Arichal Munai Beach lies at the eastern tip of Rameswaram Island, in southern India’s Tamil Nadu state, just past the abandoned village of Dhanushkodi. Looking out onto the Gulf of Mannar with nothing but sea between it and Sri Lanka’s northern shore, Arichal Munai offers a picturesque view of clear blue waters, and a rather less picturesque view of rocks bolstered by concrete.
Rows of such rocks have been installed along this coastline in an attempt to protect the shore from the waves eroding it. But critics say these hard structures are diverting the problem to nearby areas and causing the sea to creep closer to fishers’ hamlets in other parts of Tamil Nadu’s coastline.
“With the beach replaced by waters, we struggle to park our boats,” says G Anand, a local fisher at Dhanushkodi. The 53 year old once supported these defences but now regards them as a problem. “The population of turtles that comes to the shore for breeding has also been reducing over the years.”
In 2022, India’s highest environmental court ordered regional governments to try and avoid hard shoreline defences where possible, and to implement comprehensive plans to manage their coasts. But states and union territories are still building these concrete structures and many have failed to draw up such plans, in apparent defiance of the court’s ruling.
Going hard on coasts under threat
Beaches grow when currents deposit more sediment than they carry away. With this in mind, barriers called groynes are sometimes built out into the sea. Perpendicular to the shore, these protect beaches by catching and trapping sand that would otherwise be washed elsewhere. But groynes can also make erosion worse for nearby locations.
Probir Banerjee of the National Coastal Protection Campaign, a collective of environmental and fishing associations, explains the effect: “One part of the coast gets an excess of sand, and the other side on the down-drift is starved of sediment. The side that is starved of sediment erodes as long as fresh input of sand is not provided.”
Many experts therefore discourage use of groynes and sea walls in favour of “soft” defence strategies, such as replenishing lost beach sand and encouraging sand dunes by planting grass. Hard structures on beaches can also have a disastrous effect on marine flora and fauna. They have the potential to damage habitats that support fish, crustaceans and shellfish, and to prevent sea turtles from nesting.
Although natural solutions are more effective, securing government funding for them remains challengingAnonymous senior official at the Department of Fisheries
Much of India’s thousands of kilometres of coastline are eroding, fast. The National Centre for Coastal Research (NCCR), a government body, estimates that 33.6% of the shore is vulnerable to erosion, while only 26.9% is growing. Some regions are more vulnerable than others: over 50% of the coasts of West Bengal and Puducherry are eroding, according to NCCR data. Coastal erosion is a consequence of natural processes, climate change and anthropogenic activities. Hard structures built to solve it might not be helping and are known to worsen erosion near where they are installed, by starving areas of sediment.
“Hard engineering measures have actually worsened erosion,” says a senior official at the Department of Fisheries (speaking on condition of anonymity). “For example, after groynes were installed at Chennai’s Thalankuppam Beach, the shoreline has receded by 12 metres, with water now reaching the main road. Although natural solutions are more effective, securing government funding for them remains challenging.”
Despite concerns over ill effects, last year Chennai’s government constructed two large groynes at the coastal hamlet of Karikattukuppam, extending 120 metres out to sea. The work was in response to pleas from fishers, whose hamlets are threatened by the sea.
It is not just Chennai putting its faith in hard engineering. The Maharashtra government has constructed a large sea wall at Mumbai’s Aksa beach. And in October 2024, Kerala’s irrigation department started building eight groynes in the Poonthura region. Meanwhile, in Tamil Nadu’s Chengalpattu district, groynes, sea walls and artificial barriers were constructed across at least 10 coastal villages in the past year, local sources tell Dialogue Earth.
Green court’s soft approach
These constructions violate a legally binding ruling by India’s green court, the National Green Tribunal (NGT). In 2022, it directed Indian states and union territories to adopt soft solutions, such as beach nourishment, instead of hard structures like groynes.
An example of “soft” coastal engineering, beach nourishment entails bolstering a shoreline against erosion by replenishing its sediment. Ideally the sediment comes from local accreting (growing) beaches. If not, it runs the risk of transferring the erosion problem elsewhere. As the sediment may be coarser or finer, it can also make habitat unsuitable for some local species.
Beach nourishment is considered more sustainable than building artificial structures like seawalls. At its best, it not only bolsters a shoreline, but can create new natural environments, bury unsightly hard engineering structures, and protect sediment volumes.
Stressing that hard measures only transfer the problem of shoreline change, the NGT told states and union territories to prepare and update their shoreline management plans within six months. Two years later, there has been little progress.
Puducherry has implemented (and is already revising) a shoreline management plan, as directed by the NGT ruling. But neither India’s three other union territories nor its nine coastal states have followed suit.
Governments, engineers and fishers often prefer hard structures because some experts say they immediately arrest local erosion. This may seem an easy option for governments, which can base their designs on existing examples for such work, simplifying the process. By contrast, softer measures require careful scientific study of local conditions.
“There is no assessment, no design and no consultation with the stakeholders. These structures are seen as a solution for every beach, regardless of its character,” says K Saravanan. The fisher and activist filed a case with the NGT in July 2024, which challenges Chennai’s decision to construct Karikattukuppam’s groynes without a shoreline management plan.
Fragile and fast eroding
Regional governments have chosen agencies to help them develop shoreline management plans. The National Centre for Coastal Research (NCCR) is tasked with preparing and updating plans for Tamil Nadu, Andhra Pradesh, Kerala and Puducherry.
The NCCR’s director M V Ramana Murthy says draft plans for Andhra Pradesh and Tamil Nadu are with the Ministry of Environment, Forests and Climate Change for final approval. The Kerala and Puducherry plans are still being drafted.
“These plans highlight the importance of nature-based solutions to prevent coastal erosion,” says Ramana Murthy. “However, state governments are often reluctant to adopt these methods due to their high maintenance and time-consuming nature, leaving the extent of their implementation uncertain.”
He says the NCCR has mapped the settlements along India’s entire coastline to determine the most suitable erosion-control methods: “For densely populated areas, we recommended hard engineering solutions if absolutely necessary. In moderately populated regions, we opted for hybrid approaches. While for less populated areas, we prioritised nature-based solutions. We also considered erosion rates and identified vulnerable zones to guide these decisions.”
The petitioner K Saravanan says the NCCR has been relying too much on satellite imagery when it should be conducting on-the-ground surveys. He also says plans are being made without proper consultation, something fishers associations in Tamil Nadu also told Dialogue Earth.
The NCCR denies these allegations, with Ramana Murthy saying: “We have been getting inputs from the fisheries associations.”
Finding a way forward
Coastal erosion is an alarming problem in the wider region, too. A 2017 estimate suggests that around 35% of Indonesia’s coastline is experiencing a moderate, high or very high erosion rate; 29% of Malaysia’s coastline faces erosion; and 50% of mapped areas in the Philippines are retreating. Some countries are taking informed action. Malaysia’s Integrated Shoreline Management Plan is being implemented state-by-state following stakeholder engagement. The Philippines has been making similar moves.
By comparison, several sources consulted by Dialogue Earth fear India is lagging. They say state-level plans addressing the country’s coastal erosion will require buy-in from the national government to secure swift implementation. Crucially, the education of local communities will galvanise sustainable solutions. Experts and fishers say that in most cases it is local fishers themselves who call on their government to construct hard defences.
“When such structures are constructed in one coastal hamlet, the erosion transfers to the adjoining village. And thus, they should be constructed here as well,” says S Sathish Kumar, a fisher in the coastal hamlet of Alamparai Kuppam, Chengalpattu.
As regional governments consider the development and implementation of comprehensive shoreline management plans, many of India’s sandy beaches face an uncertain future.
Ganeshan V, a fisherman in Cochin, Kerala, says: “Water is already reaching my house. All I can think about is stopping it. I don’t have the luxury to be a good person and worry about erosion in the next hamlet, or the environmental effects of putting up these hard structures.”
