said Goenka.