The impact of pollution on the water quality of Lake Mzingazi : Richards Bay

M.A.Lake Mzingazi in Richards Bay, is one of the largest freshwater lakes located within a municipal boundary and is the only water source utilised to provide potable water for industries and residents. In addition, it supports rich and diverse fauna and flora communities. Dense swamp and dune forests, marshes and grasslands surround the lake and provide shelter for a wide variety of fauna, which include a number of Red Data Book species such as Python sebae and Crocodylus niloticus. Furthermore, the lake is unique as it is mainly fed from an aquifer. At present, the water quality is good with high oxygen and low nutrient and algae concentrations. However, development since the commissioning of the deep water port of Richards Bay in 1976 has already led to temporary algae blooms since 1979. It is feared that even greater impacts on water quality may result from increasing development in the vicinity of the lake. Presently situated in close proximity to the lake and its feeder streams are formal and informal residential developments. Large industries, pine and eucalyptus plantations and Richards Bay Minerals, a titanium mine, are also situated in the catchment area of the lake. Problems currently being experienced, which could be associated with development, include polluted surface run-off from residential areas that could pollute groundwater, streams and subsequently the lake itself, fringing vegetation is being eradicated, which presently act as a nutrient and pollution filter system, alien plant infestation and atmospheric fall-out from nearby heavy industries contribute to nutrient loading of lake water. The water quality of Lake Mzingazi is therefore under threat should sound managerial practises not be implemented to safeguard the area surrounding the lake and its water quality