Project Location
Balangan dam is located on Balangan river in Binuangsantang village, Kecamatan of Tebing Tinggi in Balangan Regency. Geographically, the location of Balangan dam plan lies on 2o26’15” S and 115o42’08” E.
Topographical of Dam Site
Morphologically, Balangan dam is located in surge hills, with the elevation range from + 125 m as the Balangan river bed elevation to + 600 m, in Meratus mountain.
Morphological of Balangan divided into two kind of morphology are hilly area and valley plain area of Balangan river.
Hilly area is on the left dan right Balangan river. The inclane of morphology are between 300 till 500 and elevation between + 125 m till 350 m above sea water level.
Than, wide of valley plain area of Balangan is about 30 m till 100 m with elevation + 125 m above sea water level.
Technical Data of the Dam
1. Main Dam
Alternative 1
Type : Vertical Core Zonal Dam
Flood Design,
Q1000 : 401,98 m3/sec.
QPMF : 954,84 m3/sec.
Dam height : 56 m (of the bed rock)
Crest Length : 325,63 m
Crest width : 11 m
Elevation of River bed : 118 m
Slope Inclination, U/S : 1:2,5
D/S : 1:2,0
Embankment Volume : ± 1.152 million m3
Alternative 2
Type : Vertical Core Zonal Dam
Flood Design,
Q1000 : 401,98 m3/sec.
QPMF : 954,84 m3/sec.
Dam height : 57 m (of the bed rock)
Crest Length : 386,31 m
Crest width : 11 m
Elevation of River bed : 117 m
Slope Inclination, U/S : 1:2,5
D/S : 1:2,0
Embankment Volume : ± 1.471 million m3
Alternative 3
Type : Vertical Core Zonal Dam
Flood Design,
Q1000 : 401,98 m3/sec.
QPMF : 954,84 m3/sec.
Dam height : 56 m (of the bed rock)
Crest Length : 282,00 m
Crest width : 11 m
Elevation of River bed : 118 m
Slope Inclination, U/S : 1:2,5
D/S : 1:2,0
Embankment Volume : ± 1.354 million m3
2. Cofferdam
Alternative 1
Type : Inclined Core Zonal Fills
Design Flood,Q20 : 214,78 m3/sec.
Cofferdam height : 18 m
Crest Elevation : EL.141,00 m
Crest width : 10,00 m
Crest length : 128.79 m
Elevation of River bed : 125 m
Slope, U/S : 1:2,5
D/S : 1:2,0
Embankment volume : 86,778 m3
Alternative 2
Type : Inclined Core Zonal Fills
Design Flood,Q20 : 214,78 m3/sec.
Cofferdam height : 19 m
Crest Elevation : EL.141,00 m
Crest width : 10,00 m
Crest length : 258,29 m
Elevation of River bed : 125 m
Slope, U/S : 1:2,5
D/S : 1:2,0
Embankment volume : 187,658 m3
Alternative 3
Type : Inclined Core Zonal Fills
Design Flood,Q20 : 214,78 m3/sec.
Cofferdam height : 18 m
Crest Elevation : EL.141,00 m
Crest width : 10,00 m
Crest length : 128,00 m
Elevation of River bed : 125 m
Slope, U/S : 1:2,5
D/S : 1:2,0
Embankment volume : 116,158 m3
3. Diversion
Alternative 1
Type : Tunnel Modified Horse Shoe
Length : 260.00 m
Inner Diameter : 3,20 m
Bottom Inlet Elevation : EL. 125.00 m
Bottom Outlet Elev. : EL. 123.00 m
Slope of the Tunnel : 0.008
Design Flood, Q20 : 214,78 m3/sec.
Design Flood, Q25 : 86,95 m3/sec.
Flood Water Level, Q20 : EL.138,60 m
Alternative 2
Type : Tunnel Modified Horse Shoe
Length : 380.00 m
Inner Diameter : 4,40 m
Bottom Inlet Elevation : EL. 130.00 m
Bottom Outlet Elev. : EL. 126.00 m
Slope of the Tunnel : 0.011
Design Flood, Q20 : 214,78 m3/sec.
Design Flood, Q25 : 133,01 m3/sec.
Flood Water Level, Q20 : EL.139,15 m
Alternative 3
Type : Tunnel Modified Horse Shoe
Length : 350.00 m
Inner Diameter : 3,60 m
Bottom Inlet Elevation : EL. 126.00 m
Bottom Outlet Elev. : EL. 125.00 m
Slope of the Tunnel : 0.003
Design Flood, Q20 : 214,78 m3/sec.
Design Flood, Q25 : 101,89 m3/sec.
Flood Water Level, Q20 :EL.139,19 m
4. Inundation Area
Catchments area : 44,00 km2
River length : 16,96 km
River bed elevation : + 125,00 m
Design Flood
Flood Water Level Q1000: EL.171,32 m
Probable Max. Flood
QPMF : 954,84 m3/sec
Water Level of PMF
Q PMF : EL.172,79 m
Gross Storage : 21,34 mil. m3
Effective Storage : 16,28 mil. m3
Dead storage : 2,78 million m3
Inundation Area : 111,39 m2
Annual Rainfall : 1.270,00 mm
5. Spillway
Alternative 1
Type : Chute Overflow
Threshold width : 52 m
Elev. of Threshold : EL. 169,30 m
Transition Channel :
· Channel width U/S : 52,00 m
· Channel width D/S : 20,00 m
· Channel length : 70,00 m
· Slope : 1 : 1000
Chute Channel
· Width : 20,00 m
· Length : 115,74 m
Stilling Basin
· Elevation : + 119,21 m
· Width : 20,00 m
· Length : 16,51 m
Alternative 2
Type : Side Spillway
Threshold width : 52 m
Elev. of Threshold : EL. 169,30 m
Side Channel :
· Channel width U/S : 12,00 m
· Channel width D/S : 16,00 m
· Length : 52,00 m
Transition Channel :
· Width : 16,00 m
· Lenght : 150,00 m
· Slope : 1 : 500
Chute Channel
· Width : 16,00 m
· Length : 153,154 m
Stilling Basin
· Elevation : + 119,40 m
· Width : 16,00 m
· Length : 43,00 m
Alternative 3
Type : Side Spillway
Threshold width : 52 m
Elev. of Threshold : EL. 169,30 m
Side Channel :
· Channel width U/S : 12,00 m
· Channel width D/S : 16,00 m
· Length : 52,00 m
Transition Channel :
· Width : 16,00 m
· Lenght : 90,00 m
· Slope : 1 : 500
Chute Channel
· Width : 16,00 m
· Length : 88,167 m
Stilling Basin
· Elevation : + 120,00 m
· Width : 16,00 m
· Length : 46,00 m
6. Intake Structure
Alternative 1
Type : drop inlet
Equipment
· Trash rack : fixed (vertical)
- Above of shaft : 2,0 m W x 1,0 m H
- Side : 1,0 m W x 1,0 m H
· Pipe intake
- Length of conduit Ø 1,00 m – 118,50 m (1 line)
- Butterfly control valve Ø 1,00 m
· Outlet
- Steel pipe Ø 0,30 m (1 line)
- Butterfly control valve Ø 0,30 m
- Sluice gate 1,20 m L
· Operation house pump
- Pond inlet pipe Ø 0,5 m
- Control valve (sluice gate) Ø 0,5 m
- Control valve (sluice gate) Ø 0,3 m
Alternative 2
Type : drop inlet
Equipment
· Trash rack : fixed (vertical)
- Above of shaft : 2,0 m W x 1,0 m H
- Side : 1,0 m W x 1,0 m H
· Pipe intake
- Length of conduit Ø 1,00 m – 265,00 m (1 line)
- Butterfly control valve Ø 1,00 m
· Outlet
- Steel pipe Ø 0,30 m (1 line)
- Butterfly control valve Ø 0,30 m
- Sluice gate 1,20 m L
· Operation house pump
- Pond inlet pipe Ø 0,5 m
- Control valve (sluice gate) Ø 0,5 m
- Control valve (sluice gate) Ø 0,3 m
Alternative 3
Type : drop inlet
Equipment
· Trash rack : fixed (vertical)
- Above of shaft : 2,0 m W x 1,0 m H
- Side : 1,0 m W x 1,0 m H
· Pipe intake
- Length of conduit Ø 1,00 m – 194,10 m (1 line)
- Butterfly control valve Ø 1,00 m
· Outlet
- Steel pipe Ø 0,30 m (1 line)
- Butterfly control valve Ø 0,30 m
- Sluice gate 1,20 m L
· Operation house pump
- Pond inlet pipe Ø 0,5 m
- Control valve (sluice gate) Ø 0,5 m
- Control valve (sluice gate) Ø 0,3 m