The Olifants River drains a catchment area of 54,575 square kilometres, making it the biggest river flowing through the Kruger National Park. Although abstraction for irrigation and other uses, as well as changes in the catchment characteristics, have decreased the runoff from the catchment, this river has only twice stopped flowing.
A large proportion of the two-and-half million people living in the Olifants catchment lives in rural third-world conditions, being concentrated mainly in settlements with limited infrastructure. Improvements in their living standards and increased urbanization will have a dramatic impact on the water requirements for domestic use.
There are 30 major dams in the basin. Most of these are used mainly for primary water supply or for irrigation purposes. The decrease in runoff caused by afforestation is limited and restricted primarily to the Blyde River sub-catchment.
Mining activities and power stations are scattered across the basin. The concentration of industrial development, power-stations, rapid urbanisation, irrigation activities, soil erosion mainly due to overgrazing and runoff from rural towns and villages of the Olifants River, all cause serious deterioration in water quality.
Mining and industrial activities at Phalaborwa, just outside the western border of the Kruger National Park (KNP), are also a major source of pollution. Extremely low flows aggravate water quality problems and cause certain aquatic habitats to disappear. High salinity, pollution by heavy metals and high silt loads are the main concerns for conservation and have contributed to the disappearance of at least 5 fish species from the Olifants River (Deacon, 1994).
The high silt loads are generated when sediment-laden releases from the Phalaborwa Barrage are made and have been the cause of massive fish kills downstream in the KNP.
Through the involvement of the Water Quality Management Division of the Department of Water Affairs and Forestry, a system of management rules evolved in the Phalaborwa vicinity to address the water quality problems. These include the re-circulation of seepage water to the source industries, the establishment of purification plants, and the redirection of polluted water from the Selati River (a tributary) into the Phalaborwa Barrage to achieve maximum dilution. In spite of these measures the water is often still so polluted that the KNP has to resort to boreholes for potable water use at Olifants and Satara rest camps.
The problem of water pollution in the Olifants River from the Phalaborwa mines and industries is a crucial one, which is being addressed at several forums at present. Appropriate management actions are continuously identified and implemented to achieve the end goal of rehabilitation of the Olifants River.
It is know locally as the Lepelle and, in Mozambique, Rio dos Elefantes.