Master Plans

River System

Brahmaputra Valley

The river Brahmaputra is one of the largest rivers of the world with a specific yield of 85 ha.m./ sq.km., which is next only to Amazon ( 87 ha m./sq.km.). Brahmaputra is the principal arm of the Ganga-Meghna- Brahmaputra system. It originates from Kanglung kang glacier east of Manas–Sarovar at an elevation of 5150 m and traverses 1625 km. in Tibet, 918 km. in India (278 km. in Arunachal Pradesh and 640 km. in Assam) and 363 km. in Bangladesh. The Brahmaputra basin extends over an area of 5,80,000 sq.km., out of which 2,93,000 sq.km. is in Tibet, 2,40,000 sq.km. in India and Bhutan and 47,000 sq.km. in Bangladesh. During its course in the Assam Valley from Kobo to Dhubri, about 26 important tributaries on its north bank and about 13 on south bank join the river. Some of the north bank tributaries originate from snow clad Himalayas and others from the lower Himalayas. The total annual flow of the river is about 573 BCM at Jogighopa Indo-Bangladesh border, which is 29% of the total surface flow of the country. Average width of the Brahmaputra Valley is 80 km, out of which the river itself occupies about 1.5 km to 25 km.

Brahmaputra River

The Brahmaputra River is braided and unstable in its entire reach in the Assam Valley except for a few places. The instability of the river is attributed to high sediment charge, steep slope and transverse gradient. Apart from these, the entire area is in a seismic zone and receives earthquake shocks of moderate to severe intensity from time to time. The problem of siltation has been further aggravated due to landslides caused by high rainfall. Some manmade avoidable actions in the form of shifting cultivation and non-scientific commercial exploitation of forest, etc. have also accelerated the process of soil erosion in the catchments. The silt brought in the process gets deposited as the river descends into the plains with sudden reduction in slope, with the consequent reduction in the flow velocity and its sediment carrying capacity. Due to heavy deposition of silt, the river has frequently changed its course. Excessive silt deposition has also given rise to braiding and meandering pattern in the alignment of the river system. The world’s largest river island “Majuli” in upper Assam lies in the river. The left bank tributaries of the river Brahmaputra pass through stable reaches with flat slopes and carry lower sediment load of finer size. By hypsometric analysis of the tributaries, it is seen that the North bank tributaries indicates relatively young stage while the South bank tributaries indicate a mature stage. This has given rise to inherent tendency of river Brahmaputra to shift its course towards south and the river flows by the slide of hills at many places along its bank.

The flood in Brahmaputra Valley is a recurring phenomenon and has been causing large scale damages every year. The reasons for flood can be summarized as below:

  1. Inadequate capacity of the river channel due to braided nature thereby spilling of floodwater over the banks.
  2. Drainage congestion at the outfall of tributaries during the high stage of the main river, and,
  3. Excessive silt load in the river due to soil erosion and large scale slides in the hilly catchments.

The main crops grown in the Brahmaputra Valley are paddy, jute, mustard, pulses, wheat and sugarcane. Paddy and jute are mainly grown and harvested during monsoon period. Out of four types of paddy crops viz. the Ahu, Sali, Bao and Boro, which constitute about 92% of the cropped area, the first two namely Ahu and Sali are generally affected by floods. The maximum area affected due to floods in the Brahmaputra Valley (including Barak) during the period 1953-2006 was approximately 4.00 M.ha. The flood damage includes crop damage and the permanent loss of land due to erosion. A number of lives are also lost during each flood.

The flood and river management measures adopted so far in the valley are mostly of short term structural measures such as construction of embankments, permeable and impermeable spur, revetment etc. and are area specific only. The poor maintenance of the flood management structures generally causes unexpected miseries to the people in case of their failure. The efficacy of these measures especially in the river system of Brahmaputra, which is highly aggrading/ degrading in different reaches, is also debatable. As such, there is a need for constructing storage reservoirs in combination with other structural/ non-structural measures. The latter can be decided after studying the river behavior using scientific tool.

For management of floods, erosion control and improvement of drainage congestion, the Board has prepared Master Plans for the Brahmaputra main stem and its 39 tributaries and Majuli Island. There is also a need to implement the various recommendations made in the Master Plans of Brahmaputra sub-basin prepared. The regional Task Forces “B” for flood management in N.E. Region has also submitted its report to the Ministry of Water Resources, which should be taken into consideration for early implementation in a time bound manner.

Barak Valley

The river Barak is a part of the Ganga-Brahmaputra Meghna system and is the second largest river of the N.E. Region having eight major tributaries. It originates from a hill east of Mouthana at an elevation of about 2840 m in the southern slopes of Nagaland/Manipur. The Barail, Patkai and Lussai hills bound the sub-basin on its three sides. The total catchment area of the Barak sub-basin up to Indo-Bangladesh border is 41,704 sq.km. Out of which 751 sq.km. lies in Myanmar. The annual flow from Indian catchment is 29,600 m cu m at Badarpurghat. The length of the river from its source upto Bhanga in Cachar district is 532 km. after which the Barak bifurcates into two branches known as the Surma and the Kushiara. These two branches enter Bangladesh and again join to form a single river channel and flow up to Bhairab Bazar where it meets with Meghna in Bangladesh.

The river Barak is joined by a number of hill streams on both its banks. The flood occurs frequently in this valley ausing extensive damage to ives and properties. In order to manage the problem of flood, erosion and drainage congestion, various measures have been taken from time to time by way of construction of embankments, bank protection and drainage improvement works etc. These measures have provided adequate protection to the people of the valley against low and medium floods. In case of high floods, the embankments are not able to withstand heavy pressure, consequently number of breaches occur which cause devastating flood in the valley. In order to deal with the problems of flood, bank erosion, drainage congestion etc., Board has prepared a Master Plan for the Barak sub-basin and Dhaleswari, one of major tributaries of Barak.

Other Rivers

There are eight important rivers in Tripura. These rivers are causing flood frequently in the State. Based on investigation and data collected from the state Govt. and various other Central Agencies, Brahmaputra Board has prepared Master Plan for all these rivers and these have been approved by the Central Govt. The Master Plan envisages various structural and non-structural measures to tackle flood problem, erosion control and recommendable drainage congestion.

Preparation of Master Plans

The Brahmaputra Board had taken up preparation of Master Plans of the main stem of the Brahmaputra and Barak alongwith 55 (including Majuli Island) major tributaries of the region in three parts-

Part River number
part-I Main stem Brahmaputra River (Approved by Government of India) 1
Part-II Master Plan on Barak River and its tributaries except Dhaleswari (Approved by Government of India) 1
Part-III

Master Plan on tributaries of the Brahmaputra and rivers of Tripura including Majuli Island and Dhaleswari

> Approved by Govt. of India - 47

> Approved by Board & submitted to MoWR - 4

> Approved by Board & process for submission - 4

> Completed & in process of circulation - 3

> Identified for Survey & Investigation - 8 Sub Basins

66
Total 68

All 57 Master Plans have been completed by Brahmaputra Board. Out of above, 49 Master Plans have been approved by Government of India and remaining 8 Master Plans are under circulation among Brahmaputra Board Members.

Current Assignment for Preparation of Master Plans

A meeting was convened under the Chairmanship Dr R C Laloo, Hon'ble Minister of Forest and Environment,Government of Meghalaya on 22nd June 2010 in Shillong to discuss the follow up actions on matter related to integrated Water Resources Development in the State of Meghalaya. Shri Vincent Pala, Hon'ble Minister of State, Ministry of Water Resources, Government of India was Chief Guest in the meeting. The Hon'ble Minister of State, Ministry of Water Resources, Government of India desired in the meeting for prepartion of Master Plans of all Rivers of Meghalaya by Brahmaputra Board. Such a decision was communicated was communicated by Ministry of Water Resources to Brahmaputra Board through letter No: 19/2/2010-B&B/3114 dated 28 July 2010. In pursuance to above, a 'Joint Committee' under the Chairmanship of Chief Engineer (P&D) (now Chief Engineer-I), Brahmaputra Board was constituted by Ministry of Water Resources through Office Memorandum No:19/2/2010-B&B/3563-3580 dated 3rd September 2010. The following are rivers of Meghalaya identified for preparation of Master Plans -


Sl.No. Name of River
1. Waikhyrwi
2. Umtrew
3. Ganol
4. Bugi
5. Dareng
6. Umsohryngkew
7. Umiew
8. Myntdu
9. Lubha

As desired by the Ministry of Water Resources in its letter No: 19/2/2010-B&B/3114 dated 28 July 2010, the 'Joint Team' formulated and submitted the 'Inception Report' to the Ministry of Water Resources through letter No: BB/CE(P&D)/MP-7/2010/112 dated 21st February 2011. The joint Committee so far had 7 meetings.

Links for

Current status of Completed Master Plans
Recommendations of Approved Master Plans(North Bank)
Recommendations of Approved Master Plans(South Bank)

Minutes of Meeting convened by Hon'ble Minister of Forest and Environment Meghalaya on 22nd June 2010
Constitution of Joint Team by Ministry of Water Resources for the Preparation of Master Plans of all River Systems of Meghalaya
Inception Report for formulation of Master Plans of Meghalaya
Minutes of Meetings of 'Joint Team' for the preparation of 'Master Plans' of all River Systems of Meghalaya