Civil Engineering June 2022 | Vol 30 No 5

Civil Engineering June 2022 49 between appropriate positions (and eleva- tions) on the Orange and upper Great Fish River catchment, beneath the Zuurberg Plateau, and the need for gravity-driven water transfer defined in early designs at a gradient of 1:2000. The site for Gariep Dam, like that of Vanderkloof, needed to be underlain by competent, high strength rock, of which the outcropping dolerite hills, so typical of the Karoo Sequence geology along the Orange River, were many. But it was also dictated by the need to provide an accept- able location for the tunnel intake within the basin of the dam and at an appropriate elevation for optimal diversion of the river flows under “normal” dam operations. The chosen site, on the farm Ruigtevallei, presented an acceptable location for the dam, of lesser height than Vanderkloof but nevertheless favourable from the tunnel intake perspective, and also underlain by a significant dolerite intrusion. The scene was set. In March 1962, in an attempt to stimulate the country’s then faltering economy, the White Paper prepared by DWA initiating the first phase of a proposed six-phase project was presented to Parliament. Parliamentary approval was granted a year later in May 1963 with R85 million (arguably equiva- lent to R8 billion in 2022) allocated for the first stage. INCEPTION OF THE PROJECT It was initially reported in the press that engineering designs and construction bids for this vast project would be sought from international consulting engineers and contractors, probably then very much fol- lowing the model that had been set up for the Kariba Dam scheme on the Zambezi River by our northern neighbours. The response of the South African engineering community, incensed at the prospect of being sidelined for this major scheme, was rapid and at the highest level. A delegation of representatives of the foremost consulting civil engineers and the president of SAICE accordingly met with the Secretary for Water Affairs to put forward the strongest case for including the expertise of well-established local engineering resources. The outcome of this was the rather unusual DWA decision to appoint joint South African and foreign engineering consortia for each key element of the project, obviously then intended to obtain the best possible skills transfer from foreign to local practices and, one imagines, that valid South African inputs to and control over the project details were not lost. Key negotiations followed between leading foreign civil engineering (British and French) firms and the foremost South African practices, many representatives of which had never even met before, let alone worked together as consortia, and respective responsibilities were formalised to best advantage, and which were finally appointed by DWA. By the time the project approval was given in May 1963, the consortia were already established, and the stage was set. Meetings and site visits followed im- mediately to initiate the final designs and contracting formalities. Interesting observations from the past of significant impact to the Orange River Project include the facts that all engineering and designs of the day preceded the advent of computer-based analysis, data processing and project management tools, GIS, GPS, CPM, etc. as we know them today, and the SI system of measurement was only just replacing the British Imperial system. Hence, we observe the liberal use of both systems (feet and metres, cusecs and cumecs, etc.) in historical documents pertaining to the projects. Figure 1 Map showing the extent of the Orange River Development Project The Orange–Fish Transfer Tunnel (from map produced by DRASECOM/ SA Department of Water Affairs)