1. CPWF MK17Water availability, use and trends in the Srepok River Catchment (Vietnam)3rdWater availability, use and trends CPWF Forum, Ha Noi 20 Catchment (Vietnam) in the Srepok River November 2013

2. GENERAL INFOMATION Project name: Water availability, use and trends in the Srepok River Catchment (Vietnam)Duration: 10 months Commencing: 1/3/2013 Ending: 30/12/2013Water availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 3. CPWF MK17COLLABORATIONWater availability, use and trends in the Srepok River Catchment (Vietnam) 4. CPWF MK17SREPOK RIVER BASIN Basin area: 29,500 km2 (18.264 km2 in Vietnam) Administrative boundary: 4 provinces of Gia Lai, Dak Nong, Dak Lak and Lam Dong Population: 1.8 million inhabitants. Mean annual precipitation: 1560-2528mm Water availability, use and trends in the Srepok River Catchment (Vietnam) 5. SREPOK RIVER BASIN: Economical ActivitiesAgriculturePerennial plantsFishery Tourism Water availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 6. CPWF MK17ISSUES: DROUGHT Aridity Index1.20 1.00 Aridity IndexDry season lasts from January to August in Krong Ana, from December to June in Krong Kno and January to June in Srepok Mainstream.Bun Ma Thut Bun H0.80 0.600.40 0.20 0.00IIIIIIIVVVIVII VIIIIXXXIXIIMonthStation Giang Sn c Xuyn Bridge no.14 Bn nRiver Krng Ana Krng Kn Srepok SrepokMinimum of monthly Minimum of daily Area catchment Discharge Discharge Time Date 2 (Km ) (m3/s) (m3/s) 3180 4.67 Apr-05 3.40 21-Apr-05 3080 13.8 Apr-05 0.89 28-Dec-09 8670 18.3 Apr-05 13.4 10-Apr-98 10700 27.1 Apr-05 8.24 21-Apr-05Water availability, use and trends in the Srepok River Catchment (Vietnam) 7. CPWF MK17ISSUES: FLOOD Flooding in Krong Ana: Oct, Nov (70%) Flooding in Krong Kno: Sep, Oct (73%). Most serious flooding in Lak-Buon Trap Historical floodso Krong Ana: Qmax=1620 m3/s (22/11/1998) o Krong Kno: Qmax=4020 m3/s (10/10/2000) o Dng chnh Srepok: Qmax=3600 m3/s(12/10/2000) Water availability, use and trends in the Srepok River Catchment (Vietnam) 8. CPWF MK17RISING ISSUES: Less rainfallRainfall decreasing year by year in dry seasonDrought in Krong Buk (2010)Water availability, use and trends in the Srepok River Catchment (Vietnam) 9. Th I GIANWater availability, use and trends in the Srepok River Catchment (Vietnam) 2013/62012/112012/42011/92011/22010/72009/122009/52008/102008/32007/82007/12006/62005/112005/42004/92004/22003/72002/122002/52001/102001/32000/82000/11999/61998/111998/41997/91997/21996/71995/121995/51994/101994/31993/81993/1 CAO TUYT I MC NC (m)RISING ISSUES: Groundwater level decreasing CPWF MK17 TH QUAN TRC MC NC TRM C8a EAPH - KRNGPACH - K LK470.000469.000468.000467.000466.000465.000464.000463.000 10. CPWF MK17RISING ISSUES: Groundwater level decreasing Pilot study in bazan area in Buon Ma Thuot Ea TulBIN NG MC NC NGM V TR LK71T NM 2005 V 2010 774LK71T-2005 772LK71T-2010770Mc nc (m)768 766 764 762 760 758 12/3/20091/22/20103/13/20105/2/20106/21/20108/10/20109/29/201011/18/20101/7/20112/26/2011Thi gianBIN NG MC NC NGM V TR LK75T NM 2005 V 2010 429 428Mc nc (m)427 426 425LK75T-2005424LK75T-2010423 422 421 420 12/3/2009 1/22/2010 3/13/20105/2/20106/21/20108/10/2010 9/29/2010 11/18/2010 1/7/2011Thi gianGroundwater level comparison in 2005 and 2010 Water availability, use and trends in the Srepok River Catchment (Vietnam)2/26/2011 11. RISING ISSUES: Flood increasingWater availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 12. RISING ISSUES: Water pollutionWater availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 13. RISING ISSUES: Environmental flowWater availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 14. RISING ISSUES: River erosionKrong Kno River at downstream of Buon Tua Srah Hydropower plant (photo taken on 5/5/2013)Water availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 15. RESEARCH QUESTIONSCPWF MK171) What is the land use within the Srepok Catchment, and how much water is used by each land use category? 2) How do water use changes in one sector affect water uses in other sectors? 3) How many dams and reservoirs are there in the Srepok Catchment? 4) How much water is needed to sustain the catchments environment? 5) In what ways are the Srepok Rivers flows, and surface water-groundwater interaction, affected by changes in land use within the catchment, and the construction of WSI (both existing and planned)? 6) How does/will these changes affect flows of water and sediment into Cambodia? 7) If current water use trends remain the same, how will water use in the catchment look in the future (2020 and 2050)? 8) What are the various costs and benefits of management interventions both now and in the future?Water availability, use and trends in the Srepok River Catchment (Vietnam) 16. RIVER SYSTEM PROPERTIESRiverArea (km2)Length (m)Elevation (m)Srepok12.133315570Krong Ana3.960215720- Krong Buk478130590- Krong Pach69274622- Krong Bong80973950Krng No4620156683Ia Hleo4760128381Ea Drang97778391Water availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 17. WATER RESOURCES DISTRIBUTIONWater availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 18. CPWF MK17GROUND WATERWater availability, use and trends in the Srepok River Catchment (Vietnam) 19. CPWF MK17LAND USE Type of land Total Agricultural land Forestry land Specialized land Residential land Unused landArea (HA) 1,826,430 452,864 1,048,725 53,922 10,364 257,687Water availability, use and trends in the Srepok River Catchment (Vietnam) 20. IRRIGATION STRUCTURE Four main irrigation subareas Ia Muer- Ea Hleo Krong Ana. Krong No.Srepok.Water availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 21. CPWF MK17HYDROPOWERWater availability, use and trends in the Srepok River Catchment (Vietnam) 22. SURFACE WATER MODELLING: MIKE BASINWater availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 23. SURFACE WATER MODELLING: MIKE BASINWater availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 24. GROUND WATER MODELING: MIKE SHEWater availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 25. CPWF MK17MIKE SHE: Land use map 200520102020Water availability, use and trends in the Srepok River Catchment (Vietnam) 26. CPWF MK17MIKE SHE: Results Water balance model in MIKE SHETotal Error 4Precipitation 18809Evapotranspiration 11751Snow -Storage change 0 OL-Storage change 24Irrigation 642769 Canopy-Storage change 0 OL->river/MOUSE 2713Boundary flow 1794UZ-Storage change 230Pumping 5067194Infilt. incl. Evap 34848Base flow to River 367Drain to river 2911 SZ-Storage change -63Accumulated w aterbalance from 1/1/1995 to 12/24/2005. Data type : Storage depth [millimeter]. Flow Result File : H:MIKESHE_NCKHSrepok_LU2005(95_05)bom2005Srepok_LU2005(95_05)bom2005 Title : Srepok model Text : for groundw ater field northeast BMT200520102020Water availability, use and trends in the Srepok River Catchment (Vietnam) 27. FINDING: CHANGE OF WATER SOURCESCPWF MK17 Hydrological extremes occur more frequently following byreduction in rainfall during dry season and increase in flood season. Drought is more severe in recent years. River erosion, water level is reduced in many places Reduction in groundwater flow in term of volume and WL Hydropower plants store water in dry seasons and releasein flood seasons leading to alteration of natural flow. Inappropriate operation could result in severe negative impacts. Water quality is degradingWater availability, use and trends in the Srepok River Catchment (Vietnam) 28. FINDING: CHANGE OF WATER REQUIREMENTSCPWF MK17 Water requirement from all sectors increased since 2005 until now and in the future. Agriculture production: As planning, total coffee area will be reduced until 2020 and 2030 together with sustainable agricultural practices including constructing a number of reservoirs. However, actual coffee area is now increasing. Industry: Further industrialization increases demand for water. Requirement from hydropower increased from 2005 and is stable in the future. Population increase in the area: Enlarged urban area results in higher demandWater availability, use and trends in the Srepok River Catchment (Vietnam) 29. FINDING: MANAGEMENT AND EXPLOITATIONCPWF MK17 Water resources planning is fragmented lacking ofintegrated water resources planning for the whole river. Reduction in forestry area. Lackingof throughout management of reservoiroperation. Wateruse conflicts between sectors and upstream/downstream and within a single water supply structure Water storage is reduced. Waste in water use. Water availability, use and trends in the Srepok River Catchment (Vietnam) 30. FINDING: MANAGEMENT AND EXPLOITATION Too much ground water was extracted by deep wells, especially with high density in areas of coffee Wells are drilled by the farmer or private group without professional knowledge.Water availability, use and trends in the Srepok River Catchment (Vietnam)CPWF MK17 31. CPWF MK17RECOMMENDATIONS Making integrated water resources planning in the Srepokriver catchments. Reforesting and protecting forestry area. Complying with agricultural development plan. Developingsustainable agriculture, irrigation and choosing suitable crops.applyingmicro Repairing the old or less effective reservoirs and buildingnew hydraulic works. Improvingmanagement effectiveness. between different stake holders.Negotiating Establishing Srepok RBO. Water availability, use and trends in the Srepok River Catchment (Vietnam) 32. CPWF MK17THANK YOU FOR YOUR ATTENTION!Water availability, use and trends in the Srepok River Catchment (Vietnam)