Rationale for an ecological risk approach for South African water resource management

Abstract

The principle of ecosystem protection in the South African Water Act requires that water resource management tools for a multiple stressor environment be tailored to the characteristics of the aquatic ecosystem. The requirements of the Act, the characteristics of aquatic ecosystems as well as co-occurrence of diverse stressors are considered. Although single substance criteria have a useful role, they are not sufficient for resource management within the context of the ecological reserve. It is proposed that an effectlikelihood approach has the potential to address the variability and uncertainty in management of a surface water body subject to multiple stressors. An in-stream receiving water risk objective approach might be considered. Glossary ERA Ecological risk assessment Hazardous Having the potential to cause an (undesired) effect. IFR In-stream flow requirement SAWQG South African Water Quality Guidelines Stressor An anthropogenic substance, form of energy or circumstance that may cause a loss of sustainable ecosystem function.