We are supporting the development of a sustainable water supply system for the people of southern Madagascar through three pipelines of 18 km, 120 km and 168 km, supplying around sixty sub-networks by solar pumping. The aim of the project is to secure access to drinking and agricultural water, while strengthening the governance of the water service. Our mission is to identify, analyse and select the best management options for each pipeline, taking into account local specificities and institutional issues. We are carrying out an assessment of the current system on the Ampotaka pipeline in order to establish suitable management scenarios, then comparing 15 potential management models according to six criteria (public management, regional EPIC, delegation to the private sector). In collaboration with the Ministry, we facilitate the choice of the most suitable management model, while putting in place a mechanism for technical and financial supervision of the water service. Finally, we analyse the conditions required for replication on a national scale, in order to guarantee efficient and sustainable management of these essential infrastructures.