OBJECTIVES: A key challenge for achieving universal water access in Sub-Saharan Africa is poor sustainability of water schemes. Previous studies have posited factors that may lead to failed schemes; however, empirical data are lacking. METHODS: We conducted direct observations of water sources and interviewed water committee members about governance in two regions of Ethiopia. Based on direct observation at each water point, and harmonizing previous research in the sector, we developed an ordinal measure of functionality. Among functional systems, linear regression models were used to assess changes in score or level of functionality against governance characteristics. RESULTS: Of 89 water schemes over 5 years old, 82 had sufficient data to receive a score. Higher functionality scores were associated with having good records, meeting regularly, financial audits, higher monthly fees, a paid caretaker and water committees with capacity to perform minor repairs. CONCLUSIONS: Our continuous measure of functionality was simple to derive, objective and may be widely applicable for further studies assessing key indicators of sustainability.