ABSTRACT
Rivers have been the great nurturer of human civilisation. An environmental flow is the water regime provided within a river, wetland or coastal zone to maintain ecosystems and their benefits where there is competing water uses and where flows are regulated. Environmental flows provide critical contributions to river health, economic development and poverty alleviation. Environmental flow assessment is a means of describing the potential trade-offs between development gains, such as increased use of water for agriculture or industrial production, and environmental losses, for instance reduced habitats for aquatic plants and animals or reductions in the quality of life of subsistence users of the river. Hydraulic methods relate various parameters of the hydraulic geometry of stream channels to discharge. The ecotope method is a new approach for assessing environmental flow requirements and it enables integration of river and floodplain ecosystems and their functions.
