The Use of EFlows Assessments in Basin-Planning and Design of Hydropower Operating Rules

Environmental Flows (EFlows) are a vital way of mitigating the effects of human developments on rivers and estuaries, and thus for managing water resources for long-term sustainability. Modern EFlows assessment methods, based on ecosystem-modeling approaches, address the complexity of river ecosystems and their responses to infrastructure projects for development. For any considered scenario, they can provide quantitative estimates of a range of environmental indicators and offer possible options for biodiversity offsets and other mitigation. Quantified or semi-quantified information such as this has only become available to developers and decision-makers in the last decade or so, and is currently being used to guide development and restoration initiatives in rivers across Central and Southeast Asia. Using regional examples, the presentation will illustrate the scope of the EFlows assessments undertaken, the kinds of information provided, and the different uses made of the information generated in project-specific and basin-wide development planning and restoration initiatives.