Historical population trend, Grahamstown 1840-1980 Thousands people
50 Non-white population 40 30 20 10 White population 0 1840 1860 1880 1900 1920 1940 1960 1980
Source: Maki, H., Mullins, L., Water in Grahamstown, Then and Now – a history of Grahamstown’s water supply from the beginning, 2007, unpublished document.
Figure 7: While the white population were the majority in the early period of Grahamstown, they were outnumbered around 1920. Historically, the non-white population did not pay for water and sanitation services, and this became a problem when this demographic group became the clear majority.
The higher figure matches projections by Maki and Mullins (2007), who estimated the city’s population to reach 125 000 in the ‘’2000s”. The city is estimated to use 3693.2 megalitres of water per year (Makana 2007).
GENERAL WATER SUPPLY CHARACTERISTICS
Grahamstown is located in a dry area, with a mean annual rainfall of 680 mm, and is subject to frequent droughts. The wettest months are February and November, with a dry season lasting from April to September.
The main water source for Grahamstown is the Gariep Dam via the Glen Melville Reservoir, which receives water via an inter-basin transfer from the Orange River. The other water sources are Settler’s Dam, Howison’s Poort Dam, and the smaller Jamieson and Milner dams. Other than Glen Melville, all the dams capture runoff from local streams, all of which cease to flow during most dry seasons.
HISTORICAL DEVELOPMENT OF GRAHAMSTOWN’S WATER SUPPLY The water sources for Grahamstown in the early 1800s were the courses that run into the town from the hills to the south. Small dams diverted the water into furrows and from these each household drew its share according to a timetable (from Maki and Mullins 2007, Hunt 1976). By 1837 the water supply was already inadequate and Maki and Mullins (2007) quote from Hunt (1976) that “Citizens constructed wells in likely places, but the less fortunate had either to beg for a kettle or draw off at the dead of night.” By the 1850s there was an obvious need for water storage to supply the growing population, and following a severe drought in 1858, the council voted funds to build the first municipal reservoir – Grey Dam. Throughout subsequent decades, further and larger dams were built to increase the city’s water supply.
Until the 1990s all the dams were designed to exploit the limited and unreliable supplies from local rivers in the Bloukrans, New Year’s and Kariega catchments. In the 1970s a major inter-basin transfer was constructed from the Gariep Dam on the Orange River, via an 83-km pipeline and canal system into Grassridge Dam on the Great Brak tributary of the Great Fish River. The Great Fish River is naturally seasonal, with flow ceasing in July and August of most years (O’Keeffe and de Moor 1988). The Fish River scheme was originally designed to provide a constant flow of water for year round irrigation in the middle Fish River catchment. With the increasing water shortages of the 1980s, culminating in the worst drought on record in 1991, the Grahamstown Council took advantage of the transferred water by constructing a diversion and storage dam for urban supply. Some of the Orange River water is diverted from the Great Fish via a weir upstream of Fort Brown (Hermanuskraal) through a tunnel into the Glen Melville Dam on the Ecca River, close to the bottom of the Ecca Pass. Two-thirds of Grahamstown’s water demands are met from Glen Melville.