Kosi submerges Bihar

Every once in a while, nature reminds humans it is the boss. The Kosi, which gathers water from some of the highest mountains in the world, including Everest, and enters India in north Bihar, has changed its course and shifted over 120 km eastwards, going back to a course it had abandoned more than 300 years ago.In the process it has rendered useless more than 300 km of embankments built to control its ever-angry waters. The effect has been enormous, inundating numerous towns and villages that had not seen such floods for decades.It is a Katrina moment in Bihar — nobody expected Hurricane Katrina to breach the levees protecting New Orleans, that too in 53 places flooding 80% of the city and leaving a trail of death and destruction. Just like the people of New Orleans, who felt secure because the levees were there, the people of Madhepura, Araria and Supaul districts had faith in the embankments to keep the waters from flooding the adjacent plains. But they had not reckoned with the enormous pent-up force unleashed by 51 billion cubic metres of water. It broke through the embankment just after the barrage at Bhimnagar — and swept into its old course.On Tuesday, panic swept through the flooded Purnia and Araria districts as rumours of pressure on the Raja bund in Nepal began floating around. Thankfully, the administration quickly allayed fears and said a crack had already been repaired.The Kosi is called the Sorrow of Bihar because among all the fast-flowing rivers speeding into Bihar, it is the most dangerous. It carries over 81 million tons of silt every year in its roiling waters. And, it is a young river, not having matured enough to settle on a course. As it enters the northern plains the incline drops off, and the water starts slowing down. Over the years silt gets deposited giving Kosi its braided shape — it has several channels that diverge and again merge, like a braid, as the water tries to find new ways to go further. As it shifts it leads a deposit of sand, which renders the land barren. Seen from a satellite, the area looks like a conical fan. Created by hundreds of years of shifting, it is the largest such cone in the world, covering an area of over 15,000 square km. The tip is near Chatra on the Nepal border. The cone is made up of the various courses of Kosi and the land in between. The Kosi used to wind its way on the eastern-most course. But as the silting raised the level of the bed, it kept shifting westwards. However, because there is an incline from the west to the east, the waters couldn’t move westward any more and have returned to the east.Experts argue that the embankments allowed too much silt deposition in a shorter stretch, leading to devastation. In other words, young Kosi is not being allowed to grow up and settle down.


1963 Dalwa–Nepal

1968 Jamalpur–Darbhanga

1971 Bhatania–Supaul

1980 Bahuarwa – Saharsa

1984 Nauhatta–Saharsa

1987 Samani–Saharsa

1991 Joginia–Nepal

2008 Kusaha–Nepal

FLOOD OF FURY Districts Hit: Supaul, Madhepura, Saharsa, Araria, Purnia and Katihar Population Hit: 21 lakh in 417 villages Worst Kosi flood was in: August 1954 with a magnitude of 8,50,000 cusecs Kosi barrage was designed for a peak of 9,50,000 cusecs. The massive breach of Aug 18 indicates the threshold was crossed Kosi, a transboundary Nepal-India river, drains an estimated 69,300 sq km before meeting the Ganga in Bihar Over past 250 years, Kosi has shifted over 120 km from east to west. The present shift is exactly reverse—to the east

1 comment:

Unknown said...

this is the worst thing that can ever happen 2 ny country. n upon that nepal is not doing nything 2 help us. the state government is really not doing nything 2 help the people. 21 lakh people n only 3 helicopters n a few speed boats. thats not enough.