Preliminary guideline for the determination of buffer zones for rivers, wetlands and estuaries.

South Africa’s aquatic ecosystems are under increasing pressure, with impacts such as regulation of flow by impoundments, pollution, over-extraction of water, and the breakdown of natural bio-geographical barriers all affecting the ecological condition of these resources. The need for preventative measures to avoid further degradation of these resources has therefore been highlighted. It is in this context that establishment of buffer zones to rivers, estuaries and wetlands can play a meaningful role in reducing impacts to aquatic resources and in so doing, protect the range of goods and services that these resources provide to society. This report highlights the complete process that has been followed in the development of a preliminary guideline for the determination of buffer zones for rivers, wetlands and estuaries. What are buffer zones? Definitions of buffer zones are variable, depending on their purpose. Buffer zones have been used in land-use planning to protect natural resources and limit the impact of one land-use on another. This project specifically looks at aquatic buffer zones which are typically designed to act as a barrier between human activities and sensitive water resources thereby protecting them from adverse negative impacts. Why are buffer zones regarded as important? Buffer zones associated with water resources have been shown to perform a wide range of functions, and on this basis, have been proposed as a standard measure to protect water resources and associated biodiversity. These functions include:  Maintaining basic aquatic processes;  Reducing impacts on water resources from upstream activities and adjoining land uses;  Providing habitat for aquatic and semi-aquatic species;  Providing habitat for terrestrial species; and  A range of ancillary societal benefits. What buffer zones do not do? Despite the range of functions potentially provided by buffer zones, buffer zones are far from a ‘silver bullet’ that addresses all water resource related problems. Indeed, buffers can do little to address some impacts such as hydrological changes caused by stream flow reduction activities (i.e. changes in flow brought about by abstractions or upstream impoundments). Buffer zones are also not the appropriate tool for militating against point-source discharges (e.g. sewage outflows), which can be more effectively managed by targeting these areas through specific source-directed controls.