Katse Dam Technical Description
Dam
Double Curvature Concrete Arch
|
Height above foundation
|
185m
|
|
Crest length
|
710m
|
|
Chord length at crest level
|
605m
|
|
Thickness at crest
|
9m
|
|
Thickness at base
|
60m
|
|
Volume of concrete
|
2.32x 106m3
|
|
Cantilever blocks
|
46No. 15m wide
|
|
Lift height
|
2.5m
|
|
Crest elevation(Road)
|
2060masl
|
|
Crest elevation (parapet)
|
2061.55masl
|
Reservoir
|
Total storage capacity
|
1950x 106m3
|
|
Full supply level (fsl)
|
2053masl
|
|
Active storage
|
1519x 106m3
|
|
Reservoir area at fsl
|
35.8km2
|
|
Extreme water level
|
2060.20msl
|
|
Minimum supply level
|
1989msal
|
|
Assumed yield(98% reliability)
|
18.1m3/s
|
Flood Hydrology
|
Status
|
Peak Discharge
|
Volume
|
|
Probable maximum flood (pmf)
|
7874m3/s
|
780Mm3
|
|
1:100yrs return period
|
5000m3/s
|
340Mm3
|
|
1:10yrs
|
1200m3/s
|
87Mm3
|
Spillway
|
Maximum discharge(pmf)
|
6252m3/s
|
|
Maximum head on spillway sill
|
7.20m
|
|
Number of bays
|
10
|
|
Width of bay at crest line
|
15.89m
|
Low Level Outlets
|
Number of Outlets
|
2
|
|
Elevation of outlets
|
1935masl
|
|
Diameter u/s
|
3.8m
|
|
Maximum discharge
|
2x 415m3/s
|
|
2No. Radial control gates
|
3.4 x 2.9m
|
Compensation & Minihydro
|
Number of intakes
|
4 multilevel
|
|
Penstock diameter
|
600mm
|
|
Penstock length
|
150m
|
|
Discharge
|
0.750m3/s
|
|
Minihydro Plant Capacity
|
500kW
|
|
Compensation Pipe Flow
|
0.2 - 0.8m3/s
|
Tailwater Dam
|
Mass gravity overflow weir
|
|
Sill elevation
|
1908masl
|
|
Height of dam above foundation
|
32m
|
|
Number of bays
|
4
|
|
Width of bay
|
14.5m
|
|
Maximum head on sill
|
13.30m
|
|
Maximum discharge
|
6252m3/s
|
|
Volume of concrete
|
79000m3
|
Malibamats'o River
| Catchment area of basin |
1866 km2
|
|
Mean Annual Run-off at the Dam |
554
Mm3
|
|
Estimated annual sediment inflow |
0.6 x 106m3
|
Diversion
Rollcrete gravity dam
|
Maximum height above foundation
|
35m
|
|
Crest elevation
|
1927.3masl
|
|
Spillway section elevation
|
1924masl
|
|
Volume of rollcrete
|
92000m3
|
|
Diversion tunnels
|
2 No
|
|
Diameter lined
|
7m x 7.5m horseshoe
|
|
Length
|
643m and 598m
|
|
Combined discharge capacity
|
1130m3/s
|
|
Bypass gates in tunnel No.2
|
2 No
|
|
Dimensions
|
2.30x 2.00m
|
|
Discharge capacity
|
100m3/s
|
Arch Concrete
|
Required strength
|
24Mpa @90days
|
|
Cemetitious content
|
220kg per m3 with
70:30 OPC:FA
|
|
Max. Aggregate size
|
150mm
|
|
Post cooling
|
90C
|
Construction equipment
|
Tertiary crusher capacity
|
500t/hr
|
|
Batch plant
|
3x 120m3/hr computer controlled tilting mixer
|
|
Cable crane
|
2x 9m3 buckets
Span 1100m
|
|
Target placement rate
|
90000m3/month
|
Contract Details
Contract awarded to Highlands Water Venture (HWV)
|
Joint Venture Partners
|
|
Company
|
Country
|
|
IMPREGILO S.P.A. (SPONSOR)
|
Italy
|
|
BOUYGUES S.A.
|
France
|
|
HOCHTIEF A.G.
|
Germany
|
|
STIRLING INTERNATIONAL LTD
|
United Kingdom
|
|
KIER INTERNATIONAL LTD
|
United Kingdom
|
|
CONCOR HOLDINGS (PTY) LTD
|
South Africa
|
|
GROUP 5 (PTY) LTD
|
South Africa
|
Supervising Engineers: Lesotho Highlands Consultants
|
Joint Venture
|
|
Company
|
Country
|
|
Highlands Water Development Consortium (HWDC) comprising:
|
South Africa
|
|
NINHAM SHAND
|
|
|
WLPU
|
|
|
KEEVE STEYN
|
|
|
MJ MOUNTAIN
|
|
|
SRK
|
|
|
VKE
|
|
|
SCBG comprising:
|
EU
|
|
SOGREAH
|
France
|
|
COYNE & BELLIER
|
France
|
|
SIR ALEXANDER GIBB & PARTNERS
|
United Kingdom
|
Contract Sum M793million = US$306million(1990)
Commencement February 1991
Taking over certificate May 1997
Costs @ completion M1.4 Billion
