In support of water-resource planning - Highlighting key management issues using DRIFT: A case study

Abstract

The DRIFT (downstream response to imposed flow transformation) methodology was applied as part of a comprehensive Reserve determination study on the Olifants-Doring River, Western Cape, South Africa. DRIFT was used to provide flow scenarios, and descriptive summaries of their consequences in terms of the condition of the river ecosystem, for examination and comparison by decision makers, managers and users. The methods used and results obtained in that study are presented and discussed in the light of the study constraints of time and money, the lack of historical data, and the urgent need to provide clear, easily-understandable information on the consequences for the river ecosystem of various tradeoffs characteristic of water resource developments. The results indicated that abstracting during high flows in winter and river restoration work can have positive ecological and agricultural returns.