Integrated reservoir eutrophication remediation plan: Hartbeespoort dam

The Hartbeespoort Dam is situated in a highly developed area in South Africa. Due to high nutrient loads in the dam unpleasant and even hazardous conditions occur frequently. An integrated phased management and remediation plan has been developed and is being executed at the dam. The plan provides for short to long-term actions relating to the water quality of the incoming water, and limnology of and sediments in the dam. Actions include enhanced wastewater treatment at sewage plants, in-stream treatment, continued regular monitoring, the bio-manipulation of the fish community for removal of algae and the initiation of community based fisheries. Preliminary analysis indicates that a start-up cost of about R27.3 million and annual costs of about R9.3 million are required. These costs do not include actions that could be taken at municipal wastewater treatment plants. The development and implementation of the plan are serving as case studies for various projects in the Department of Water Affairs and Forestry.