Civil Engineering June 2022 | Vol 30 No 5

48 June 2022 Civil Engineering T his article provides an introductory precis to the story of the Orange River Project, currently being finalised in a quality publication, itself the outcome of more than two years of research and data gathering by SAICE’s History and Heritage Panel – several of whose members were employed in the early parts of their respective careers on elements of the project. The project’s multi-faceted objectives, which arose from a century of irriga- tion experience, intense parliamentary lobbying, and decades of increasingly detailed engineering investigation, embraced the irrigation of available arable land, urban water supply, industrial water supply, limited hydro-electric power de- velopment and flood control for the entire region, comprising the Northern and Eastern Cape and southern Free State. BRIEF HISTORY Although seemingly a primarily political decision in the 1960s, South Africa’s Orange River Development Project arose in response to decades (some might say at least a century) of experience with the fickle rainfall and drought succession that has cursed our country since the incep- tion of documented records. In the words of William Willcocks, the eminent British engineer engaged by the post Anglo-Boer War (1899 to 1902) Cape Colonial government to report on opportunities for economic development through irrigation, “West of the great Drakensberg range [the country] is an arid, or semi-arid region. The reason is not so much that rainfall is deficient, but that it comes at the wrong time. What is wanted is water storage, with irrigation works to spread the water upon the land when it is needed by the farmer. Nothing short of an agency of state will serve to bring about this physical revolution.” Willcocks had previously been ap- pointed as part of the team to design and monitor the construction of the Aswan Dam on the Nile River, so came with well-established credentials as regards Africa, its development potential, and its climatic constraints. The outcome of Willcocks’ brief overview of the country’s potential was enormous. Irrigation departments were set up, which were consolidated after Union in 1910, leading to an age of dam building. This following extensive surveys of the country and designs implemented under a succession of eminent directors of irrigation, including W.B. Gordon, F.A. Kanthack and A.D. Lewis. Lewis in particular realised that no significant development could take place along the Orange River without major storage works to service arable land sited in neighbouring catchments, including those of the Great Fish River of the Eastern Cape and neighbouring tributaries of the Orange River. Consequently, arable land on which decades of small-scale agricultural ventures had alternately prospered and failed through the 1800s began to reap the benefits of a more sustained irrigation potential. However, the fickleness of the drought and rainfall cycle remained, and a sustainable irrigation supply remained an illusion. Furthermore, many of these dams suffered the consequences of siltation, as had private farm dams in the previous century, due to erosion of the precious but fragile soil cover so characteristic of inland South Africa. However, like Willcocks and his vision for the Orange River with its key storage potential, the contribution by Lewis to the development of the country’s water re- sources was enormous; but he was ahead of his time in regard to the country’s capability for implementing the schemes on the scale he envisaged. It remained a project for future generations. PRELIMINARY STUDIES As the primary dam building agency, the Department of Water Affairs (DWA) – the successors to the Irrigation Department following World War II – was moving ahead with dam building on an increasing scale, together with behind-the-scenes investigations towards ultimately imple- menting the Orange River Project. The site of Vanderkloof Dam, within a prominent gorge through highly competent dolerite rock, had been clearly identified during the early surveys preceding Union in 1910. The alignment of the diversion tunnel – to be known as the Orange-Fish Tunnel – was largely determined by the shortest distance H i story and her i tage 1960s & 1970s Orange River Development Project Alastair Morgan Pr Eng, FSAICE SAICE History & Heritage Panel Member alastair@geoid.co.za This year marks the 50 th anniversary of the commissioning of the first element of the Orange River Project – the Gariep Dam – situated near Colesberg in the Northern Cape. For a mega-project of inter-basin water transfer that was formally presented to the South African Parliament in a 1962 White Paper, and finally given the go-ahead a year later, this outcome represented a remarkable civil engineering achievement of global proportions.