This working paper examines the institutional frameworks governing water security in Ethiopia and their implications for conflict prevention in the Horn of Africa. It argues that Ethiopia's domestic water governance is characterised by sectoral fragmentation and weak transboundary coordination, which exacerbates regional hydro-political tensions. Through a qualitative case study analysis, the paper identifies key institutional gaps in policy integration, data sharing, and stakeholder engagement. The findings suggest that without significant institutional reform, Ethiopia's unilateral development of the Nile Basin, particularly the Grand Ethiopian Renaissance Dam (GERD), will continue to be a source of interstate friction, undermining broader regional water security and stability.