Upstream-Downstream Interaction in the context of shared water regime of NE India: Arunachal, Assam

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1 Upstream-Downstream Interaction in the context of shared water regime of NE India: Arunachal, Assam Partha J Das Water, Climate & Hazard Division Aaranyak-Guwahati Forum for Policy Dialogue on Water Conflicts in India- Pune

2 Brahmaputra-Meghna Basin(China, Bhutan, India, Bangladesh) Source: ICIMOD

3 Shared river regime Siang, Dibang, Lohit, Subansiri, Jia Dhal, Singora, Ranganadi, Dikrong, Buroi, Borgang, Jia Bharali, Burhidihing, Noa- Dihing

4 RIVER SYSTEM OF THE BRAHMAPUTRA & BARAK RIVER BASIN

5 Upstream-Downstream Interaction: A gravity driven natural mechanism for distribution of matter and energy fluxes depending on topography, morphology, weather-climate and natural ecosystems Activities and interventions on the upstream of a river and its catchment always has an impact on the downstream of the river as well as its catchment

6 Upstream-Downstream Interaction Everybody lives in downstream Upstream-Downstream issues cover intrastate/intra-country and inter-state/international(trans-national) domains In the AP-Assam axis, DOWNSTREAM(DS) is not only Assam but also a large part of AP Collaboration and cooperation between US-DS areas is a must for equitable sharing of benefits of water resources

7 US-DS Interaction in NE India GLOF and LDOF Flash floods generated in Trans-Himalayas affecting AP and Assam(Yiggiong LDOF Floods, 200 June) Flash floods in Garo hills created havoc in Assam in 2004 and 2014 LDOF in Bhutan in Sattischu river created flood havoc in Western Assam in 2004 River avulsion of Dibang pushed Lohit southward and changed the land-water dynamics of the Dibru-Saikhowa landscape in Assam

8 Water level variation at Dibrugarh ( ) YEAR EFFECT OF 1950 EARTHQUAKE ON RIVER REGIME, Source: Goswami and Das, 2002

9 Landslide Damming of Brahmaputra (Tsangpo) Tributary in Tibet, June, 2000

10 LDOF: Tibet-Arunachal Border, June 2000

11 Landslide dam induced flooding-2004 A landslide-induced lake on the Tsatichhu river, about 35 kilometres from the Kurichu Hydropower Project, breached at about 4.20 pm on Saturday, July 10, As a result the Kurichu dam released water to the river that flooded Beki-Manas rivers. As a result catastrophic floods gripped Western Assam in 2004 causing unprecedented loss in lives and property

12 Potentially Dangerous Glacial Lakes in Bhutan

13 Flash flood due to heavy rainfall episode, cloud burst, LDOF, GLOF and river dam Flash Flood Havoc at Goalpara, October 7-12, 2004

14 Goalpara flash flood- September 22-23, 2014

15 Video Showing flood Devastation of River Gai on 15 th August, 2011

16 The Maguri-Motapung Beel Complex, Tinsukia District, Assam

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18 Morphological changes in Maguri- Motapung beel Avulsion of Dibang river in early 1980s Southward shift of Lohit river Incursion of the Dibru River into the MMB The beel has become both lotic and lentic in nature The original water body called Maguri beel has almost vanished mainly due to siltation(recorded up to feet) while on the south bank it is expanding mainly due to incursion of the Lohit waters. Bank erosion has become acute in the southern part threatening several villages

19 The Yarlung Zangbo Grand Canyon Chinese intervention on the Brahmaputra: A common concern

20 Implications of US-DS interaction Sedimentation of river beds and bank and flood/flash floods in Assam is determined to a great extent on processes that generate in upstream hills in AP Agriculturally valuable top soil is getting transported from AP to Assam but getting converted to silt and sand Boulder mining in the foothills cause more soil erosion from stream banks and erratic sedimentation in rivers

21 Floods have become erratic, more devastating and more frequent in last two decades More flash flood now accompanied with debris in tributaries of the Brhamaputra

22 Disaster of Sandcasting

23 Structural Adaptation Adaptation Earthen embankment River Drupang, Lakhimpur Geo-bags for bank protection from erosion at Jiadhal(Kumatiya), Dhemaji Geo-tube embankment on the Brahmaputra at Matmora

24 7.76% of the country s total geographical area 24.6%of the country s forest area

25 Dams & DS Impacts Diurnal fluctuation of flow due to peaking power operation of dams Tunneling of rivers Environmental flow Erratic sedimentation patterns on bed and banks: uncertain mode of bank erosion Flash floods due to flow release Displacement due to flood and erosion Internal Migration and outmigration Encroachment, illegal occupation of land Conflict over land

26 Ranganadi HEP at Yazali, AP

27 DSI: RHEP Drastic reduction in lean season flow (December- February) at least by 89% Lowering of GW table, drying of drinking water sources Drying of agricultural land, drought like situations Extinction of fishes, Loss of aquatic biodiversity Loss of livelihood by fishermen community Outmigration of young men and women Internal migration of families/communities Flash floods due to flow release from dam Dolphins no longer seen in the Ranganadi

28 Downstream of Ranganadi going dry at Yazali, AP

29 Downstream condition of the Ranganadi flood plain

30 Flash flood in Ranganadi downstream areas : Karatipara This bamboo bridge is damaged by floods and constructed several times a year

31 Hawa Camp in Lower Subansiri District, AP: Affected by Ranganadi Floods

32 Collapse of the Ranganadi bridge on NH-52 in the 2009 floods

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34 Way Forward Integrated River basin management approach Watershed conservation and management Inter-state collaboration and cooperation in river basin management Collaboration between communities of Upstream & Downstream State policy on interstate rivers Integrated Flood and Erosion Management policy for states River Basin Bill of GoI under consideration Early information about river, water, flood(flood forecasting & flood early warning) Maintain E-flows

35 Need of AP-Assam Cooperation We need to develop more understanding about each other Enhance knowledge about upstream-downstream interaction in shared river basins Collaboration and cooperation in research, advocacy and intervention e.g. mitigation of flood, flash flood, erosion Set up a mechanism for Arunachal Assam Dialogue at regular intervals Take forward the dialogue to a full fledged joint action plan for promoting environmental sustainability in the long-run