An investigation into the spatial and temporal variations in water quality of selected rivers in the Durban Metropolitan Area.

Abstract

The spatial and temporal variations in water quality of selected rivers in the Durban Metropolitan Area were investigated using a Geographical Information System. Dissolved oxygen (DO), turbidity, pH, phosphorus and Escherichia coli (E.coli) were selected as water quality parameters for the study. The study reflects a pattern of water quality deterioration due to the numerous land use practices that have had an adverse impact on the receiving waters. In addition, the communities that use this water for various purposes have been impacted on. Spatially, an impoverishment of water quality conditions were observed by the increase of phosphorus, turbidity, DO and E.coli. The parameter of E.coli represented the worst water quality status in all the catchments of the study area. These were attributable to land use factors such as informal settlements and urban formal settlements. For the parameter of pH, no adverse water quality was present. Temporal evaluation of the data indicated that although there were no distinct trends that could be directly related to rainfall, some of the parameters showed some influence by rainfall, through runoff. Selected rivers of the Durban Metropolitan Area reflect poor water quality. There is an urgent need for the implementation of a strategy for improvement. The evaluation of water quality forms the basis for integrated catchment management (ICM), which has been advocated as the only holistic way to manage water resources. Due cognisance must be taken of the various land use practices, which have a great impact on water quality. There should be concerted efforts to reduce the input of pollutants that may have adverse effects on water quality, e.g., by provisions of sanitation facilities in informal settlements. It is hence recommended that for any improvement of water quality to occur, there needs to be an implementation of ICM for all the catchments.