Devastating flood feared from Ganges-Brahmaputra | Greenwatch Dhaka | The leading online daily of Bangladesh

Devastating flood feared from Ganges-Brahmaputra

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Dhaka – Bangladesh braces for even higher, unprecedented floods. The latest satellite imagery of accumulated rainfall by NASA and captured by Indian water expert Himanshu Thakkar shows that Assam Bangladesh, West Bengal and Bihar – already in spate – may face more disastrous floods this month.According to the Flood Forecasting and Warning Centre (FFWC) in Dhaka, the water levels at 77 rivers across Bangladesh marked the sharp rise and 12 stations recorded slight fall yesterday.
Among the 90 monitored river stations, 25 were flowing above the danger level yesterday. Of them, the water of Bhugai river near Sherpur point rose by 236Cm, while the water of Dharla river near Kurigram point rose by 77 Cm, Teesta river near Dalia point by 29Cm, Jamuneshwari near Badarganj point by 132Cm, Jamuna river near Bahadurabad point by 63Cm, Jamuna river near Sirajganj point by 47Cm, Tangan river near Thakurgaon point by 261Cm, Surma river near Kanaighat point by 51Cm and Sunamganj point by 23Cm, Kushiara river near Shela point by 12Cm, Sarigoan river near Sarighat point by 84Cm, Monu river near Monu Railway Bridge by 368Cm, Khoai river near Ballai point by 221Cm and near Habiganj point by 470Cm, Dholai river near Kamalganj point by 278Cm, Bhogai river near Nakoagao point by 320Cm, Someshwari river near Durgapur point by 100Cm and Kangsa river near Jariajangail point by 105Cm.
Water Development Board officials said the water levels of the Brahmaputra-Jamuna, Ganges-Padma and Surma-Kushiyara rivers were in rising trend.
The Brahmaputra-Jamuna and Ganges-Padma rivers are likely to continue rising in next 72 hours, while Surma-Kushiyara rivers are likely to continue rising in next 24 hours.
Water Development Board earlier hinted that a large flood may hit across the country in the mid of the August. The flood water has inundated several parts of around 20 districts in the country.
Himanshu Thakkar wrote, in Assam, India, the satellite imagery shows at least seven flood forecasting sites in orange colour, signifying that at these sites the river water level was within less than half a meter of the Highest Ever Flood level achieved for that site. These included Torsa, Raidak-I, Sankosh, Gaurang, Beki rivers (all northern tributaries of Brahmaputra) and also the Brahmaputra itself at three sites: Neamatighat, Dibrugarh and Tezpur. Closer scrutiny revealed that at many other sites, even though they were shown in pink dot (signifying that river water level is above the danger mark), they were likely to turn orange or red in over the next 24 hours.
In the case of Raidak-I river at Tufanganj site in Cooch Behar district of W Bengal, the water level has already crossed the highest ever flood level for that site and had attained a new level. The river here has already crossed the earlier recorded highest ever flood level of 36.36 m, attained 24 years back on Sept 21, 1993. So the flood here was worst ever in a quarter century, Indian water expert Himanshu Thakkar has written.
Assam State Disaster Management Authority in India said that the Army has been called out to assist the local administration in rescuing marooned people in Nagaon and Kokrajhar districts. “On Assam government’s request, IAF has also put its men on standby, their choppers can be deployed in minimum time for air dropping of relief and rescue operations,” state project coordinator of disaster management Rajib Prakash Baruah said. “We have also deployed additional forces from National Disaster Response Force and State Disaster Response force,” Baruah said.
In the Bangladesh district of Dinajpur Army has been deployed to rescue people at the flood protection has been breached in the district town. In Nilphamari the Teesta Barrage Flood Bypass Road has collapsed under the pressure of flow water from upstream.
The flood salutation in the northern districts of the country has deteriorated further due to heavy downpour and onrush of water from the upstream in the last few days. Several hundred villages, a vast tract of croplands and many establishments have gone under floodwater putting several lakh people in misery.
The movement of motor vehicles has snapped on the Kurigram-Bhurungamari road as three points of the road near Pateshwari area have been washed away by the flood water. Besides, 20 dwelling houses have been damaged by the strong current of the river due to the collapse of an embankment near RDRS bazar area.
In Nilphamari, people of low lying and shoal areas are facing immense suffering for want of safe drinking water as most of the tube-wells have gone under floodwater. The water of Teesta river near Nilphamari point was flowing 65 Cm above the danger level yesterday. – Staff Reporter

Himanshu Thakkar wrote in SANDRP website: In the morning of Aug 11, 2017, while checking my daily morning routine sites, I saw the sudden appearance of a purple patch (signifying rainfall in excess of 175 mm rainfall in previous 24 hours) on NASA daily rainfall accumulation map for the Indian subcontinent.[i]The purpose patch covered parts of the West Bengal, North East Indian and Bangladesh. I was taken aback, but it was not very unusual to see in the peak of monsoon. So as we usually do, I took a screenshot and put up on SANDRP FB page with a warning that this could lead to floods. I did not realize that this was the beginning of an unprecedented wave of floods for these regions that may extend to Ganga basin as I write this. Such purple patches generally disappear in 24 hours, since the rains do not last too long. However, in the case of the current phase, not only the purple patch has last now for 42 hours, it has extended to the west, all along India Nepal region along the southern boundary of Nepal.
By the time I write this, the CWC flood forecasting site[ii]has already shown at least seven flood forecasting sites in orange colour, signifying that at these sites the river water level was within less than half a meter of the Highest Ever Flood level achieved for that site. These included Torsa, Raidak-I, Sankosh, Gaurang, Beki rivers (all northern tributaries of Brahmaputra) and also the Brahmaputra itself at three sites: Neamatighat, Dibrugarh and Tezpur. Closer scrutiny revealed that at many other sites, even though they were shown in pink dot (signifying that river water level is above the danger mark), they were likely to turn orange or red in over the next 24 hours.
In the case of at least one site, namely Raidak-I river at Tufanganj site in Cooch Behar district of W Bengal, the site was already red as I write this, signifying that the river water level has already crossed the HIGHEST EVER FLOOD LEVEL for that site and had attained a new HFL. The river here has already crossed the earlier recorded highest ever flood level of 36.36 m, attained 24 years back on Sept 21, 1993. So the flood here was worst ever, worst in any case in a quarter century.
Assam and parts of W Bengal that had already experienced several waves of floods earlier this monsoon, were thus facing the prospects of even higher, unprecedented floods. Neither the state nor the centre is ready to face this new wave, from all available indications.
In the table below I have given an overview of these sites where the water level has already come within half a meter of highest ever recorded flood levels, of the water level, attained, water level forecast and HFL recorded on CWC’s flood forecasting site.
Ganga Basin to face unprecedented floods next? That the Ganga basin could also face similar unprecedented flood situation in coming days is also apparent from the flood forecast at Basua site in Supaul dist in Bihar along Kosi river (Ganga Basin), already on Aug 12, 2017. The HFL for this site is 49.17 m (reached on Aug 25, 2010). Actual river water level here at 2300 hours on Aug 12 was 49 m, forecast to reach 49.23 m at 0700 hours on Aug 13. This means the river water level here is expected to achieve new HFL on Aug 13 morning already.
Damage in Assam The full dimensions of the impact of this particular wave of flood is not known as yet it will take at least a couple of days to get a clear picture. However, the extent and intensity of the impact is only likely to be greater than the earlier wave. As per the latest available Flood report from Assam Disaster Management Authority[iv], the damage in this round of flood assessed so far is given below. These numbers are so far lower than earlier rounds of floods, but these numbers are likely to go up rapidly in next few days.
• Districts affected: 19 (66 circles, 1752 villages)
• Crop area affected 1 lakh ha
• Population affected 99 lakh
• No of people in relief camps 63800 In 268 camps
• No of people dead 5
• No of houses damaged 56 (fully) + 13 partially
• No of people rescued 2615
This flood wave, when it reaches Bangladesh, along with all the heavy rains in that country, the flood situation in Bangladesh could also worsen in days to come.
Questions about dams and other interventions in North East During the earlier rounds of floods in Assam & rest of North East India, the role of dams, hydropower projects and embankment breaches had come into focus and questions were raised about the efficacy of these structures. Similarly, the govt attempt at dredging the river, creating waterways, building roads cum embankments on both sides of Brahmaputra were also questioned in the context of floods. There is already demand for decommissioning of Ranganadi Hydro in Arunachal Pradesh and Loktak Hydro Project in Manipur, in addition to Dumbur Dam in Tripura earlier and also demand for scrapping of Lower Subansiri Hydro in Arunachal Pradesh Assam border. The role of CWC had also come into sharp focus with questions about how useful its flood forecasting is since many areas where floods occur, there is no flood forecasting by CWC and at other locations, their flood forecasting is too late, erroneous or just not available to right people at right time.
(Himanshu Thakkar is the leader of the South Asia Network on Dams, Rivers and People)

Source: https://sandrp.wordpress.com/2017/08/12/brahmaputra-basin-faces-unprecedented-flood-wave-in-aug-2017/

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