Abstract
M.Sc. (Environmental Management)
Surface water quality in the Blesbokspruit Ramsar wetland has been an area of concern since the
1990s, especially following the authorised and subsidised pumping of underground waters—high in
salts—from Grootvlei Mine Shaft No. 3. The pumping was necessary to maintain their underground
mining operations and to avert flooding of low-lying areas from decantation of derelict gold mines
in the Blesbokspruit catchment. High levels of salt, coupled with a change in the flow of the system,
contributed to the loss in the ecological character of the Blesbokspruit wetland in 1996 and, its
subsequent listing on the Montreux Record during the same year. In Ramsar terms, the Blesbokspruit
was under threat and on the brink of losing its international Ramsar status if management action was
not taken to improve the surface water quality of this wetland. The Blesbokspruit has become, since
1996, a wetland in need of restoration to optimum hydrological conditions, i.e. water quality and
quantity. A return to desirable water conditions in the Blesbokspruit wetland would enhance aquatic
species diversity and abundance—especially the important waterfowl species that gave the
Blesbokspruit wetland its international reputation.
With the shutting down of the mine and the cessation of pumping operations at Grootvlei
(Aurora) Mine in December 2010, the surface water in the Blesbokspruit wetland should have
improved and enhanced the agricultural activities (irrigation and livestock watering) adjacent to this
wetland, as well as contributed to healthier aquatic conditions much needed by local and migratory
birds. An investigation of the surface water quality in the Blesbokspruit wetland was performed on
historical water quality data for the period 2000 - 2011, obtained from Rand Water. The study
revealed that there was a distinct seasonal and spatial pattern in the salts (i.e. sulphate, chloride,
sodium, and magnesium), and related electrical conductivity and pH values for sites downstream of
the underground water pumping point at Grootvlei Mine Shaft No. 3. Such observable seasonal and
spatial patterns in the sites downstream of the underground mine-water discharge point could validate
previous findings that had associated saline pollution with the pumping operations of Grootvlei Mine.
Inter-annual trends showed a progressive decline in the concentrations of the salts and associated
electrical conductivity values, with pH readings between neutral and slightly alkaline. Improvements
in the salinity and acidity levels in the Blesbokspruit wetland could then be associated with the
number of water management interventions adopted, particularly by Grootvlei Mine, from the
mid-1990s until December 2010 (the year when mining and pumping operations ceased at Grootvlei
Mine). Nevertheless, during the year 2011, the chemical properties of the Blesbokspruit revealed a
step alteration—a substantial drop in concentrations of sulphate and magnesium salts—following
cessation of underground pumping the preceding year, also confirming previous investigations
linking saline water contamination to underground mine-water pumping operations at Grootvlei
Mine.