5 months ago
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In August 2008, Bihar experienced 1 of the worst floods successful astir 5 decades erstwhile the Kosi River breached its embankment astatine Kusaha successful Sunsari territory of Nepal, sidesplitting much than 400 radical and displacing thousands. A staggering 33 lakh radical were affected astatine the highest of the flood successful Bihar.
Indeed, the Kosi River breaches the walls of its embankment every fewer years, imperilling lives and livelihoods, and earning it the sanction ‘river of sorrow.’
In the eastbound Gangetic plains and the adjoining floodplains, rivers person overflowed during the monsoons for centuries, causing catastrophic floods. The Kosi originates successful Tibet and Nepal and aboriginal joins the Ganga successful Bihar. Often called “sapta Kosi” due to the fact that of its 7 tributaries, it is simply a fragile and dynamic stream that people carries ample quantities of sediment. Over the years, the stream has shifted its people by respective kilometres, subsequently triggering floods.
Committee report
According to a study of the People’s Commission connected the Kosi basin, an autarkic commission, the stream has moved 120 km westwards successful the past 250 years owed to a dense earthy sedimentation process. Experts suggest the operation of a barrage successful Nepal successful the 1950s, followed by an embankment successful Bihar, has importantly altered the river’s earthy flow.
Embankments are artificial structures made of earth, stone or concrete, designed to power h2o travel successful flood-prone areas. These structures are made to endure the effects of gravity, h2o pressure, and different outer forces and are expected to stay unchangeable implicit time. While they are often promoted arsenic an perfect solution to support settlements and heighten agriculture, experts person agelong warned of their limitations.
In 1951, the G.R. Garg Committee report of the Central Waterways, Irrigation and Navigation Commission warned against specified projects. It was appointed aft Assam decided to physique an embankment, hoping to forestall floods during the monsoon. The study observed that the 2 main functions of a river, providing onshore (by eroding and depositing) and draining its basin, are disrupted by embankments. It further cautioned that these structures are utile lone erstwhile the stream carries little silt; different they could bash much harm than good.
Rather than wage heed to these warnings, however, the Assam authorities proceeded with gathering embankments on the Brahmaputra River. While the thought was elemental — to forestall floods — its effects were counterproductive. In Assam, particularly, coarse silt and soil were deposited by rivers connected the banks, affecting agriculture. Local communities lived successful changeless fearfulness of a breach. Siltation reduced the river’s extent and made navigation much difficult.
Flood control
“The bluish rivers transportation a batch of silt. So if you embank them, the stream keeps getting higher due to the fact that of the accumulation of silt,” said E. Somanathan, caput of the Centre for Research connected the Economics of Climate Change, Food, Energy and Environment. “And due to the fact that each monsoon the silt adds up, an embanked stream aft a fewer years turns dangerous, adjacent though initially it provided immoderate protection.”
This is wherefore specified incidents related to the Kosi aren’t isolated: the stream breached its embankment in 1963, 1968, 1971, 1980, 1984, 1987, and successful 1991, before it breached again successful 2008 and 2024.
Almost precisely a twelvemonth ago, erstwhile the Mahuli tributary of the Kosi River entered India and deed the Kosi barrage, the quantity of the silt successful the stream increased, causing devastating floods. Every year, the magnitude of silt threatens locals and submerges immense tracts of cultivation land.
The repeated breaches rise an important question: should embankments beryllium considered flood-control structures astatine all?
Influent and affluent rivers
“Whether embankments are indispensable depends connected the aim,” Rahul Yaduka, a postdoctoral student moving connected the WATCON Project astatine The School of Oriental and African Studies, London, said. “If improvement is the aim, past embankments volition service the intent due to the fact that you tame the river. But radical person ever been surviving with floods for centuries.”
When the British noticed that the Kosi River was shifting its course, they recovered it hard to power it, and decided to physique an embankment to power the flow. But the effect of this workout was water-logging extracurricular the embankment, causing floods for those who unrecorded betwixt the embankment,” Dr. Yaduka added.
On the different hand, Bindhy W. Pandey, manager of the Centre for Himalayan Studies astatine the University of Delhi, argued that embankments tin play an important relation successful rivers successful the occidental Himalayan portion arsenic they are little flood-prone and geologically much stable. He, however, cautioned against constructing embankments connected the rivers successful the eastbound Himalayan portion arsenic they were susceptible to breaches, geologically weaker and much prone to landslides.
“Rivers draining successful the westbound are influent, meaning that arsenic the stream flows done antithetic States, the precipitation decreases. Whereas the east-flowing rivers are affluent, that is, the magnitude of precipitation increases successful the people of time,” said Prof. Pandey. He added that operation successful specified geologically anemic regions indispensable beryllium paired with changeless monitoring and a transparent rehabilitation process for the displaced people.
His statement circled backmost to Dr. Somanathan’s warning: that embankments whitethorn connection short-term extortion but often unfastened the doorway for semipermanent vulnerability.
‘Not a viable option’
“The US has dismantled embankments and allowed the flood to happen. When we physique much infrastructure that alters the river’s course, the stream furniture keeps expanding silt, but floods without embankments are overmuch milder. If an embankment is built, past we request to support raising its height. But that requires finances,” Dr. Somanathan said.
The alternate that helium projected is to ‘learn to unrecorded with floods’.
“When we bash that, we are allowing the stream to enactment arsenic a earthy drainage system,” Dr. Somanathan said. Mahendra Yadav, subordinate of the Kosi Nav Nirman Manch Movement, besides stands by the conception of ‘living with floods’ but believes this tin hap lone if radical betwixt the Kosi embankment are trained with aboriginal informing systems and provided rehabilitation outside. “The solution that tin beryllium offered to radical is to rehabilitate them extracurricular the embankment due to the fact that if the embankment is blocking them, they cannot get out, adjacent with aboriginal informing systems.”
“For India, an embankment is not a viable enactment due to the fact that we don’t person the infrastructure to support it,” Dr. Somanathan said. But arsenic the embankments are a world for galore rivers successful bluish India, Dr. Yaduka suggested that 1 has to “identify ways to marque them amended and stable. Along with that, paleochannels (abandoned ancient stream oregon watercourse channels) should beryllium revived truthful that h2o is distributed.”
Mr. Yadav besides suggests the betterment of palaeochannels, which incorporate the h2o good wrong their basins, preventing floods.
Tall promises
Ahead of the Bihar predetermination this year, the National Democratic Alliance (NDA) promised “flood to fortune” successful their predetermination manifesto for the radical of Bihar. The conjugation assured residents that if elected to power, the recently formed authorities volition initiate the river-linking project, embankments and canals nether the “flood to fortune” exemplary to beforehand agriculture and fisheries, according to the ‘Sankalp Patra’ released jointly by the BJP and NDA.
Though this committedness carries with it a code of governmental optimism, the State’s geography is analyzable and requires a deeper knowing of the long-standing ecological realities, including sedimentation and siltation. The river-linking task successful question is the Kosi-Mechi project, which aims to widen the EKMC (Eastern Kosi Main Canal) up to the stream Mechi, a tributary of the stream Mahananda, chiefly to supply irrigation to the water-scarce portion on the Mahananda basin during the kharif season. However, successful reality, if it rains adjacent the Kosi catchment area, the monsoon reaches Mahananda successful a time oregon 2 and determination is hardly immoderate request for h2o during the monsoon.
“But if the contented [flooding] was to beryllium solved by an embankment, past determination should person been nary floods astatine all, but that is not the case. If the river-linking task is completed, 5,247 cusecs of other h2o volition beryllium diverted towards the Mechi River. But successful the floods past year, Kosi stream carried astir 6 lakh cusecs of water. So, we are not reducing the flood h2o by gathering embankments oregon by linking the rivers,” Mr. Yadav explained.
Every year, Moreover money has to beryllium spent connected raising the embankment, but that is not a sustainable solution, helium added. “In fact, it is simply a luxurious choice. Even though wealth is spent, does it really sustain? And much importantly, who is benefiting from it? The locals stuck [with] the embankment look the wrath without immoderate rehabilitation facilities.”
“With the embankment, the flood has accrued astir 4 times,” Mr. Yadav said. He added that desilting should beryllium done according to technological methods.
Dr. Somanathan powerfully argued that embankments disturb the ecological integrity, groundwater, and biodiversity, and expressed anticipation that the sermon would alteration from flood-control to flood-resistance.
For the families that suffer their homes each twelvemonth erstwhile a stream swells, the embankment is some a menace and a promise, a enactment drawn against quality that ne'er seems to clasp for long. But arsenic the Kosi’s communicative illustrates, each clip an embankment is raised, the stream is speedy to reclaim its domain.
