Lake Tana basin is a development corridor in Ethiopia: agricultural and infrastructure investment aims at stimulating economic growth and reducing poverty. As Lake Tana is a shallow lake (average depth of 9 m) it is at high risk of sedimentation. Extensive catchment degradation driven by deforestation, overgrazing, and low levels of technology have led to great sediment inputs in the lake, with as a consequence lake level fluctuations and decreasing water storage capacity. To address these problems and to stimulate actors to undertake mitigation measures, this study will establish cause-effect relationships among basin degradation and its consequences on lake sedimentation, and propose remedial measures.