Tamil Nadu coast has 69 erosional zones, 20 sites in need of reformation

A shoreline analysis conducted by the National Centre for Coastal Research (NCCR) has identified 69 erosional stretches along the Tamil Nadu coast, and flagged 20 sites that require reformation.

Reformation is needed in several areas owing to the presence of partially damaged seawalls. In Chennai, the stretch from Tiruvottiyur to Kasimedu Harbour requires attention. Chengalpattu needs reformation at Olive Beach, Devaneri, and Mamallapuram. In Mayiladuthurai, stretches at Tharangampadi and Pombuhar are affected. In Nagapattinam, reformation is needed at Akkaraipettai and Velankanni. Ramanathapuram requires action at Mookaiyur, and in Thoothukudi, Vembar, Tiruchendur, and Manappad are stretches needing attention. Kanniyakumari has several affected areas, including Mel Midalam, Enayamputhen-thurai, Erayumanthurai, Edappadu, Vallavilai, and Marthandamthurai. In Puducherry, Kottakuppam to Kurichikuppam and Pondy Marina need reformation.

The analysis was done as part of the Shoreline Management Plan (SMP), mandated by the Coastal Regulation Zone (CRZ) Notification, 2011. The notification requires States to create a Coastal Zone Management Plan that includes the classification of CRZ categories, an assessment of shoreline changes, the SMP, and a coastal land use map that highlights fish breeding grounds, turtle nesting sites, and areas used by coastal communities, among others.

The SMP, prepared by the NCCR, involved a month-long survey of the coast by multiple teams on foot. Several factors were considered for a comprehensive shoreline assessment, including the coastal geomorphology, the presence of river inlets, eco-sensitive areas, and the socio-economic conditions of coastal populations. Additionally, the analysis incorporated data on coastal structures, met-ocean parameters such as wind, tide, wave conditions, and sediment budgeting. The SMP includes an action plan designed to address immediate and long-term needs for coastal protection. An overview of the SMP was presented at a capacity building workshop organised by the Department of Environment for officials from Chennai, Chengalpattu, and Tiruvallur. The NCCR’s SMP outlines strategies to address coastal erosion, while also considering the sustainable development of the coastline.

Nearly 13.5% of Tamil Nadu’s coastline is occupied by artificial structures. These, besides river regulation and sea-level rise, contribute to coastal erosion and accretion. Moreover, Kanniyakumari and Tiruvallur stand out for having the highest concentration of coastal structures. While the former mostly has coastal protection structures, the latter is home to more coastal infrastructure developments. These distinctions are important in tailoring effective strategies for each region.

Rahul Nadh, Member Secretary, Tamil Nadu State Coastal Zone Management Authority, said the SMP was pending approval from the Government of India and was expected to be published for public comments, along with the Coastal Zone Management Plan and the coastal land use maps, in January 2025.