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2017 Greater Mekong Forum - Session 34 - Towards more effective river basin management


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Three presentations from Session 34 of the Greater Mekong Forum on Water, Food and Energy, co-hosted by IWRP, the GIZ-MRC Network for Sustainable Hydropower Development in the Mekong countries, the Natural Heritage Institute and Deltares. The Mekong region is undergoing significant change in water resources development for multiple purposes, including hydropower, agriculture, fisheries production and navigation. This also requires the management of the river and its life- and livelihood-giving ecosystems for long term sustainability. Without coordinated development and effective river basin management, the Mekong Basin is exposed to many risks to water resources and associated ecosystems, including floods and drought, deterioration of water quality, reduction of sedimentation loads and extinction of many aquatic species. This session provided an opportunity to recognize these challenges in river basin management and identify development and management needs to tackle these issues.

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2017 Greater Mekong Forum - Session 34 - Towards more effective river basin management

  1. 1. Challenges of water resources management in the Mekong Basin Dao Trong Tu, Ph. D Yangon, October 27, 2017 2017 Great MEKONG Forum on Water, Food and Energy Session 34: Towards more effective river basin management in the Mekong Basin - Challenges and Opportunities
  2. 2. 2 On Mainstream  China: 4 dams built and operated; 5-12 others planned up to 2020  Lao PDR and Thai Lan: 8 -9 being studied and developed  Cambodia: 2 being considered and studied On Tributaries  Hundreds of dams built in all 6 countries mainly for hydropower and irrigation Dam Development on Mekong River
  3. 3. Energy interests vs. other interests • Thailand: Invest to hydropower plants in Lao PDR and import energy and water from Laos for energy demand increasing vs. for rice production. • Cambodia: plan to build 2 large hydropower plants on mainstreams meanwhile vs. maintain huge fishery resources of Great lake. • Vietnam: fully exploited hydropower potential in its Mekong tributaries, investing to some large hydropower plants in Lao PDR and Cambodia for supplementing Vietnam’s energy demand vs. have to protect Mekong delta for food security and livelihood of 17 million people in this area.
  4. 4. Food security • Thailand and Vietnam two first rice exporters in the World (10 million and 5 million respectively in 2009) • Fish production: 2.6 million tones (of 10 million tones worldwide) worth of US$ 2 billion and fish related activities of US$ 5-6 billion a year • Mekong provides food for 60 million people in the basin and 300 million out of the basin
  5. 5. Water governance With this approach (IWRM), the MRC believes a well-balanced, equitable and sustainable development process can be facilitated — for the mutual benefit of all Mekong riparian countries”. (Olivier Cogels – MRC CEO in 2000-2003).
  6. 6. 7 Hydropower Projects in Mainstream of Mekong River
  7. 7. Xayaburi (1,260 MW) Developer: SEAN & Ch. Karnchang Public Co Ltd, Thailand Dam in Lao PDR Reservoir in Lao PDR Extends 150km to Luang Prabang Continuous operation (no peaking)
  8. 8. Don Sahong (240 MW) Developer: Mega First, Malaysia Has PDP Dam in Lao PDR Reservoir in Lao PDR
  9. 9. Don Sahong dam site
  10. 10. Pak Beng (1,230 MW) As shown on the cover of developers feasibility study: Developer: Datang International Power Generation, China • Upper most dam in proposed LMB cascade • Dam in Lao PDR • Reservoir in Lao PDR
  11. 11. Challenges needed to be addressed relating to Water, Food and Energy in Mekong River Basin • Pressure on natural resources of the basin will ever increase. • New challenges and opportunities on development and management the river to achieve their goals in social economic development and livelihood of the people.
  12. 12. • Region: Energy demands and forecasted growth rate of energy sector are expected to be high • China: Full development of Mekong water resources for hydropower • Lao PDR: Revenue from exporting electricity surplus to neighboring countries by building large hydropower on mainstream of Mekong (9- 10 cascades planned to be built in 15-20 years time) Energy-economic expectations
  13. 13. • Thailand: Invest to hydropower plants in Lao PDR and import energy and water from Lao for energy demand increasing and water for rice and other users. • Cambodia: plan to build 2 large hydropower plants on mainstreams meanwhile to maintain huge fishery resources of Great lake. • Vietnam: import for supplementing Vietnam’s energy demand but have to protect Mekong delta for food security and livelihood of 17 million people in this area.
  14. 14. Hydropower dams on mainstream have significant impacts to river ecological conditions of Mekong river basins:  Change flow pattern  Catching the sediment in reservoirs (resources for feeding deltas and nutrient source for fish)  Stop fishery mitigation ways of fish  Big obstacles for inland navigation  Water quality Challenges needed to be addressed relating to Water, Food and Energy in Mekong River Basin (cont.)
  15. 15. Opportunities
  16. 16. Priority Areas of Action “We, the Heads of Government, pronounce that building on the achievements of fifteen years of implementation of the Mekong Agreement, further cooperation over the coming years between the governments of Member Countries will be required to optimize multiple-use of water resources and mutual benefits for all riparians, to avoid any harmful effect that might result from natural occurrences and man-made activities and to protect the immense value of natural ecosystems and ecological balance. Higest Political Commitment – Political will
  17. 17.  Food and human securities of Mekong river basin are visibly posed to big challenges (upstream development, climate change etc.) MRB  Both food and human security and alternatives to mitigate negative impacts on environment, ecology and livelihood of local people in and outside Mekong River basin, avoiding impacts on national, regional and even international food security.  Mekong cooperation should be recognized in a view of common benefits. - Not change natural flood and drought into man-made disasters All impacts should considered and studied before any decision made
  18. 18.  The trade-off issues in water resources development in Lower Mekong between hydropower and food security, human security and other uses should be addressed by highest levels of riparian countries  A regional comprehensive and overall solution for mutual benefits of All countries (win-win solution) in Lower Mekong basin is very essential to avoid any conflict in future.
  19. 19. Future of Food and human securities in Mekong Rive basin ? Thank you for your attention
  20. 20. Sediment management for cascade dams in the context of transboundary rivers Marcel Marchand Yangon, October 27, 2017 2017 Great MEKONG Forum on Water, Food and Energy Session 34: Towards more effective river basin management in the Mekong Basin - Challenges and Opportunities
  21. 21. Why sediment management?
  22. 22. Too little sediment: downstream of reservoirs Reservoirs release clear, sediment- starved water Erosion of the river bed to attain equilibrium concentration of bed material load  erosion downstream of the reservoirs Coarsening of the riverbed The river bed takes decades to centuries to adjust Strong reduction in sediment load observed in many (Asian) rivers: Yellow River (China) Chao Praya (Thailand)
  23. 23. Solutions Restoring the sediment balance in river and coast Many techniques and measures possible, e.g.: Sediment flushing reservoirs Decommissioning (old) reservoirs Stop (illegal) sand mining Sand nourishments / sand motor Sediment bypass Managed realignment / set-back lines Nature based: mangroves, artificial oyster reefs, Etc. River management Coastal management
  24. 24. Mekong Mainstream Dams Key issue: dams in mainstream and tributaries • New dams will have dramatic effects on Mekong Delta according to study (DHI, HDR et al.) • Reduction of sediment and nutrient transport are the largest projected changes, leading to increased coastal erosion of several m/year. Solutions/mitigating measures: • Reduction number of dams • Relocation of dams • Sediment flushing of reservoirs • Etc.
  25. 25. Best practice (1): Reservoir flushing Yellow River (China) Problem: reservoirs trapping sediment, leading to capacity reduction and erosion downstream Solution: Reservoir flushing • Sediment may be released from the reservoir through a bottom gate (not very effective). • Much more sediment is released when combined with drawdown flushing • Regulated (and monitored) release through bottom & mid-depth gates (reservoirs in Europe & Yellow River, China)
  26. 26. Best practice (1): Reservoir flushing Yellow River (China) Implementation • Sanmenxia dam (Yellow River) had to be re-engineered (more bottom outlets) in order to remove sediment. • Flushing in 2002 of Sanmenxia and Xiaolangdi (11 days) moved 362 million tons of sediment to the delta • Since 2003 water and sediment regulation of the Yellow River is carried out every year (Yellow River Conservation Commission prepares plan) Xiaolangdi dam
  27. 27. Best practice (2): Loire (France) Issue: dam construction, flood control, gravel extraction • Arguments for 4 new large dams (up to 100m high) were: flood control, tourism development and water supply for irrigation farming • Arguments against new dams were: loss of natural habitats, blocking of fish (salmon), change in flows and sediment • Many people protested against the plans
  28. 28. Best practice (2): Loire (France) Solutions: 1986: “Loire Vivante” committee (living Loire) Loire Vivante proposed alternatives of how the natural flow of rivers can be conserved while still allowing infrastructural development.  From water supply to water demand management  Early warning for floods  Room for the river  Removal of 2 existing dams that block salmon migration With these alternatives no new dams are needed!
  29. 29. Plan Loire Grandeur Nature Implementation: • With help of WWF, government, EU and local people a vision and new projects were implemented to improve the river ecosystem • “Plan Loire Grandeur Nature”: new basin management model for 20 years. Was first governmental effort to implement a river management strategy for the whole river and over the long term • 1998-2002: Two dams were dismantled and plans for others were cancelled or postponed • Alternatives for flood control were implemented • Adoption of a sustainable river basin approach • Need for long term engagement!
  30. 30. Best Practice (3): Sand nourishment (Netherlands) Problem: coastal erosion Solution: sand nourishment (‘soft measure’)  Artificial deposition of sand from dredging of adjacent offshore area
  31. 31. Sand nourishment programme (NL) Implementation: • After careful scientific studies and monitoring, the Dutch government decided in 1990 to maintain the coastline position and not allow structural retreat anymore and that the main measure would be through sand nourishment. • Nourishments have a typical lifetime of 4 to 5 years • The government budget for coastal care in 2009 amounted to €65 million • Every year up to 12 million cubic metres of sand is used (for about 300 km coastline)
  32. 32. Sand nourishment policy (NL) Success factors: • Government policy – The coastline will be maintained at its position in the year 1990 • Good governance – Clear responsibilities for who is doing what (at national and local level) • Sufficient (scientific) knowledge – Understanding of the sediment dynamics – Good monitoring system (every year the coastal profile is measured) – Design procedure for when how much sand is needed • Financially affordable – Enough sand available at close distance – Dredging equipment available
  33. 33. Planning and implementation requirements
  34. 34. Lessons learned • Sediment balance disturbed by hard measures (dams, breakwaters etc.) • Can only be restored by soft measures (e.g. sand nourishment, reservoir flushing) • This needs long term commitment by stakeholders and government: Long term vision and government policy Annual plans with annual budget Good governance (responsibilities who does what) Monitoring and knowledge enhancement • Even without a fully integrated river or coastal program these measures can be implemented
  35. 35. Sustainable Hydropower Development Alternatives for the Mekong: Maintaining the Flows that Nourish Life Boy in basin navigates through floating village in Tonle Sap, Cambodia. Photo: Sitha Som, Conservation International . Mekong River in Laos. Photo: Andi Mezger Yangon, 27 October 2017
  36. 36. Why focus on fish?
  37. 37. Mekong Fisheries Lower Mekong 1-1.3 million tonnes US$ 1,400 million Middle Mekong 0.9-1.2 million tonnes US$970 million Upper Mekong 60,000 tonnes US$37 million Source: MRC 2007
  38. 38. Lower Se San II Hydropower Project Located at the confluence of two of the largest tributaries that pour into the Mekong mainstream just above the Tonle Sap Lake and Delta
  39. 39. Sambor hydropower project in the Lower Mekong Basin
  40. 40. Sambor Reach of Mekong River  Migratory corridor that experiences the largest movement of biomass on the planet every year  Fish move from Delta and Tonle Sap into Cambodian floodplains, 3-S basin and through Khone Falls  Value of fishery to Cambodia: $1.4 billion/year 15
  41. 41. Environmental Performance Criteria • Fisheries – Fish Survival: 95% at Sambor – Fish Passage • Up- and Downstream – Larval Drift • Downstream Passage • Through Reservoir • Flow Velocity > 0.3m/s – Minimize Barotrauma Potential • Power House • Spillway – Minimize Turbine Mortality • Blade Strike • Shear • Sediment – Pass ~95% of Suspended Sediment • Nutrients – Sustain Fisheries • Mekong Delta – Agriculture & Food Security – Maintain Reservoir Storage • Design Dam to remove deposited Bed Load – No Significant Deposition in Deep Pools • Relocation – Minimize the Number of People to be relocated – Use 100-year Flood as Criterion – No Additional Flooding of Stung Treng
  42. 42. Sambor Dam Comparison – Original Design v. NHI Alternative 7A
  43. 43. Lower Se San 2 Hydropower Reservoir 400MW 1970 GWh/yr 75 km2 reservoir 18 Adding Solar Power to Existing Hydro
  44. 44.  Design a “No-Dam” alternative comparable or superior to Sambor dam for:  Power Reliability  Cost of Power Generation  Power Output  Timeline for Deployment  Financial Risk Avoidance Objective: 19
  45. 45. Mekong River. Photo by WWF Greater Mekong . Internal Review Draft Sustainable Hydropower MASTER PLAN for the Xe Kong Basin in Lao PDR
  46. 46. Lao PDR Policy on Sustainable Hydropower Development 12 January 2015 P. 4: Ensure that potential negative impacts on the environment and social system are prevented or mitigated. P. 6: Project developers shall prevent and mitigate any potential risks to the natural resources and the environment in the design, construction and operation stages. (¶4) :Before the project can be approved, must ensure that negative impacts on the environment can be prevented or mitigated
  47. 47. PRIMARY CONSIDERATIONS FOR SUSTAINABLE HYDROPOWER • Dams fragment the river creating barriers to fish migration and inundate riverine spawning habitats • Dams alter but do not deplete water flows — remove seasonal variability and floodplain interactions • Dams alter and deplete sediment and nutrient flows
  48. 48. Counteract impacts→→ Aspects of project ↓↓↓ Barrier to migratory fish & Innundation of habitat Trapping of sediments and nutrients Alteration of natural flows Siting 1. Above existing barriers to migration Avoid inundation of critical habitat for endemic native species 2. Deeper canyons in headwaters 3. Re-regulation of altered flows for hydropeaking at or below terminal dam Design 4. Fish pass facilities, low-impact turbines, fish screens 5. Low level or radial gates for discharge 6. Low capacity factors of power-plant to accommodate variable discharges; Pumped storage Operation 7. Maintain minimum velocities through reservoirs to maintain larval drift 8. Flushing, sluicing, density current discharges 9. Run of River operations
  49. 49. Xekong 5 Xekong 4B Xekong 3up Xekong 3down Xekong 4A Xekong 2 Xekong 1
  50. 50. Strategy? 1. Siting future hydropower dams in locations that do not inundate or block fish passage into the habitats for migratory species 2. Designing the dams to efficiently pass sediments and nutrients; 3. Operating the dams to maintain a semblance of the natural flow patterns
  51. 51. Four Tiers of Sustainable Replacement Dams
  52. 52. Master Plan for the Xe Kong Basin: Maintaining the Flows that Nourish Life • Water • Fish • Sediment • Nutrients • Information