Environmental Flow Assessment at the Source of the Blue Nile River

An increase in the Lake Tana level and surface area has occurred as the result of the construction of the weir. Therefore the regulation of lake water has resulted in an overall increase of the total surface area and environmental flows of the downstream Blue Nile River. This has believed to cause problems of flooding as the amount of water stored is very large. Another important environmental issue is the need to sustain the Tis Issat Falls, by maintaining both a minimum residue flow for the river during the dry season and a significant flow on the falls in the wet season to preserve their visual amenity. This study provides sound options that could be used to improve the current situation and to alleviate the environmental problems in the downstream; especially in the vicinity of the Falls, in order to maintain the aquatic biodiversity and to keep the visual amenity of the Falls for tourists without, unduly compromising the energy. The expected beneficiaries from this study will be public organizations, research institutions, water scientists, decision makers, ecologists, environmentalists, hydrologists, and other groups.