South Africa is divided into nine provinces. Each province comprises groupings of magisterial districts. The outer boundaries of the provinces therefore coincide with the outer boundaries of the magisterial districts in the various provinces. Some of these boundaries follow rivers or other geographic features, but the most suitable boundary delineation from an environmental point of view, is the watershed boundary, also known as a catchment boundary. The reason for this is that environmental resources such as water, and control measures such as pollution control, can be more effectively managed within a single catchment.

The current position where provincial boundaries rarely coincide with catchment boundaries means that catchments cannot be managed as complete environmental units situated in a single province. This necessitates effective inter-provincial co-operation in matters relating to water catchment and environmental management. These aspects also need to be co-ordinated at a national level.