JG Afrika and GWC Consulting Engineers supervised the geotechnical investigations for the Polihali Dam and the Polihali-Katse tunnel, both components of the second phase of the Lesotho Highlands Water Project.
They entailed extracting rock and soil for testing purposes, while identifying the suitability, quality and quantity of construction materials.
There were a number of challenges, particularly in winter when access and communications to the site were cut off due to heavy snowfalls.
An army helicopter also had to be used to transport drilling equipment from one side of Senqu River to the other during the Polihali Dam footprint investigation, while rope access provided coverage over the steep cliff faces during the seismic surveys.