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

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 182 mill.m3/a

Polihali Yield Analysis Phase 1 Dams Yield 780 106 m3/annum 24.7 m3/s Polihali Contribution to System Yield (of LHWP) 465 106 m3/annum 14.75 m3/s Total LHWP Phase1 and Phase 2 Yield 1271 106 m3/annum 40.3 m3/s - but also need yield replacement dam for Orange River

Main Embankment Main dam Maximum height 163.5 m Essential Excavation Dam fill volume 12 311 210 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