WATER-QUALITY MANAGEMENT IN THE CROCODILE-RIVER CATCHMENT, EASTERN TRANSVAAL, SOUTH-AFRICA

The Crocodile River catchment lies in an area which currently has one of the highest rates of sustained economic growth in South Africa and supports a diverse army of land uses. Water quality management is vita l to resource management strategies for the catchment. A Geographic In formation System (GIS) was used to display specific catchment characte ristics and land uses, supplemented with integrative overlays depictin g land-use impacts on surface water resources and the consequences of management actions on downstream water quality. The water quality requ irements of each water user group were integrated to optimise the sele ction of rational management solutions for particular water quality pr oblems. Time-series water quality data and cause-effect relationships were used to evaluate different water supply scenarios. The GIS facili tated the collation, processing and interpretation of the enormous qua ntity of spatially orientated information required for integrated catc hment management.