3rd Mekong Forum on Water, Food & Energy 2013. Presentation from Session 9: Managing the impacts of dams across cascades.

1. CPWF
MK17
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
3rd
Water 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: 30/12/2013
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
CPWF
MK17

3. CPWF
MK17
COLLABORATION
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

4. CPWF
MK17
SREPOK 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 Activities
Agriculture
Perennial plants
Fishery
Tourism
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
CPWF
MK17

6. CPWF
MK17
ISSUES: DROUGHT
Aridity Index
1.20
1.00
Aridity Index
Dry season lasts from January to
August in Krong Ana, from
December to June in Krong Kno
and January to June in Srepok
Mainstream.
Buôn Ma Thuột
Buôn Hồ
0.80
0.60
0.40
0.20
0.00
I
II
III
IV
V
VI
VII VIII
IX
X
XI
XII
Month
Station
Giang Sơn
Đức Xuyên
Bridge no.14
Bản Đôn
River
Krông Ana
Krông Knô
Srepok
Srepok
Minimum 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-05
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

7. CPWF
MK17
ISSUES: FLOOD
 Flooding in Krong Ana: Oct, Nov (70%)
 Flooding in Krong Kno: Sep, Oct (73%).
 Most serious flooding in Lak-Buon Trap
•
Historical floods
o Krong Ana: Qmax=1620 m3/s (22/11/1998)
o Krong Kno: Qmax=4020 m3/s (10/10/2000)
o Dòng chính Srepok: Qmax=3600 m3/s
(12/10/2000)
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

8. CPWF
MK17
RISING ISSUES: Less rainfall
Rainfall decreasing year by year in
dry season
Drought in Krong Buk (2010)
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

9. Th ỜI GIAN
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
2013/6
2012/11
2012/4
2011/9
2011/2
2010/7
2009/12
2009/5
2008/10
2008/3
2007/8
2007/1
2006/6
2005/11
2005/4
2004/9
2004/2
2003/7
2002/12
2002/5
2001/10
2001/3
2000/8
2000/1
1999/6
1998/11
1998/4
1997/9
1997/2
1996/7
1995/12
1995/5
1994/10
1994/3
1993/8
1993/1
ĐỘ CAO TUYỆT ĐỐI MỰC NƯỚC (m)
RISING ISSUES: Groundwater level decreasing
CPWF
MK17
ĐỒ THỊ QUAN TRẮC MỰC NƯỚC TRẠM C8a
EAPHÊ - KRÔNGPACH - ĐĂK LĂK
470.000
469.000
468.000
467.000
466.000
465.000
464.000
463.000

10. CPWF
MK17
RISING ISSUES: Groundwater level decreasing
Pilot study in bazan area in
Buon Ma Thuot – Ea Tul
BIẾN ĐỘNG MỰC NƯỚC NGẦM VỊ TRÍ LK71T NĂM 2005 VÀ 2010
774
LK71T-2005
772
LK71T-2010
770
Mực nước (m)
768
766
764
762
760
758
12/3/2009
1/22/2010
3/13/2010
5/2/2010
6/21/2010
8/10/2010
9/29/2010
11/18/2010
1/7/2011
2/26/2011
Thời gian
BIẾN ĐỘNG MỰC NƯỚC NGẦM VỊ TRÍ LK75T NĂM 2005 VÀ 2010
429
428
Mực nước (m)
427
426
425
LK75T-2005
424
LK75T-2010
423
422
421
420
12/3/2009 1/22/2010 3/13/2010
5/2/2010
6/21/2010
8/10/2010 9/29/2010 11/18/2010 1/7/2011
Thời gian
Groundwater level comparison in 2005 and 2010
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
2/26/2011

11. RISING ISSUES: Flood increasing
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
CPWF
MK17

12. RISING ISSUES: Water pollution
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
CPWF
MK17

13. RISING ISSUES: Environmental flow
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
CPWF
MK17

14. RISING ISSUES: River erosion
Krong 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 QUESTIONS
CPWF
MK17
1) 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 catchment’s environment?
5) In what ways are the Srepok River’s 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 PROPERTIES
River
Area
(km2)
Length
(m)
Elevation
(m)
Srepok
12.133
315
570
Krong Ana
3.960
215
720
- Krong Buk
478
130
590
- Krong Pach
692
74
622
- Krong Bong
809
73
950
Krông No
4620
156
683
Ia Hleo
4760
128
381
Ea Drang
977
78
391
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
CPWF
MK17

17. WATER RESOURCES DISTRIBUTION
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
CPWF
MK17

18. CPWF
MK17
GROUND WATER
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

19. CPWF
MK17
LAND USE
Type of land
Total
Agricultural land
Forestry land
Specialized land
Residential land
Unused land
Area (HA)
1,826,430
452,864
1,048,725
53,922
10,364
257,687
Water 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
MK17
HYDROPOWER
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

22. SURFACE WATER MODELLING: MIKE BASIN
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
CPWF
MK17

23. SURFACE WATER MODELLING: MIKE BASIN
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
CPWF
MK17

24. GROUND WATER MODELING: MIKE SHE
Water availability, use and trends
in the Srepok River Catchment (Vietnam)
CPWF
MK17

25. CPWF
MK17
MIKE SHE: Land use map
2005
2010
2020
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

26. CPWF
MK17
MIKE SHE: Results
Water balance model in MIKE SHE
Total Error
4
Precipitation
18809
Evapotranspiration
11751
Snow -Storage change
0
OL-Storage change
24
Irrigation
642
769
Canopy-Storage change
0
OL->river/MOUSE
2713
Boundary flow
1794
UZ-Storage change
230
Pumping
506
7194
Infilt. incl. Evap
3484
8
Base flow to River
367
Drain to river
2911
SZ-Storage change
-63
Accumulated 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 BMT
2005
2010
2020
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

27. FINDING: CHANGE OF WATER SOURCES
CPWF
MK17
 Hydrological extremes occur more frequently following by
reduction 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 release
in flood seasons leading to alteration of natural flow.
Inappropriate operation could result in severe negative
impacts.
 Water quality is degrading
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

28. FINDING: CHANGE OF WATER REQUIREMENTS
CPWF
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 demand
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

29. FINDING: MANAGEMENT AND EXPLOITATION
CPWF
MK17
 Water resources planning is fragmented – lacking of
integrated water resources planning for the whole river.
 Reduction in forestry area.
 Lacking
of throughout management of reservoir
operation.
 Water
use
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
MK17
RECOMMENDATIONS
 Making integrated water resources planning in the Srepok
river catchments.
 Reforesting and protecting forestry area.
 Complying with agricultural development plan.
 Developing
sustainable agriculture,
irrigation and choosing suitable crops.
applying
micro
 Repairing the old or less effective reservoirs and building
new hydraulic works.
 Improving
management
effectiveness.
between different stake holders.
Negotiating
 Establishing Srepok RBO.
Water availability, use and trends
in the Srepok River Catchment (Vietnam)

32. CPWF
MK17
THANK YOU FOR YOUR ATTENTION!
Water availability, use and trends
in the Srepok River Catchment (Vietnam)