Incorporating flow variability into environmental flow regimes using the flow events method

Increased understanding of the ecological importance of temporal environmental variation has led to a concern that many regulated rivers lack the natural variations in flow required to maintain pre-regulation communities. Many of the existing environmental flow methods fail to adequately address this concern. This paper presents a new approach to characterizing flow variations for environmental flow studies using knowledge of the influence of flow events on biological and geomorphic processes. This approach has the advantage that ecological benefits of the environmental flow are clearly articulated, available knowledge is included in the development of flow recommendations and the method accounts for the natural dynamism in flow-related ecosystem processes by using the natural flow regime as a template for the environmental flow regime. The Flow Events Method is demonstrated in an application to the Snowy River in southeast Australia. Copyright (C) 2003 John Wiley Sons, Ltd.