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Lao Mekong Sanakham Hydropower ProjectFeasibility Study Report
Lao Mekong Sanakham Hydropower ProjectFeasibility Study Report
Contents
1.Overview2.Hydology & Sediment3.FSL select4.Installed capacit5.Reservoir inundation 6.Project layout
1.Overview2.Hydology & Sediment3.FSL select4.Installed capacit5.Reservoir inundation 6.Project layout
1
OverviewOverview
OverviewOverview
The Sanakham Hydropower
Project is the 5th cascade project
planned on the main stream of the
Mekong River in Laos. The proposed
dam site is approximately 1737km
away from the Mekong River estuary
in river channel distance, around
155km from Vientiane, the capital of
the country .
The Sanakham Hydropower
Project is the 5th cascade project
planned on the main stream of the
Mekong River in Laos. The proposed
dam site is approximately 1737km
away from the Mekong River estuary
in river channel distance, around
155km from Vientiane, the capital of
the country .
VientianeVientiane
SANAKHAM
155km
Pak LayPak Lay
81km
1772
250
230
192
SANAKHAM
Longitudinal section for cascade development of the Lower Mekong River Longitudinal section for cascade development of the Lower Mekong River
Luang Prabang
Pa Mong
Pak Beng
Sayaburi Pak Lay
Sambor
Don Sahong
Stung Treng
Ban KoumSANAKHAM
For 10 cascade hydroelectric
stations on the main stream, Pak
Beng, Luang Prabang, Sayaburi,
Pak Lay and Sanakham are
located in Laos, Pa Mong and
Ban Koum are situated in the
reach on Laos-Thailand border,
Don Sahong on the border
between Laos and Cambodia,
and Stung Treng and Sambor in
Cambodia.
In July 2009, CNR completed Optimization Study of
Mekong Mainstream Hydropower
the location of Sanakham dam site is moved downstream
from 1772km to 1737km, 2km away from the Thailand-Laos
border.
In August 2009, GOL made it clear that “the maximumoperating level of Sanakham Hydropower Project on theMekong River in Laos is 220m MSL. ”
In July 2009, CNR completed Optimization Study of
Mekong Mainstream Hydropower
the location of Sanakham dam site is moved downstream
from 1772km to 1737km, 2km away from the Thailand-Laos
border.
In August 2009, GOL made it clear that “the maximumoperating level of Sanakham Hydropower Project on theMekong River in Laos is 220m MSL. ”
On December 27, 2010, Overseas Investment Company of DTP
signed the Project Development Agreement (PDA) with GOL.
On December 27, 2010, Overseas Investment Company of DTP
signed the Project Development Agreement (PDA) with GOL.
In June, 2010, Hydrochina Xibei Engineering Corporation completed the
feasibility study in accordance with GOL’s requirement. In July 2010, GOL
reviewed the feasibility study report in line with the WB’s criteria. On August
9, 2010, Electricity Department under Ministry of Energy and Mines, Laos
issued their review comments on the feasibility study.
u
In June, 2010, Hydrochina Xibei Engineering Corporation completed the
feasibility study in accordance with GOL’s requirement. In July 2010, GOL
reviewed the feasibility study report in line with the WB’s criteria. On August
9, 2010, Electricity Department under Ministry of Energy and Mines, Laos
issued their review comments on the feasibility study.
u
Hydrology & Sediment Hydrology & Sediment
Luang Prabang station and Vientiane station are selected
as the design basis for hydrology design of Sanakham Project.
Methodology is the same as that in last version of FS report
Annual mean flow is 4550 m3/s at Sanakham dam site
(CLOSE TO the data of last version)
Item Jun. Jul. Aug. Sep. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May year
Average annual flow (m3 / s) 3,519 7,132 12,131 11,222 6,771 3,970 2,428 1,740 1,380 1,180 1,190 1,690 4,550
Percentage in annual water flow (%)
6.36 13.3 22.6 20.3 12.6 7.17 4.53 3.25 2.33 2.2 2.15 3.16 100%
Hydrology & SedimentHydrology & Sediment
Flood Standard and Characteristic DischargeFlood Standard and Characteristic Discharge
Dam type Work condition
Return
period
(year)
Flood discharge
(m3/s)
Gravity
dam
Design flood 500 31700
Check flood 2000 34400
Energy dissipation and
scour prevention facilities 50 25000
Check flood Standard CHANGED TO 10000 year at last version
The design flood result for Sanakham Hydropower Project
The design flood result for Sanakham Hydropower Project
Design stage ItemDesign values of various frequencies Xp(%)
0.01 0.02 0.05 0.1 0.2 0.333 0.5
Feasibility study Qm 37300 36100 34400 33100 31700 30800 29900
Pre-feasibility study Qm 37300 36100 34400 33100 31700 30800 29900
Planning (MRC1994) Qm 33900
Optimization report
Qm
38800 37000 34700 3300029000
(MRC-CNR2009 )
(36150~41400)
(34550~39450)
(32500~36800)
(30900~34900)
Design stage ItemDesign values of various frequencies Xp(%)
1 2 3.33 5 10 20 33.3 50
Feasibility study Qm 28400 25000 23900 22900 21300 19400 17800 16300
Pre-feasibility study Qm 28400 25000 23900 22900 21300 19400 17800 16300
Planning (MRC1994) Qm 28800 23600
Optimization report Qm 27200 25500 23000 21100 19000 16200
The design value result of average flow in December, January and February during river closure period
The design value result of average flow in December, January and February during river closure period
MonthDesign values of various frequencies Xp(%)
p=10% p=20%
December
First ten-day period 3890 3400
Middle ten-day period 3040 2840
Last ten-day period 2610 2440
January
First ten-day period 2380 2150
Middle ten-day period 2100 1940
Last ten-day period 1890 1790
February
First ten-day period 1720 1610
Middle ten-day period 1620 1520
Last ten-day period 1560 1480
The staged design flood result The staged design flood result
Stage Period (month.day)Design values of various frequencies Xp(%)
5 10 20
Jan. January 1 - January 31 2900 2620 2380
Feb.~Apr. February 1 - April 30 2060 1980 1840
May May 1 - May 31 5260 4200 3360
Jun. June 1 - June 25 9200 8240 6770
Jul. ~Sep. June 26 - October 5 23000 21000 19500
Oct. October 6 - November 5 15100 13500 12200
Nov. November 6 - November 30 9750 8410 6830
Dec. December 1 - December 31 5120 4650 3870
the average sediment concentration in main flood season is
0.686kg/m3, and annual average sediment concentration is
0.495kg/m3.
In the design at this stage, the bed load discharge at the
dam site is estimated by 2% of bed-suspension ratio, and the
average annual bed load discharge is 1.31 million tons.
the average sediment concentration in main flood season is
0.686kg/m3, and annual average sediment concentration is
0.495kg/m3.
In the design at this stage, the bed load discharge at the
dam site is estimated by 2% of bed-suspension ratio, and the
average annual bed load discharge is 1.31 million tons.
FSL SelectFSL Select
It is defined in Optimization Study of Cascade Hydropower
Projects on the Mekong Mainstream in Laos completed by CNR
in July 1, 2009 and file (No. 807 / DOE) “Maximum operating
water level of 5 cascade hydropower project on mainstream of
the Mekong in Laos” issued by Ministry of Energy and Mining
of Laos that the maximum operating level of the Sanakham
hydropower project shall be 220m.
It is defined in Optimization Study of Cascade Hydropower
Projects on the Mekong Mainstream in Laos completed by CNR
in July 1, 2009 and file (No. 807 / DOE) “Maximum operating
water level of 5 cascade hydropower project on mainstream of
the Mekong in Laos” issued by Ministry of Energy and Mining
of Laos that the maximum operating level of the Sanakham
hydropower project shall be 220m.
FSL SelectFSL Select
Installed capacitInstalled capacit
Installed capacitInstalled capacit
Four schemes with installed capacity of 540MW, 600MW,
660MW and 720MW are compared, and 660MW scheme is
considered as optimal.
Four schemes with installed capacity of 540MW, 600MW,
660MW and 720MW are compared, and 660MW scheme is
considered as optimal.
List of Hydro-Energy Parameter for Each Installed Capacity SchemeList of Hydro-Energy Parameter for Each Installed Capacity SchemeItem Unit Scheme 1 Scheme 2 Scheme 3 Scheme 4
Installed capacity MW 540 600 660 720
Normal storage level m 220 220 220 220
Max. head m 20 20 20 20
Min. head m 4.0 4.0 4.0 4.0
Mean head m 15.80 15.80 15.80 15.80
Weighted mean head m 14.51 14.51 14.51 14.51
Mean head in flood season m 12.35 12.35 12.35 12.35
Weighted mean head in flood season m 11.85 11.85 11.85 11.85
Rated head m 13.5 13.5 13.5 13.5
Available discharge m3/s 4500 5000 5500 6000
Annual energy output 108 kWꞏh 34.136 35.666 36.967 38.055
Of which: flood season (June ~ Nov.) 108 kWꞏh 20.001 21.499 22.785 23.865
Dry season (Dec. ~ May ) 108 kWꞏh 14.135 14.167 14.182 14.190
Utilization hours h 6321 5944 5601 5285
Water flow utilization ratio % 71.66 75.20 78.37 81.23
Reservoir Inundation Reservoir Inundation
THE SKETCH MAP OF RESSETTLEMENT PROCESS FOR SANAKHAM HPPTHE SKETCH MAP OF RESSETTLEMENT PROCESS FOR SANAKHAM HPP
The resettlement progress will be compatible with the project construction. The best time for moving people will be in the dry season in year 4 and 5.
Project Layout Project Layout
Comparison of dam siteComparison of dam site
upper and lower
dam are selected for
comparison. the
distance between the
two dam sites is about
3.1km. Lower dam site
is better
upper and lower
dam are selected for
comparison. the
distance between the
two dam sites is about
3.1km. Lower dam site
is better
Technical economy comparison of upper and lower dam sitesTechnical economy comparison of upper and lower dam sites
Item Upper dam site Lower dam site Conclusion
Geology and topography
Rock at right bank is highly weathered with strong load relief, river valley is narrow, riverbed is
covered with shallow silty sand
River valley has open and vast terrain, riverbed is covered with deep silty sand
Two sites can satisfy dam construction requirement
Project layout
River course is smooth and straight, favorable to sand sluicing, it is narrower compared with the lower dam site, left bank will be further excavated to create slope, pre-excavation of ship lock will be difficult
River course turns, measures shall be taken to intercept and sluice sand, left bank has wide terrace, favorable to pre-excavation of ship lock, project layout will be flexible
Lower dam site has smaller risk, and higher safety margin
Reservoir inundation B. Pak La village will not be inundated B. Pak La village will be affected during construction Upper dam site is better
Construction condition
River diversion works will be greater compared with the lower dam site, the existing riverbed is narrow where flow velocity will be high, silty sand at 1st stage whole year cofferdam footprint and its foundation will be severely eroded, cofferdam protection works will be huge
Topography is relative gentle, construction layout is relative simple, river course at the lower dam site is wider, during 1st stage river diversion, the existing riverbed is wider, river flow velocity is relatively low, silty sand at 1st stage whole year cofferdam footprint and its foundation will be less eroded, cofferdam protection works will be small
Lower dam site has better construction condition as artificial aggregate site is close, 1st stage cofferdam can be constructed during dry season
Installed capacity 648MW 660MW
Hydro energy Utilized water head will be 0.28 m lower than the lower dam site, electricity output will be 3.6271 billion kw.h
Electricity output will be 3.6967 billion kw.h
Lower dam site will produce 70 million kw.h more electricity output
Conclusion Lower dam site is better
Selection of dam axisSelection of dam axis
upper and lower dam
sites axis are selected for
comparison. distance
between the two axis is
280m. And Upper dam
axis is suitable .
upper and lower dam
sites axis are selected for
comparison. distance
between the two axis is
280m. And Upper dam
axis is suitable .
Technical economy comparison of upper and lower dam axisTechnical economy comparison of upper and lower dam axis
Item Upper dam axis Low dam axis Conclusion
Topography and geology
Riverbed overburden is 15m in maximum depth, lowest
elevation of bedrock top is 170m
Riverbed overburden is 31m in maximum depth,
lowest elevation of bedrock top is 165m
Upper dam axis is better
Project layout Small overburden quantity, small concrete quantity
High overburden quantity, high concrete quantity Upper dam axis is better
Construction condition
Caisson works of river diversion will be small
Quantity and height of caisson of river diversion
is larger
Construction of upper dam axis is less difficult
Upper dam axis is suitable
1#~13# flood sluice gate section
1#~12# powerhouse section
14#~18#Flood sluice gate
section
Fish pass
500kVswitchyard
230kVSwitchyard
Project structuresarranged from leftbank to right bankare: left bankconcrete wing dam,ship lock, 13 floodsluice gate section,powerhouse section(including 12 units), 5right bank floodsluice gate section,fish pass, right bankconcrete wing dam,etc. The total lengthof water retainingstructure is 886.2 m,maximum concretedam height is 57.2m;230kV and 500kVswitchyards arearranged atdownstream terracesof the left bank andright bank damabutmentsrespectively.
Project structuresarranged from leftbank to right bankare: left bankconcrete wing dam,ship lock, 13 floodsluice gate section,powerhouse section(including 12 units), 5right bank floodsluice gate section,fish pass, right bankconcrete wing dam,etc. The total lengthof water retainingstructure is 886.2 m,maximum concretedam height is 57.2m;230kV and 500kVswitchyards arearranged atdownstream terracesof the left bank andright bank damabutmentsrespectively.
Selected project layout Selected project layout
Navigation
Flood sluice gate section 1~13#250m
Ship lock36m
Left bank wing dam70m
Powerhouse section (1~12# unit blocks and erection bay)352.2m Flood sluice gate section 14~18#
98m Right bank wing dam 80m
886.2m
Upstream and downstream views of selected scheme Upstream and downstream views of selected scheme
230.5▼
230.5▼
▼168.3
▼232.70
56m 43.7m 43.7m 43.7m 43.7m 43.7m 43.7m
Main erection bay
Auxiliary erection bay
▼187.4
Sluice outlet
Powerhouse system consists ofmachine hall, main and auxiliaryerection bays, service building,approach channel, tailrace,switchyard, etc. Unit block length(following river direction) is 80.7m,unit installation elevation is 187.4m,foundation elevation is 168.3m; onesluice outlet will be arranged atmiddle pier between two units ( atotal of 6 sluice outlets) in order toprevent silt deposition before powerintake.
Powerhouse system consists ofmachine hall, main and auxiliaryerection bays, service building,approach channel, tailrace,switchyard, etc. Unit block length(following river direction) is 80.7m,unit installation elevation is 187.4m,foundation elevation is 168.3m; onesluice outlet will be arranged atmiddle pier between two units ( atotal of 6 sluice outlets) in order toprevent silt deposition before powerintake.
Fish pass
Fish pass inlet is set ondownstream floodplain atright bank of the project,outlet is set upstream of wdam at right dam abutment. Fpass is of diaphragm paconsisting of inlets (lower ininvert elevation 198m,uppinlet invert elevation 201.3mfish pass pond, rest pool, out(invert elevation 217m), floretaining gate, bulkhead gate, eWidth of fish pass pond is 5design water depth is 3longitudinal slope ratio i=1/design stage difference 0.0857m
Fish pass inlet is set ondownstream floodplain atright bank of the project,outlet is set upstream of wdam at right dam abutment. Fpass is of diaphragm paconsisting of inlets (lower ininvert elevation 198m,uppinlet invert elevation 201.3mfish pass pond, rest pool, out(invert elevation 217m), floretaining gate, bulkhead gate, eWidth of fish pass pond is 5design water depth is 3longitudinal slope ratio i=1/design stage difference 0.0857m
Fish PassFish Pass
Navigation
U/S cofferdam
U/S longitudinal guide wall D/S longitudinal guide
wall
D/S cofferdam
1st stage rainy-season river diversion1st stage rainy-season river diversionThe 1st stage
river diversion
structure involves the
1st stage starter
cofferdam, 1st stage
upstream and downstream
all-year-round
cofferdams,
longitudinal concrete
guide wall (including
open caisson). The
upstream and downstream
all-year-round
cofferdams are
constructed to retain
water; river flows
through narrowed
riverbed and original
riverbed is used for
navigation.
The 1st stage
river diversion
structure involves the
1st stage starter
cofferdam, 1st stage
upstream and downstream
all-year-round
cofferdams,
longitudinal concrete
guide wall (including
open caisson). The
upstream and downstream
all-year-round
cofferdams are
constructed to retain
water; river flows
through narrowed
riverbed and original
riverbed is used for
navigation.
2ns stage D/S cofferdam
2nd stage U/S
cofferdam
2nd stage river diversion plan layout2nd stage river diversion plan layout
The 2nd
stage river
diversion
involves the 2nd
stage upstream
and downstream
all-year-round
cofferdams and
longitudinal
guide wall,
left-bank 13
sluice gates for
water releasing
as well as
permanent
shiplock for
navigation.
The 2nd
stage river
diversion
involves the 2nd
stage upstream
and downstream
all-year-round
cofferdams and
longitudinal
guide wall,
left-bank 13
sluice gates for
water releasing
as well as
permanent
shiplock for
navigation.
THANKS! THANKS!