1. LESOTHO HIGHLANDS WATER PROJECT PHASE 2
4/11/2017
LESOTHO HIGHLANDS WATER PROJECT PHASE 2
OVERVIEW
By P D Pyke
October 2012

3. Yield analysis - Polihali
Dam yield ( MOL 1992, FSL 2065) viewed in isolation:
14,75 m3/s 465mil. m3/a
Incremental Orange River system yield
5,76m3/s mill.m3/a

4. Polihali Yield Analysis
Phase 1 Dams Yield
m3/annum
24.7 m3/s
Polihali Contribution to System Yield (of LHWP)
m3/annum
14.75 m3/s
Total LHWP Phase1 and Phase 2 Yield
m3/annum
40.3 m3/s - but also need yield replacement dam for Orange River

5. Main Embankment Main dam Maximum height 163.5 m Essential Excavation
Dam fill volume m3
U/s and d/s slope
u/s 1: 1.4
d/s 1:1.25, average 1:1.4
Crest width / length
10 / 915 m
Reservoir Volume
2 322 million m3
Surface area
50.4 km2