The Puducherry Government has requested the National Centre for Coastal Research (NCCR) under the Ministry of Earth Sciences, to prepare a comprehensive Shoreline Management Plan (SMP) to protect the erosion-ravaged Pillaichavadi and Kalapet coasts in the north of Puducherry, through eco-friendly solutions.
Highly-placed sources in NCCR said the agency would be undertaking a detailed study of the Puducherry coast including the shoreline changes, coastal processes, and existing protection measures.
Since Puducherry shares an intermittent border with neighbouring Tamil Nadu, NCCR will study the entire coastline till Marakkanam in the north, Cuddalore in the south, and the stretch from Karaikal to Nagapattinam in the north.
According to M.V. Ramana Murthy, Director of NCCR, “The study has been initiated to evolve strategies for the protection of Puducherry’s coast. The study aims at understanding various dynamical aspects of the coast and coastal morphological data including sea level rise, currents and circulation, tides, waves, bathymetric variations, sediment transport, and shoreline changes to develop models on shoreline changes in priority areas and to arrive at remedial measures to protect the coastline from natural and human perturbations.”
A report by NCCR said around 57% of Puducherry’s coast was eroding. Puducherry is second only to West Bengal, which recorded erosion at 63.5% followed by Kerala at 45% and Tamil Nadu at 41%. The report shows that a long-term cumulative analysis of the coast from 1990 to 2016, indicates that 57% of the coast has eroded, 35% is stable and only 8% is accreting (growing). Artificial structures play a major role in promoting erosion along coasts. Coastal hamlets to the north of the harbour, including Kalapet, face consistent erosion, according to the report.
The steady erosion of Puducherry’s coastline, which originally extended almost 100 metres into the sea, is believed to have begun with the establishment of the fishing harbour in 1989, say environmentalists. The problem started in 1989 when the Puducherry government constructed two breakwaters. The construction of the harbour, with its wall projecting into the sea, blocked the movement of sand from the south towards the north. Though a sand bypassing system was provided at the harbour to regularly shift the sand from north to south, this has not been done, resulting in erosion along the northern side.
Now, however, the beachfront on the Promenade has extended in size more than a year after the Port Department launched a beach nourishment project recommended by the NCCR. The successful deployment of an artificial reef made of steel caisson (submerged structure) funded by the Ministry of Earth Sciences and implemented by NIOT and lowered into the sea opposite to the Chief Secretariat in 2018, helped in reducing wave activity and allowed sand to freely move towards the north to prevent erosion along the coastline.
While the beach has now returned on the southern side thanks to the artificial reef, the construction of sea walls in adjacent villages in Tamil Nadu has upset the equilibrium of the coast and aggravated erosion on the northern coastline of Puducherry.
“Sea erosion is noticed along many parts of India as well as other countries due to climate change and there is an emergent need to understand the impacts [of this] and to devise solutions for protecting coastal areas and for their adaptability to climate change. Eco-friendly techniques and “soft engineering measures” should be implemented along with beach nourishment for retaining of sand and to restore the ecological functions of the coast,” sources added.
The National Institute of Ocean Technology (NIOT) under the Ministry of Earth Sciences had submitted a Shoreline Management Plan to the Puducherry Government in 2015, and the revised plan would study the impact of erosion on the adjacent beaches and incorporate it with futuristic solutions to address and prevent the same.