The Seven Dams Conservancy and the associated areas lies to the north of Bloemfontein and is situated between the N1 National Highway in the west, including the Bloemfontein Botanical Garden, the farm formerly known as Lilyvale 2131, the hills to the north included on the farm ‘The Kloof’ 2921 and Bayswater 2868 adjacent to Eeufees road which passes North Ridge Mall.
Geology & Soils
The geology of the Seven Dams area is relatively simple. It is composed of dolerite dykes and exposures of sheet rock sills, which cap the underlying sedimentary rocks of the Adelaide Subgroup (Beaufort Group, Karoo Supergroup). These dolerite intrusions, both dykes and sills were laid down in their molten state during Jurassic times, some 65 million years ago. The soils are generally shallow (1 – 5 cm on the rock sheets, average of 30 cm, and exceptionally deep 90 – 120 cm in the riverbed at the Bloemfontein Botanical Garden (Müller 1970, Mucina & Rutherford 2006). A layer of red sand of aeolian origin overlays the dolerite sheet rock with shallow, dry gravelly soils on the grassy plains, while deeper clayed soils occur in the bottomlands of streams and wetlands.
Climate & Moisture Availability
Bloemfontein has a hot, wet summer and dry, cold winter. Precipitation is between 457-mm (Gh 5 Bloemfontein Dry Grassland) to 566-mm (Gh 8 Bloemfontein Karroid Shrubland), with mean monthly temperature varying from a minimum of – 2°C to a maximum of 30°C.
Climate change and the predicted reduction in precipitation and increased global temperature will all have a profound impact on the Free State, Bloemfontein and the Seven Dams area in particular. This is all problematic for the Mangaung Municipality and the planned housing developments, which will impose ever-increasing demands on the fresh drinking water supply.