Development of a Regional Scale Ecological Risk Assessment Model for the management of water resources in the uMngeni Catchment, KwaZulu-Natal
The uMngeni River catchment contains a wide range of land use practices, including the economically important urban centres of Durban and Pietermaritzburg. The majority of the economically important water resource use activities in the catchment are totally dependent on the ecosystem services provided by the uMngeni River. To ensure sustainability, the balance between the use and protection of the water resources of the uMgeni River is urgently required. Since the 1960s there have been concerns related to the wellbeing of the water resources in the uMgeni River catchment due to stressors associated with water resource use. With the recent development of preliminary Water Classification classes and associated Resource Quality Objectives (RQOs) for the uMgeni Catchment the opportunity to establish a suitable balance between the use and protection of water resources may now be available. Do these RQOs address the threats to water resources adequately and if implemented will the desired balance between the use and protection of local water resources be achieved? Ecological risk assessment techniques may provide the information required to address these aims.
In this study, the Relative Risk Method (RRM) was implemented to conduct an ecological risk assessment of multiple stressors to selected ecological endpoints using macroinvertebrates as indicators in the uMngeni Catchment. Initial low confidence analyses suggest that the RQOs will address the need to achieve a balance between the use and protection of water resources and if implemented will contribute to the sustainable management of water resources in the study area.