Floods in Bihar

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Yearly flood deaths from 1979 to 2019

Year	Humans	Other animals
2020	--	--
2021	--	--
2019	1885	755
2018	1476	643
2017	1521	792
2016	1254	5383
2013	1201	140
2008	2534	845
2007	1287	126
2006	36	31
2005	58	4
2004	885	3272
2003	251	108
2002	489	1450
2001	231	565
2000	336	2568
1999	243	136
1998	381	187
1997	163	151
1996	222	171
1995	291	3742
1994	91	35
1993	105	420
1992	4
1991	56	84
1990	36	76
1989	26
1988	52	29
1987	1401	5302
1986	134	511
1985	83	20
1984	143	90
1983	36	21
1982	25	14
1981	18	11
1980	67	42
1979	14	50

Bihar is India's most flood-prone state, with 76% population in the North Bihar living under the recurring threat of flood devastation.^[1][2] Bihar makes up 16.5% of India's flood affected area and 22.1% of India's flood affected population.^[3] About 73.06% of Bihar's geographical area, ie 68,800 square kilometres (26,600 sq mi) out of 94,160 square kilometres (36,360 sq mi), is flood affected. On an annual basis, they destroy thousands of human lives apart from livestock and assets worth millions.^[4][2] In total, they have claimed 9,500 lives since the government started publishing figures in 1979.^[5] North Bihar districts are vulnerable to at least five major flood-causing rivers during monsoon – Mahananda River, Koshi River, Bagmati River , Burhi Gandak River and Gandak – which originate in Nepal. Some south Bihar districts have also become vulnerable to floods from Son, Punpun and Phalgu rivers.^[6] The 2013 flood affected over 5.9 million people in 3,768 villages in 20 districts of the state.^[7] 2017 flood affected 19 districts of North Bihar killing 514 people.^{[8][9][10][11][12][13][14]} and affecting 1.71 crore people.^{[15][16][17][18]}

History[]

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Reason for flooding[]

Geographically Nepal is a mountainous region. When heavy rains occur in the mountains of central and eastern Nepal the water flows into the major drainages of Narayani, Bagmati, and Koshi rivers. As these rivers cross into India they flow into the plains and lowlands of Bihar and break their banks. To protect the Koshi River dam as well as the Koshi Barrage Pool's embankments, Indian engineers who are in charge of the dam in Nepal, further open the dam's gates which can cause flooding down river in Bihar. In 2008 during a high flow episode a breach in the East Koshi afflux embankment above the dam occurred and the Koshi river, known as the Sorrow of Bihar, picked up an old channel it had abandoned over 100 years previously near the border with Nepal and India. Approximately 2.7 million people were affected as the river broke its embankment at Kusaha in Nepal, submerging several districts of Nepal and India. 95% of the Koshi's total flowed through the new course.

Mitigation[]

Kosi River floods in Bihar can be fully tamed by constructing a 150 km long contour canal starting from Kosi barrage to the Ganga river along the dividing line between Kosi and Mahananda River basins to divert probable maximum flood (PMF). Also Gandak River flooding in India can be fully tamed by constructing a 150 km long contour canal along dividing line between Gandak and the Ghaghra river basins from the right bank of Gandak barrage pond to the Ghaghra river to divert the PMF. Contour canal proposals are viable as it has multipurpose benefits like enhanced irrigation facilities, hydro power generation, navigation, etc.^{[citation needed]}

Embankments[]

A recent fact finding report for the Kosi floods of 2008, prepared by a civil society organization by various experts like Dr. Sudhir Sharma, Dr. Dinesh Kumar Mishra, and Dr Gopal Krishna, highlighted that although India has built over 3000 km of embankments in Bihar over the last few decades, the flooding propensity has increased by 2.5 times during the same time period, not to mention that embankments failed during each major flooding event.

The Fact Finding Mission recently released a report titled Kosi Deluge: The Worst is Still to Come, in which it stressed that embankments straitjacket the river. In the case of the Kosi, it found that because of siltation the river bed was in fact several feet higher than the adjoining land. The high and low lands separated by embankments have created a situation where the low lands have become permanently waterlogged. Sixteen per cent of the land mass of north Bihar is subject to permanent water logging.

In 1954, when the Bihar flood policy was first introduced, Bihar had approximately 160 km of embankments. At this time, the flood-prone area in the state was estimated to be 2.5 million hectares. Upon the completion of the system of embankments, 3,465 km of embankments had been constructed and were administered by the Water Resources Department (WRD). However, the amount of flood-prone land increased to 6.89 million hectares by 2004.

Deforestation[]

Deforestation in the catchment area has led to increase in the silt content of the river flow. The total catchment area of the Kosi is excluding the catchment areas of its two important tributaries, the Kamla and the Bagmati . These tributaries of the Kosi are important in themselves and are generally dealt with separately. Out of the total catchment of the Kosi, only are located in India and the rest lie in Nepal and Tibet. The river's catchment area at Triveni in Nepal is . The average rainfall in the upper catchment of the Kosi is while in the lower areas it is 1,323 mm. The average annual silt load of the river is 92,400 acre-feet (114,000,000 m³).

Farakka Barrage[]

The period has caused serious interception in the dynamic equilibrium of the river hindering the natural oscillation of the river within its meandering belt. The meandering belt of Ganges in Malda and Murshidabad is 10 km wide. The water level of the Ganges rose about 8 m upstream of the Farakka barrage. The river which flowed in a South Easterly course between Rajmahal and Farakka during early decades of this century has now formed a mighty meander loop concentration to accommodate the additional discharge accumulated due to the barrage. Due to the obstruction caused by the Barrage each year nearly 640 million tonnes of silt is accumulated in the riverbed.^[19] In the last three decades this has resulted in the accumulation of nearly 18.56 billion tonnes of silt.

Farakka barrage has led to following problems upstream of the barrage:

• Interception of the flow channel/ changed from straight to oblique
• Sedimentation (640 x106 metric tonnes/ year)
• Reduction of the cross-sectional area
• Declining slope of the long profile
• Widening of the river and increasing length
• Increase in flood frequency and magnitude

A Central Water Commission (CWC) report on Bihar floods in 2016 said that Farakka Barrage, even in the worst scenario can impact areas only up to about 42 km upstream, due to back water effect.^[20] Patna is located about 400 km on the Ganga's upstream. The report blamed heavy banana plantation on the river bank between Patna and Bhagalpur as one of the reasons for the floods, based on the assessment of 100 years of floods in the Ganga. CWC report stated that the sedimentation in Ganga in Bihar is basically due to huge sediment load contributed from its northern tributaries- Ghaghra, Gandak and Kosi. The flood affected area in Bihar was 25 lakh hectares in 1954 when the length of all embankments in Bihar was 160 km, but the flood affected area increased to 72.95 lakh hectares in 2016 with the construction of 3731 km of embankments.^[21]

Affected rivers[]

North Bihar is a play field of eight major rivers. All these rivers end up in Ganges.

• Ghaghra
• Gandak
• Budhi Gandak
• Bagmati
• Kamala
• Kosi
• Mahananda

Statistics[]

Total Affected and Damaged in Bihar due to flood 1979–2006^[22][23]

Year	District	Blocks	Panchayat	Village	Human (in 100,000)	Animal (in 100,000)	Total Area (in 100,000 ha)	Cropped area (in 100,000 ha)	Crop Damaged (in 100,000 INR)	House Affected	Public Property Damaged (in 100,000 INR)
2006	14	63	375	959	10.89	0.1	1.81	0.87	706.63	18,637	8,456.17
2005	12	81	562	1,464	21.04	5.35	4.6	1.35	1,164.50	5,538	305
2004	20	211	2,788	9,346	212.99	86.86	27	13.99	52,205.64	929,773	103,049.60
2003	24	172	1,496	5,077	76.02	11.96	15.08	6.1	6,266.13	45,262	1,035.16
2002	25	6	2,504	8,318	160.18	52.51	19.69	9.4	51,149.61	419,014	40,892.19
2001	22	194	1,992	6,405	90.91	11.7	11.95	6.5	26,721.79	222,074	18,353.78
2000	33	213	2,327	12,351	90.18	8.09	8.05	4.43	8,303.70	343,091	3,780.66
1999	24	150	1,604	5,057	65.66	13.58	8.45	3.04	24,203.88	91,813	5,409.99
1998	28	260	2,739	8,347	134.7	30.93	25.12	12.84	36,696.68	199,611	9,284.04
1997	26	169	1,902	7,043	69.65	10.11	14.71	6.55	5,737.66	174,379	2,038.09
1996	29	195	2,049	6,417	67.33	6.6	11.89	7.34	7,169.29	116,194	1,035.70
1995	26	177	1,901	8,233	66.29	8.15	9.26	4.24	19,514.32	297,765	2,183.57
1994	21	112	1,045	2,755	40.12	15.03	6.32	3.5	5,616.33	33,876	151.66
1993	18	124	1,263	3,422	53.52	6.68	15.64	11.35	13,950.17	219,826	3,040.86
1992	8	19	170	414	5.56	0.75	0.76	0.25	58.09	1,281	0.75
1991	24	137	1,336	4,096	48.23	5.13	9.8	4.05	2,361.03	27,324	139.93
1990	24	162	1,259	4,178	39.57	2.7	8.73	3.21	1,818.88	11,009	182.27
1989	16	74	652	1,821	18.79	0.35	4.71	1.65	704.88	7,746	83.7
1988	23	181	1,616	5,687	62.34	0.21	10.52	3.95	4,986.32	14,759	150.64
1987	30	382	6,112	24,518	286.62	33.25	47.5	25.7	67,881.00	1,704,999	680.86
1986	23	189	1,828	6,509	75.8	XXXX	19.18	7.97	10,513.51	136,774	3,201.99
1985	20	162	1,245	5,315	53.09	XXXX	7.94	4.38	3,129.52	103,279	204.64
1984	23	239	3,209	11,154	135	XXXX	30.5	15.87	18,543.85	310,405	2,717.72
1983	22	138	1,224	4,060	42.41	XXXX	18.13	5.78	2,629.25	38,679	258.14
1982	15	110	1,112	3,708	46.81	45.14	9.32	3.23	9,700.00	68,242	955.33
1981	21	201	2,138	7,367	69.47	74.83	12.61	7.71	7,213.19	75,776	XXXX
1980	21	193	1,869	7,010	74.45	XXXX	17.86	9.43	7,608.43	118,507	XXXX
1979	13	110	XXXX	XXXX	37.38	XXXX	8.06	2.74	1,901.52	27,816	XXXX

See also[]

• 1987 Bihar flood
• 2004 Bihar flood
• 2007 Bihar flood
• 2008 Indian floods
• 2013 North India floods
• 2013 Bihar flood
• 2017 Bihar flood

Gallery[]

• 

  An old picture of 1935 flood in flood

• 

  A view of 2008 Bihar flood

• 

  NDRF in 2008 Bihar flood

• 

  The Kosi before it flooded in August 2008

• 

  The Kosi during the August 2008 flood

References[]

External links[]

• CNN-IBN 30 Minutes documenetary on Bihar Floods 2008 by Marya Shakil - Part 1 Part 2 Part 3 Part 4
• Rapid Response providing relief support to the affected people since 2016.