The Challenges Of Embankment Construction In The Sundarbans
Sundarbans inhabitants have faced climate-induced displacement for decades. There have been several waves of migration within the Sundarbans, often on the same island, to avoid flooding from embankment breaches, tidal bores and storm surges (Photo by Subhrajit Sen/Mongabay)
Thirty-five-year-old Ramaprasad Maiti, a resident of a Sundarbans island, has moved houses 17 times in his lifetime as erosion tore them down and washed them into the river one by one. On Ghoramara island, near the confluence of the Hooghly river and the Bay of Bengal, Maiti is certain that more people living near the banks will have to move further inland if the existing earthen embankments are not strengthened with boulders.
“Earthen embankments are of no use. Every monsoon, we find the river mightier than the previous year. Some acres of land and houses go to the river every year. This island can only be protected if the embankments are strengthened with boulders,” Maiti told Mongabay. He has had no income since the storm surges associated with cyclone Yash in 2021 destroyed his betel plantations.
A mix of hard-engineered structures and soft structures like mangroves can act as a barrier to shoreline erosion. But eroding shorelines in the Indian Sundarbans in the Bay of Bengal also take down mangroves with them. Experts have flagged the importance of continuously monitoring these ecosystems that are at risk due to climate change, coupled with the legacy of historical shoreline changes from human activities. Ever-rising greenhouse gas emissions are supercharging extreme weather events across the planet including cyclones in the Bay of Bengal, imperilling mangroves and concrete protective structures. The cluster of low-lying islands is in the spotlight with countries agreeing to put loss and damage financing on the official agenda of the ongoing UN climate summit (COP27) in Egypt.
In erosion-prone Ghoramara, the population has not gone through significant changes in the last 30 years – it stood at 4,972 in 1991, 5,236 in 2001 and 5,193 in 2011. This population stagnancy has been attributed to outward migration to the larger neighbouring islands of Sagar and Kakdwip.
In 1922-23, Ghoramara consisted of a group of three adjoining islands. The main island of Ghoramara sprawled over 18.5 sq. km. and its islets, Khasimara and Lohachara, spread over 3.2 sq. km. and 8.7 sq. km., respectively. Lohachara disappeared in the early 1990s, and Khasimara in the late 1990s. Ghoramara was only 3.59 sq. km. in 2020, having lost three-quarters of its size in just a century.
Are They Out Of Options?
Mousuni sits at the mouth of the Bay of Bengal, between rivers Chinai and Muri Ganga, southeast of Ghoramara, and facing the open sea. Here, residents of Salt Gheri village showed how the existing embankment is the fourth bank in less than a decade – the previous three lost to the advancing sea. Between 1970 and 2020, the island lost 7.3 sq. km., nearly a quarter of its size.
Resident Swapan Koyal said their family was forced to move residences five times, retreating further inland each time. The last house they abandoned is still standing but precariously so, the soil beneath it having been displaced. According to him, erosion weakens the embankment several times a year, and the river wreaks havoc even during the normal high tides. “It will be very difficult to survive here unless the government creates pucca (concrete) embankments,” he told Mongabay.
Maiti and Koyal are not the only ones who believe that nothing but concretised embankments or those supported with boulders can save them. Throughout these two islands, people said that pucca or concretised embankments were their priority demand.
Ghoramara has reported many problems related to erosion, rising sea levels, and harsh weather conditions, frequent flooding, and increasing water salinity resulting in a higher chance of droughts. Not all tube-wells function and even that groundwater is saline. Increasing soil salinity further reduces agricultural production here, where residents are dependent on monocrops, mainly rice.
“Salinity in the ponds is so high that people find them unfit even for bathing. However, the one problem we want the government to solve first and foremost is erosion,” said Sukhdeb Maiti, a grocery shop owner in Ghoramara.
In Mousuni, Bholanath Koyal, who runs a tourist camping facility near the narrowing beach, said that every monsoon is ridden with anxiety as the raging Chinai and Muri Ganga rivers keep threatening displacement. “We do not need rice at subsidised prices. We’ll arrange for our own food. But our main need is an embankment. Without pucca embankments, there will be no Mousuni.”
According to Nirmal Maiti, a fisherman, the people of Ghoramara island are running out of resources trying to rebuild homes. “Homes have to be rebuilt every two or three years. Where is the excess land in Ghoramara to buy when agricultural land is lost?” he asked. In Mousuni, Baliara village resident Sheikh Kabiruddin echoed Maiti’s worries. “We are in deep trouble every time there is a storm. Only a concrete embankment can make the area habitable,” he said.
Embankments Aren’t Enough For The Sundarbans
A 2021 report by an expert committee constituted by the West Bengal Environment Department acknowledged the locals’ needs. However, it said that embankments may not be enough.
“The armoured or concretised embankment, be it along the river bank or the sea-front, cannot prevent overtopping of the swelling water. In all vulnerable stretches, a second line of defence in the form of circuit/parallel embankment is absolutely essential and should be treated as a priority project to ensure the safety of the people,” stated the report. It also cited the importance of parallel dykes with cross-embankments placed at regular intervals in such areas. However, the proposed solution is resource-intensive and will require space that may not be available.
In Mousuni, such embankments would require displacement and rehabilitation of 605 households, the report estimated. In Sagar, which too is suffering from a land crisis, 630 households will need to be relocated.
West Bengal’s Sundarbans Development Minister Bankim Hazra told Mongabay that such embankments would be impossible without financial help from the Union government. “The state government obtained a loan from the Rural Infrastructure Development Fund (RIDF) last year, and it was utilised to install concretised embankments on some parts of sea-fronts. However, there are still 184 vulnerable spots stretching across 400 km. We have repeatedly asked for funds from the Centre but are yet to hear anything positive.”
Scientists who have been studying changes in the Sundarbans for over two decades told Mongabay that erosion is accelerating on the sea-facing islands and that preventing further loss of land is challenging. “Concrete embankments can delay erosion but cannot fully prevent it in the long run. West Bengal’s entire coastline is retreating inland naturally, about 30-40 metres per year in some places. This is not completely resistible,” said Sunando Bandyopadhyay, a professor of geography at Calcutta University.
Tuhin Ghosh, a professor at Jadavpur University’s School of Oceanographic Studies, said that strengthening embankments with boulders will not be of much benefit for Sundarbans islands like Ghoramara. “There is a tectonic shift towards the southwest. The river is shifting from west to east. That’s why the main area of erosion has shifted from west to north, northwest, and northeast. The erosion will further shift eastwards,” he said.
According to Ghosh, since the entire Sundarbans coastline is retreating inland, the government is finding it difficult to acquire space for new embankments. “But what kind of embankments have we been building all along? Narrow, vertical, with steep slopes. Such embankments will collapse every year. Proper embankments need to be wide, with gentle slopes. Brick-built embankments with layers of concrete, or employing the methods of bio-engineering by using geo-textiles, can solve the problem to some extent,” he said.
Notably, the central government had sanctioned Rs. 5,032 crore in 2010, in the aftermath of the devastation of cyclone Aila in 2009, to reconstruct 778 km. of embankments. Of this, according to Hazra, only Rs. 1,339 crore was ultimately released and it was used to concretise 94 km. in 2011 and 2014-15.
The remaining funds were not released by the central government, citing delay by the state government in completing the first phase.
According to Kanti Ganguly, a leader of the Communist Party of India, who served as the Sundarbans Development Minister from 2001 to 2011, the five-year-long project expired in 2014-15, by which time only a part of the work could be completed, owing to a delay in the land acquisition process.
However, in 2018-19, another Rs. 117.11 crore grant was approved by the Ministry of Jal Shakti under the same scheme.
A local MLA of the ruling party, the Trinamool Congress, who does not want to be identified, said the biggest problem with building concrete embankments in the Sundarbans is the lack of proper land records. He said that given the decades-old history of internal migration prompted by erosion and climatic impacts, those who currently live near the embankments are not the original owners.
“Land has changed hands many times, but the government records have not been updated due to a lack of the practice among locals to formalise land transfer. Therefore, those who occupy these lands at present are often not eligible for compensation because, on record, the land belongs to the previous owner. They don’t want to part with their land without compensation,” the legislator told Mongabay.
Even a 2020 report of the state government prepared in the aftermath of cyclone Amphan noted, “Even ‘Aila bandh’ (embankment) could not be completed in many areas due to inability to acquire land for the embankment purpose, hence the existing dyke continued to remain weakened.”
The report said that since the reconstruction of embankments breached by cyclone Aila started a few years after the cyclone, the lived experiences had started fading from public memory. “Hence the response of giving away the land for Aila bandh was not spontaneous everywhere. However, this time the work should start immediately to have consensus building within the community,” it said.
While land and monetary concerns appear to question the feasibility of erecting embankments for the islands of Ghoramara, Mousuni, and Sagar, the clock is ticking.
“Those living on or near the embankments can’t be at peace. Who knows, which part of the bank is going to go under the river next,” said Sheikh Toukir, who lives on an embankment in the southern part of Ghoramara.
Sheikh Saidul Islam, a resident, and farmer by profession says, “Those who could afford to leave have left the island. The economic condition of the rest of the people of Ghoramara does not allow them to buy land or a home outside.”
