IT was early morning of the first day of August. Suddenly, a guard noticed a large crack on NH 117, at a distance of barely ten metres from Ganga, at Diamond Harbour, the last important town of South Bengal on the left bank of the river. The locals acted with alacrity to stop the traffic on the road. Within minutes, the crack widened, and on a stretch of about 80 metres, half of the road caved in.
It did not happen on a day of heavy rains. In fact, rains are playing truant in South Bengal this year, encouraging chats on global warming and ‘extreme weather conditions’. After the subsidence, the politicians started their regular blame game. The heavyweight TMC MP Abhishek Banerjee blamed it on erosion of Ganga, while CPI(M) bigwig Sujan Chakrabarty identified beautification work on the river bank as the culprit. A few Calcutta papers did not report the incident of subsidence on page one the next day. It was business as usual.
The incident should have acted as an eye-opener. But no one was interested to look at the grim bigger picture that points at a large-scale environmental disaster. We have all the information, but we love to treat those as disparate pieces.
What are those pieces of information? Check them out. A few kilometres upstream of Farakka, Ganga is shifting to its left, making the possibility of outflanking the barrage real. Fifty kilometres downstream of the barrage, near Dhulian, the mainstream (Padma) that goes to Bangladesh and the branch (Ganga/Bhagirathi) that flows through India are reducing the distance between them as the branch is inching forward towards the main stream. The erosion of the left bank of Ganga gobbled down 356 square kms of landmass and displaced 80,000 people of Murshidabad district in the last decade of the last century. Twenty years later, the river that has fallen victim to heavy sedimentation of the bed is wrecking havoc in Nadia (the district in the south of Murshidabad). And now the erosion has spread secret tentacles up to Diamond Harbour, which is 90 kms south of Shantipur, the last town up to which erosion of Ganga had reached so far.
Meanwhile, the hungry tides are advancing as the sea is rising, that too at a higher rate than global average. In another 50 years, the sea will devour the Mangrove forests of the Sunderbans, the last coastal habitat of the Bengal Tiger. With the rise of the sea and the depleted volume of water in the rivers, the level of salinity is increasing in South Bengal. Mangroves that survive only in saline soil are taking roots at the bank of the rivers up to Calcutta and even beyond!
Now, if we read together all the information, we come across some grim possibilities. If Ganga outflanks Farakka by shifting to an old course (as Kosi River did in 2008 flooding 8 districts of Bihar and displacing nearly 30 lakhs people), or the two streams merge at Dhulian, permanent damage of unimaginable magnitude will be done. Even otherwise, the rivers of the Gangetic plains are choking. As the flow of water slack off, the rivers eat away the bank and become more slack. Consequently, a century later, large turfs of northern Gangetic plain will turn swampy. At the same time, in future, saline water will make deeper inroads and may destroy large swathes of multi-crop lands in southern part of the plain.
Many urban areas, including Calcutta itself, are under threat as Ganga is not only eroding banks, but its water is seeping into the soil adjacent to it. In the 90s, a foreign research team felt river water was seeping through the ground, making towns like Diamond Harbour unstable. Nobody cared to listen. Now the river-side of the town has turned fragile. The same fate is awaiting the riverbanks of tens of towns on the left bank of the river. The list includes the city of Calcutta All together, Bengal is staring at all round environmental disaster, from north to south. But nobody except some environmentalists is concerned.
The Rage of the Ganga
In 1975, when Gangabhavan was constructed in Malda district, Ganga flowed five kilometres away from it. That was the time 2.24 km long Farakka barrage started operating. Soon, the blues struck the southern part of Malda district in the form of recurrent floods. On the night of 5th September, 2003, the river devoured Ganga Bhavan situated some kilometres upstream of Farakka. In less than three decades of Farakka barrage’s existence, the river expanded five kilometres on its left at a point which was just a few kilometres upstream of Farakka.
IN post-barrage days, while Malda was affected by the main stream, Mursidabad had to endure erratic behaviour of both the mainstream (Padma) at the east and the branch (Bhagirathi) dividing the district from the middle. The people of this Muslim majority district suffered heavily, and large scale migration of male workers started from the ‘90s. Some small towns like Akheriganj have already been washed out. According to last available statistics, more than 25 lakhs people still reside along the banks of Ganga in Murshidabad district, and half of them are in danger of losing their homes over next two decades. Not only villages, but many towns are in danger of being submerged.
ONE such town is Dhuliyan that still hosts 230 thousand people. Kalyan Rudra, a r,iver-expert, pointed out in 2010 that this centuries-old town is likely to disappear into the Ganga in the next few decades. So far, about 250 square kms of land has been lost in Malda district, and more than double of it in Murshidabad district. The mainstream of Ganga and the Bhagirathi have reduced the distance between them by 1.3 kms near Jangipur in last two decades, and are flowing keeping a distance of another 1.3 kms between them. If they merge, hundreds of square kilometres will go under water.
At places Bhagirathi and smaller rivers like Jalangi are meandering so much around small areas that someday such areas are likely to be inundated entirely. While in Murshidabad the erosion continues, the main theatre of destruction has now shifted to next district in its south, called Nadia. Here, in Chanduria gram panchayat area, five villages have gone under water, and the rest eight under the GP are likely to be inundated in a few decades. That will wipe out a whole gram panchayat from the map of Bengal. Some villages like Char Kumaripara, which were earlier connected with roads, are gradually turning into islands. According to district administration, about one lakh people living in 94 panchayats have been displaced in this century as their lands were eaten away by Bhagirathi.
It is not only Bhagirathi that is causing the damage. All rivers between Padma and Bhagirathi are connected with these two streams of Ganga, and they behave in the same way as their mother river does. That makes more than 1000 kms of riverbanks and about 3 thousand square kilometres of land) in Murshidabad and Nadia fragile. In a state that has an average population density of 1028 per square kilometre (second highest in India), the scenario is fraught with dangerous consequences. As it seems, the erosion is moving southwards slowly but certainly. That means in another 20 years, the erosion may affect North 24 Parganas, the district lying at the south of Nadia and north of Calcutta on the left bank of Ganga. It is also the most densely populated part of Bengal. Perhaps, within 50 years from now, Calcutta too will start losing densely populated localities.
The advancement of the Sea
A day after the incident of subsidence of the highway at Diamond Harbour, the hungry tides of the sea crossed the guard-wall and inundated the road by the sea at Digha, a major tourist attraction in Bengal. It was a night of unusual high tide. The tourists were elated at the scene of huge waves crossing the wall, quite oblivious of the fact that this was too ominous a sign for the coastal town. Thirty years ago, the town did not need any protection of boulders or guard-wall. It had a natural coast like any other coastal towns. But even then the scientists and engineers knew in four decades from then large part of the town would go under water. So they laid huge boulders and made the guard-wall that so far have protected the town. “But now it seems if we do not start constructing eight to ten feet high concrete walls along the coast,” says a government engineer, “in 50 years the sea will claim a large part of Bengal coast, including the coastal towns.”
The rising water is devouring the islands close by the shore bit by bit. Sagar, the biggest island was a single mass of solid land. The sea first broke it up into many islets like Ghoramara, Lohachara, Subarnabhanga and unnamed small chunks. Now, Lohachara and Subarnabhanga have gone under the sea. Ghoramara too will have the same fate in a decade or two. On its western side, Khasimara island too has disappeared. A report by the National Centre for Coastal Research (NCCR), Ministry of Earth Sciences, said that West Bengal recorded the maximum coastal erosion (63%, followed by Puducherry 57%, Kerala 45%, and Tamil Nadu 41%) among all Indian coastal states. But nothing much has been done to face the reality.
In 50 years from now, Bengal Tigers are likely to go missing from Bengal too. Along with a large part of Bengal’s coast, vast lands of the Sunderbans are likely to be claimed by hungry tides. While the rest of the coast can delay the doomsday by laying boulders and constructing walls, the Sunderbans or the islands cannot be saved unless well-planned humongous effort is undertaken now.
As of now, during the low tide, the water recedes from the Sunderban. But 50 years later, from a vast area of the forest, which has shrunk and stands at about 5 thousand square kilometres now, will remain inundated all through the day and night. Consequentially a vast area beyond it will become saline, particularly because all the rivers of the coast, including the Ganga, flow upstream when the high tide comes in the sea. Besides, South Bengal rivers like Matla, Saptamukhi, Jamia and Gosaba have lost their fresh-water connections. In future, it will affect thousands of square kilometres agricultural lands of both North and South 24 parganas. The Mangrove will advance northwards due to salinity of the land, creating new zones of conflict between man and nature. The great-grandchildren of 88 surviving tigers in Indian part of Sunderbans will also try to shift to northern parts, as hunting a prey in submerged land is impossible. Probably they will have to be killed to protect human beings, as these natural man-eaters cannot be relocated to somewhere else (except the zoos). Lives of millions of people will also be thrown out of gear.
For the sceptics who think these are too far stretched, here are some statistics. According to research organisations like CPCB, CICFRI, Jadavpur University’s Oceanographic Studies, and Department of Urban Welfare of the State Government, the salinity level is increasing even 100 km upstream of the estuary. The salinity level at Uluberia, a town on the west bank of Ganga110 kms north of Sagar island, increased from 0.028 ppt in 1985 to 0.132 ppt in 2013. At Barrackpore, 140 kms upstream from the estuary, while the salinity level was 0.019 ppt in 1985, it rose to 0.055 ppt by 2005. This level of salinity is enough for mangrove, that is why all along the riverbank from the sea to Calcutta and even beyond, mangroves are taking roots in the saline land in last few years. The Botanical Garden at Shivpur, Howrah, was trying plantation of mangrove, according to Garden in-charge M U Sharief, for last 50 years. It always failed. But now, as mangroves are growing on their own, the Garden authority have dedicated a 4-acre plot to grow a mangrove forest (with trees like garjan, hargoja, ora, panlota).
No major remedial initiative
In a democracy, political parties come to power for five years. They remain obsessed with those 5 years after which they will have to face the people again. In this scheme of things, fifty years is too long a timeframe, and a century is unimaginably long for any planning. The blues of Bengal, however, will be full-blown not in a few years (unless Ganga suddenly outflanks Farakka barrage or the two streams of Ganga merges after the barrage). It will unfold over many decades.
Southern Bengal is not suffering this fate only because of high rate of rise of sea level. The reduced downstream transport of sediment thanks to Farakka barrage is also a reason behind it. The sea is pushing in more saline water during the high tide, and that is seeping into the adjacent land. Interestingly, while the Kolkata port had to dredge 6.4 million cubic metres per year before the barrage was constructed, it now needs to annually dredge out 21.18 million cubic metres.
Two years ago, Bihar Chief Minister Nitish Kumar demanded the Farakka barrage be demolished as it is causing widespread flood in Bihar. No doubt, the barrage has failed to fulfil its goal in Bengal too, while the collateral damage it caused is killing the Gangetic plain. The ecology of the Gangetic plain in eastern side of Bengal is already under severe strain. But, now that the rivers have become sluggish in Bengal, no one knows what would be the impact of decommissioning the barrage. The ecology of Calcutta and many other towns have been disturbed by illegally filling up the ponds over last forty years. If the decommissioning increases the volume of water in Bhagirathi, many such towns including parts of Calcutta and vast agricultural land may get inundated. If it reduces the flow, not only Calcutta port will be over, the Gangetic plain too will lose a large share of its fertile lands.
So, what is to be done? There is only one solution. If the river system is to be rejuvenated, it can be done through massive scale of dredging, the cost of which will be huge. A permanent Commission with constitutional sanction, must be formed with experts from all related fields and representative of state and central governments to oversee the process. It should look into the problems in a holistic manner and suggest other remedial measures. Its recommendations should be binding. It has to done now, otherwise it will be too late, like what happened in North Bengal. There, at the foot of Himalaya, a large part of Alipurduar district including the Buxa Tiger Reserve is likely to be inundated in another ten years. The river-bed of Jayanti that flows through the northern part of the district has risen whopping 20 feet (yes 20 ft) in 30 years! It deposits dolomite mixed pebbles from Bhutan where large-scale mining is going on. The experts advised large scale dredging, but the Supreme Court did not allow it within Buxa Tiger reserve, as it would have disturbed the tigers. But now, not a single tiger is there in Buxa. It is doubtful whether mechanised dredging will be able to clean it anymore.
If nothing is done, whole of Bengal will suffer the fate of Buxa Tiger reserve one day.
State Scan / West Bengal / Environment / by Diptendra Raychaudhuri