Govt. of WATER RESOURCES DEPTARTMENT

A REVIEW OF FLOOD MANAGEMENT MEASURES AND FUTURE VISION IN ASSAM

Presentation for 3rd NEC SECTORAL SUMMIT

By - Er A. K. Mitra Secretary to the Govt. of Assam Water Resources Department, , Assam

BRAHMAPUTRA BASIN

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BRAHMAPUTRA RIVER BASIN

Brahmaputra river is the 6th largest river in the world in terms of Water Resources (629.05 Km3/year) Drainage area : (Total - 5,80,000 Sq km.) In & Bhutan : 2,40,000 Sq km, Bangladesh : 47,000 Sq km. Length: (Total- 2906 km) India : 918 km, Bangladesh : 363 km , Assam : 640 km

1 RIVER SYSTEM OF

Major tributaries 41 Nos North bank 26 Nos South Bank 15 Nos

RIVER SYSTEM OF

MEGHALAYA KARBIANLONG AND N.C.HILLS DISTRICTS

1 DHOLAI BANDARKHAL

DAMCHARA Jatinga R Larsing CHANDRANATHPUR Madhura R NABANPUR SUROMOR KUMBHIRGRAM BIHARA BORKHOLA AMARA RAJA BAZAR HILLARA NAGAR BadraJOINPUR R Kushiyara R PANJPU LALUGRAM Chiri R LABAK BAZAR BADARPUR Jiri R BHANGA LATU LAKHIPUR BANSKAND Barak R MOHISHASAN KALIGANJ KATHAL T.G. ADAIR KONA ALGAPUR Dhaleswar R NILAM BAZARRATAKANDI MOHANPUR H Ghagra R S E DIDARKUSH D KABUGANJ MATINAGAR R.F A SONBIL L G PATHARIA DWARBAND N BHUBAN A KANAI BAZAR B LOWAR DHALAI MANIAKHAL AMARAGHAT BOND SAPTAGRAM PATHARKANDI ANIPUR BHANGA BAZAR LONGAIHAT LALA CHEERA MOINPURHAT SINGIRHAOR RAHCHAND T.G RHAWEITING MUKAMCHERRA DULLABCHERRA T.G. Rukni Sonai R KATLICHERRA KATAKHAL R.F MANIPUR LOWAIRPOWA

MANIPUR OLIVIA T.G KURIAHERA ISABEEL T.G. T.G Longai R DANCHERRA GHARHURA Singla R 4 TRIPURA 2

RIVER SYSTEM BARAK VALLEY MIZORAM

Major tributaries 20 Nos In India 11 Nos India and Bangaladesh 15 Nos

2 FLOODS AND EROSION

Main causes

‰ Physiographic condition of the valley

‰ Drainage congestion

‰ Geology and Geomorphology

‰ Excessive rainfall

‰ Seismicity and Landslides

‰ Encroachment of Riverine Areas

‰ Other factors

Map showing erosion sites in Brahmaputra and Barak Valley

3 SIGNIFICANT EROSION REACHES OF RIVER BRAHMAPUTRA

Bank Reaches District Area in Ha South Chumoni 400 South Dhola Hatighuli Tinsukia 600 South Rohmaria 298 South Neamati 328 South island Jorhat 42,000 North Kareng Chapori, Arney Chapari, Dhemaji 10,000 Matmara South Moirabari-lahorighat-Bhuragaon Morigaon 15,000 South Hatimura area near Jakhalabandha 186 North Bishwanath-Panpur Sonitpur 350 South Palasbari-Gumi area Kamrup 10,000 South Mukalmua area 80,000 North Bohori-Baghbar area 8,000 South Town, -Hazirghat Goalpara 40,000 including South Salmara Township North -Patamari area Dhubri 2,500

DAMAGES DUE TO FLOODS & EROSION

‰ The state has a total flood prone area of 31.60 Lha

‰ Average area affected in a year 9.31 LHa.

‰ Average total damages in a year Rs 124.28 Crores

Since 1954 Total area eroded = 386,000 Ha. (7%) Rate of erosion = 8,000 Ha./Year No. of villages eroded = 2,534 Families affected = 90,700

Affected Reaches Moderate to Severe 130 Most Severe 25

Oil Installations/Tea Gardens/ Important Towns and Cities/ Heritage Sites 18

4 STRATEGY ADOPTED BY WATER RESOURCES DEPT FOR FLOOD MANAGEMENT

Immediate and short-term measures:

‰ FLOW CONFINEMENT BY EMBANKMENTS ‰ ANTI EROSION MEASURES & RIVER TRAINING WORKS ‰ PRO-SILTATION DEVICES ‰ SLUICES ‰ DRAINAGE DEVELOPMENT WORKS

Long term measures: Creation of reservoir in the upper reaches. Task Force constituted by Govt. of India also equivocally opined for implementation of such multipurpose projects for ensuring flood moderation benefits

Funding pattern of the W R Dept

™ State Plan ™ Central Loan Assistance (CLA) /Central Sector Schemes (CSS)/ Expenditure Finance Committee (EFC) ™ Additional Central Assistance (ACA) ™ Calamity Relief Fund (CRF) / (NCCF) ™ North Eastern Council (NEC) ™ Non-lapsable Central Pool of Resources (NLCPR) ™ Joint River Commission (JRC) ™ Assistance from external agencies (NABARD)

5 TASK FORCE RECOMMENDATION

9 Task force recommendation for taking up Flood Management Measures as short term I and short term II has not been fully operationalised as yet.

9 During 10th Five year Plan (2006-07), only 22 Cr has been sanctioned for 10 numbers of flood management schemes.

9 The state govt strongly desires that recommendations of the Task Force should be implemented during 11th Five year Plan. Accordingly the proposal has been framed and is being submitted to the Brahmaputra Board / Ministry of Water Resources.

Future Perspective and Vision

¾ The short term measures undertaken by the dept has afforded reasonable protection to 16.49 Lakh Hectare flood affected area out of 31.50 Lakh Hectare (about 52%) flood prone area of the state.

¾ It has been realised that the flood and erosion problem of the state cannot be solved unless the long term measures, as suggested by the National Flood Policy (1954) and recommendations of master plan of Brahmaputra and task force are implemented.

¾ Since the long term measures are not coming up very soon, the state need to continue with the feasible short and medium term measures for at least next 15 years.

¾ For this, the department has chalked out a Comprehensive Vision plan considering the developmental prospects and the growth of population in the state.

6 Vision Plan 2020 Rs in lakh Category of Schemes Priority-I Priority-II Total Estimated Cost

STRUCTURAL MEASURES EMDANKMENT (in km) New embankment 94.00 km 100 km 194.00 km 26210.00 Gap closing/retirement 175.00 km --- 175.00 km 7964.00 Re-Strengthening (R/S) 2464.40 --- 2464.40 km 52347.00 km Town Protection works (No) 13 No 51No 64 No 11857.00 Anti- erosion Works (No) 79 No 323 No 402 No 64848.00 Drainage schemes (No/km) 43 No 212 km 43 No, 212 km 17237.00 Sluices (No) 63 No 42 No 105 No 8932.00 Unidentified schemes 1100.00 NON STRUCTURAL MEASURES Raised platform (No) 30 No 304 No 334 No 10353.00 Flood Forecasting & insurance CWC Govt. of India is responsible Flood Plain Zoning, Flood Risk Maps 500.00 Research & Development, 5000.00 Organisational infrastructure, Hydrological Analysis, investigation and planning of new schemes Total 206348.00

Vision Plan 2020 The has already embarked upon an ambitious mega project titled NORTH EASTERN INTEGRATED FLOOD AND RIVERBANK EROSION MITIGATION PROJECT. The salient features of this project are-

Funding Agency: Asian Development Bank (ADB)

Nodal Agency: Ministry of DoNER

Estimated Cost: Rs 1600 crores (in Assam)

Expected investment To be decided by ADB & Govt. of India

Implementing Agencies Govt. of Assam and in their states Status ADB has already sanctioned Project Preparation and Technical Assistance (PPTA) for the part relating to Assam. The PPTA will start from the1st week of April 2007. Accordingly Draft Project Report of four selected projects has been submitted to the ADB

7 Proposed project site at Oakland-to Mohanaghat BRAHMAPUTRA RIVER BASIN area

Proposed project site at Bandana-Matmara-Tekeliphuta area

Proposed project site at Proposed project site at Bonkoal-Mariahola-Difflopathar Palasbari-Gumi and area adjoining area

NORTH-EAST WATER RESOURCES AUTHORITY (NEWRA) 9 The Hon’ble Prime Minister during his visit to Assam on Nov 2004 announced establishing a cohesive, autonomous, self- contained entity called North East Water Resources Authority (NEWRA).

9 The formation of the NEWRA is in advance stage and active consideration of Govt. of India.

9 This Authority will go a long way in proper utilization and harnessing water resources of the entire North Eastern region and will help in speedier implementation of the plans and programmes so envisaged.

9 Hon’ble Prime Minister further reiterated during the conference of Irrigation Ministers’ at New on Nov 2005 the need for the creation of NEWRA for fostering the developmental process in N. E. Region.

8 FLOODS AND EROSION (Causes) Physiographic condition of the valley

Narrow elongated U-shaped valley opening towards the Bay of Bengal branch of approaching Monsoons

AVERAGE WIDTH Valley : 80 to 90 Km, RIVER BRAHMAPUTRA River : 6 to 10 Km

BED SLOPE Int. Border to Kobo: 1 in 2390 Kobo to Dhubri: 1 in 6990

DISCHARGE at Pandu Max: 72,794 cumes (1962) Min: 2,300 cumes (Jan/Feb)

9 FLOODS AND EROSION (Causes) Physiographic condition of the valley

ELEVATION VS DISTANCE OF THE BRAHMAPUTRA RIVER COURSE

FLOODS AND EROSION (Causes) Drainage congestion

‰ High stages of the Brahmaputra river over prolonged periods obstruct free discharge of tributaries causing back flow and congestion near outfalls.

‰ Restricted waterway of road and railway bridges and culverts obstruct the natural flow of water.

‰ Inadequate countryside drainage through sluices in embankment system particularly during high floods causes prolonged inundation in the countryside.

‰ Encroachment of natural drainages further aggravates the situation.

10 FLOODS AND EROSION (Causes) Geology and Geomorphology

‰ Lesser Himalayas comprise of relatively younger rock formations and are in the process of building up. Friable in nature and easily erodible & prone to landslides.

‰ A very young river. Its present configuration took shape only during the Pleistocene and recent times

FLOODS AND EROSION (Causes) Excessive Rainfall

‰ Excessive rainfall concentrated during the monsoon months from May to October

‰ Mean annual rainfall over the catchments area in India is around 2300 mm

‰ Mean annual rainfall varies between 2480 mm in the Brahmaputra valley to 6350 mm in North Eastern Hills.

11 FLOODS AND EROSION (Causes) Seismicity and Landslides

Brahmaputra Valley is subjected to frequent tectonic activity. The valley falls under Zone V, which is highly risk zone.

Some of the recent major earthquakes of this region are: ‰ Great Indian Earthquake-1897 (8.7) ‰ Srimangal Earthquake-1918 (7.6) ‰ Dhubri Earthquake-1930 (7.0) ‰ Assam Earthquake-1950 (8.6) and ‰ Indo-Burma Earthquake-1988 (7.0).

FLOODS AND EROSION (Causes) Seismicity and Landslides

‰ Frequent tectonic activity causes geo morphological changes and landslides.

‰ Excessive sediment charge causes rivers to change course frequently.

‰ Carrying capacity is reduced thereby river either spills its banks or erodes.

‰ Formation of braided channels and constant shifting of channels & sand shoals.

12 FLOODS AND EROSION (Causes) Encroachment of Riverine Areas

‰ Narrowness of the valley and restricted availability of plain areas for habitation.

‰ Increase in population and developmental activities leading to encroachment of chars.

‰ Density of population in plain areas more than 200 persons per sq km.

FLOODS AND EROSION (Causes) Other causes

‰ Deforestation and improper land use due to the practice of shifting or Jhum cultivation in the hill tracts and grazing

‰ Laterals southward shift of the river causing migration of bank line through erosion.

‰ Fanning out effect at Nodal points causing instability & erosion.

‰ Lateral southward shift of the river

‰ Deforestation and improper land use

‰ Fanning out effect at Nodal points

13 LONG TERM (STRUCTURAL) MEASURES

FLOOD MANAGEMENT MEASURES ADOPTED BY WATER RESOURCES DEPT

5000 4448 4458 4465.19 4176 4000 3161 3000

2000

Length in km in Length 1000 211 0 1954 1969 1980 1992 2002 2006

Length of embankment Year

Cumulative length of embankment constructed by the Water Resources Department

14 FLOOD MANAGEMENT MEASURES ADOPTED BY WATER RESOURCES DEPT

18 15.8 16.181 16.49 16 13.98 14 12 10 8 7.16 6

Area in lakh ha in lakh Area 4 2 0 0 1954 1969 1980 1992 2002 2006

Benefited area Year

Area benefited (Cumulative) due to construction of embankments by the Water Resources Department

FLOOD MANAGEMENT MEASURES ADOPTED BY WATER RESOURCES DEPT

1200

1000 846 850.69 856.69 770 772 800

600

400

200 Drainage Channel in km in Channel Drainage 0 0 1954 1969 1980 1992 2002 2006 Length of Drainage channel Year

Cumulative length of Drainage channel constructed by the Water Resources Department

15 FLOOD MANAGEMENT MEASURES ADOPTED BY WATER RESOURCES DEPT

800 681 704 600 533

400 Numbers 200 67 2 29 0 1954 1969 1980 1992 2002 2006 Year No of A/E and Town Protection Works

Cumulative No of A/E, Town Protection works completed by the Water Resources Department

SATELLITE PLAN FORM OF THE BRAHMAPUTRA IN -GUMI REACH 2002

Zoomed View of Saraighat Bridge

A B

Width of Channel at A – 18 Km Width of Channel at B –1.5 Km

16 SCHEMES EXECUTED UNDER NEC

9th FIVE YEAR PLAN (1997-2002)

Sl. No Name of scheme Estimated Fund released by NEC amount (Rs in Lakh) (Rs in Lakh) 1 Controlling of Jiadhal 5403.29 Lakh Project has started in phased manner. Earmarked fund is 145 lakh for 2006-07 2 R/S to Flood protection, 499.74 450.00 Patharkandi-Ph-II Total 5903.03 450.00

SCHEMES EXECUTED UNDER NEC 10th FIVE YEAR PLAN (2002-2007)

Sl. No Name of scheme Estimated Fund released by amount NEC (Rs in (Rs in Lakh) Lakh) 1 Anti-erosion measures of Chunpura Bazar 111.09 109.80 area () 2 A/E to NH-44 at Lowaipowa against 50.87 50.87 erosion of river Longai (Karimganj Dist.) 3 Controlling of Gainadi for protn of Rail & 499.85 499.55 Road communication for Arunachal Pradesh. (Dhemaji Dist.) 4 a) Controlling of Jiadhal river in Dhemaji 1233.00 Subsequently District. Estimated Cost - Rs. 1233.00 Lakh modified and taken to 10th Plan b) Controlling of Jiadhal river in Dhemaji 9.03 8.00 Dist.(Model Study).(Conducted by B. B.) Total 1903.84 668.22

17 9 The genuinely expect and benignly wish that the NEC would play a more active role to reduce the perpetual flood and erosion havoc by extending generous funding mechanism for implementation of short and medium term flood and erosion management schemes

9 The investment in the long run will boost economy of the State of Assam and the benefit will be extended to other North Eastern States as well since Assam is the gateway of North East.

NEC SCHEMES AT A GLANCE 11th Five year Plan Proposals

Sl Name of Scheme Estimated Beneficiary No. cost States 1 Controlling of Jiadhal river 5403.29 Assam, Arunachal Pradesh 2 Survey and investigation of small projects 276.48 All NE states 3 Protection of NH-44 & Srigouri area near Badarpur 1656.60 Assam, Tripura Town 4 R/S to extension of embankment along B/B of Longai 464.29 Assam, Tripura 5 R/S to flood prevention in and around Patharkandi 704.04 Assam, Tripura 6 R/S to extension of embankment along B/B of Longai 1022.04 Assam, Tripura 7 Protection of Naskar and Karicherra bazar area 499.89 Assam 8 Protection of Borbeel Kachari gaon and Muamari area 992.26 Assam 9 R/S and extension of B/B of Gainadi dyke 1448.06 Assam, Arunachal Pradesh 10 Protection of Milanpur No.2 area and Road & Railway 998.80 Assam line 11 Long term measures to check erosion of river 8553.50 Assam, Brahmaputra near Porabhita and South Salmara in . 12 Protection of Simen Chapori Town 1500.00 Assam

18 Severely damaged N.H.-44 at Srigouri area due to erosion & sloughening of river Barak

Severely damaged N.H.-44 at Srigouri area due to erosion & sloughening of river Barak

River Barak

19 Severely damaged N.H.-44 at Srigouri area due to erosion & sloughening of river Barak

N.H.- 44

Severely damaged N.H.-44 at Srigouri area due to erosion & sloughening of river Barak

20