In the emergencies resulting from conflicts affecting cities of the developing world, water supply is among the most essential service to restore. It is part of the urban services commonly managed by local water institutions. Partnerships between aid agencies and these institutions do not always happen because local government is rarely trusted as a reliable partner. This study tackles the problem by determining how these partnerships may influence the outcome of aid operations both in emergencies and in rehabilitation projects. It is based on case studies from Afghanistan, Sri-Lanka, Liberia, the Democratic Republic of Congo, Haiti and Chechnya. In emergency operations, findings show that partnerships do not always beneficial in the short term but prepare for rehabilitation. Current practice with rehabilitation projects maintaining a separation between large-scale interventions and community-based operations has a detrimental effect on sustainability and fails to address the needs of the most vulnerable. The study recommends a more coordinated approach reconciling sustainability and universal service.