According to Bihar Disaster Management Authority (BSDMA) about 73.63% of the total geographical area of North Bihar is flood affected. Almost every year North Bihar witnesses flood which damages life, infrastructure as well as crops.
This year also North Bihar witnessed Heavy flood in the region which affected more than70 lakh people and also took life of many. Also Read: Bihar Krishi Roadmap
According to the government data, previous year (in 2019) also, about 12 districts of North Bihar witnessed a very disastrous flood which took the life of 130 people and more than 83 lakh people were affected. The damage to crops were estimated at Rs. 353 Crore and besides those infrastructural damages were in addition.
Flood Prone Areas in Bihar
North Bihar
North Bihar About 16.5% of the total flood prone areas of India is in Bihar and that too mainly in North Bihar.
Some of the most frequent flood affected districts of North Bihar are Darbhanga, Madhubani, Supaul, Saharsa, Madhepura, Khagaria, Muzaffarpur etc.
South Bihar
Although South Bihar have non perennial rivers which are flooded with water only in rainy season and those generally do not cause flooding but near the Southern Bank of Ganga river, south Bihar also witnesses flood in every 2-3 year. Some of the worst flood affected districts of Bihar are Bhojpur, Patna and Nalanda.
- Previous year (2019), almost whole Patna was flooded due to overflow of ganga river.
- Flood causing rivers of south Bihar are Son, Punpun, Harihar and Kiul. But these does not cause large scale flooding and that too for not a very long period.
| Year | Flood Prone Area (in Lakh Hectares) |
|---|---|
| 1954 | 25.00 |
| 1971 | 43.20 |
| 1984 | 64.51 |
| 1994 | 68.00 |
| 2004 | 68.90 |
 |
| Map Credits: BSDMA |
Causes of Floodys in Bihar
The major cause behind flooding in Bihar are rivers coming from Nepal. During Monsoon season, Nepal receives very heavy rainfall which results into increase in water level of these rivers, which generally become overloaded and hence in the basin(in North Bihar) floods occur.
One of the main culprit is the Koshi Barrage on Koshi in Nepal, which has to be opened during overload of water in the river, which brings floods in Supaul and other districts of it's basin.
The rivers which causes the great damages are Koshi, Bagmati, Gandak, Burhi Gandak, Kamla, Balan, Adhwara etc.
Other minor causes are:
- Weak embankment which get broken down by water leads to dangerous flood in the region.
- Already over loaded Ganga river gets even more loaded with water which slow down the speed of rivers in North Bihar, which leads to spread of water in the basin region.
- Another cause is that these river bring alluvium with itself which due to embankment do not dispersed which result into decrease in depth of river hence water carrying capacity of rivers get reduced and flood occurs. (Also Read: Physiographic Divisions of Bihar)
Damages Done by Floods
Direct Damages
- These are evident to us immediately after the flood occurs.
- Damage to life of human and animals.
- Damage to crops and trees.
- Damage to infrastructure like houses, Primary Health Centres, Railway and other transportation and communication facilities and communication lives.
- Foods also damage electricity lines.
Indirect Damages
- Loss im employment of Daily wage workers, artisans and small shop owners.
- Damage to clean drinking water.
- Floods generally followed by epidemic due to various communicable and non-communicable diseases like Malaria, Typhoid, Dengue etc.
- Floods also erode fertile soil and make them lateritic and infertile.
Possible Solutions of Flood Problems
Temporary Solutions
Building Embankment
The first flood Policy of Bihar, 1954 proposed to increase the length of embankment along the flood causing rivers, which was only 160 Km at that time. hence the embankment was increased to 3465 Km but at the same time flood prone area was also increased from 25 lakh hectares to 68.9 lakh hectares by 2004.
- However experts are not in favour of embankment as a permanent solution of flood problem in Bihar because at many instances these embankments get broken due to overload and cause even more disastrous floods in the region. (Also Read: Geological Structure of Bihar)
Cleaning the River Floor
Cleaning the floor of rivers every year before rainy seasons so that the carrying capacity of rivers can be increased.
Permanent Solutions
Building Dams
An Expert Committee formed in 1974 to suggest to control measures on flood control had recommended that a large dam in Barah Region of Nepal, which is the only permanent solution the problem.
- It will not only control flood will also provide Water for irrigation and electricity to both Bihar and Nepal.
Building Link Canals in north Bihar
To control flood this is also an effective solution which has multiple benefits such as for irrigations and increases ground water level hence increases the availability of water for human activities.
- Bihar can make many linking Canals connecting Gandak, Bagmati, Burhi Gandak, Koshi, Mahananda and other rivers at various points especially in upper parts.
Decreasing load of Ganga River
By building canals on Ganga in South Bihar and Uttar Pradesh we can increase the carrying capacity of Ganga by removing the excess water and hence the velocity of flow of rivers in North Bihar will be increased, which will reduce the possibilities of flood.
- Although the possibility of digging canals in South Bihar is quite difficult because south Bihar is elevated. Hence digging a canal out of Ganga towards south is difficult but it can be made possible by building Lift Irrigation Canal like Kaleshwaram Lift Irrigation Project in Telangana. Which will increase irrigation prospects in Drought Prone South Bihar.