DEVELOPMENT OF A RELATIVE RISK ASSESSMENT FRAMEWORK TO ASSESS MULTIPLE STRESSORS IN THE KLIP RIVER SYSTEM Report to the WATER RESEARCH COMMISSION by V Wepener1, P Dlamini1, GC O’Brien2, W Malherbe1 1Unit for Environmental Sciences and Management, North-West University (Potchefstroom Campus), Potchefstroom, South Africa 2School of Life Sciences, University of KwaZulu-Natal, Scottsville, South Africa WRC Report No. 2204/1/15 ISBN 978-1-4312-0714-5 November 2015 Obtainable from Water Research Commission Private Bag X03 Gezina, 0031
[email protected] or download from www.wrc.org.za DISCLAIMER This report has been reviewed by the Water Research Commission (WRC) and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the WRC, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. © Water Research Commission ii EXECUTIVE SUMMARY BACKGROUND Whilst demand for water is rapidly increasing due to population expansion, industrialization and urbanization, water supplies are increasingly coming under pressure due to resource depletion and pollution. The Klip River, its tributaries and associated wetlands have been described as one of the most heavily impacted rivers in the country being subject to every type of conceivable pollution. These included mining, urban, industrial as well as agricultural impacts. In addition to an influence on water quality there is an impact on the water level, flow regime and stream morphology of the River. Despite this, the Klip River system must still provide the necessary ecological infrastructure to satisfy basic human needs and maintain ecological processes and then also serve the other user groups, i.e.