This will prepare for the World Water Forum, to be held in Marseilles in March 2012, a large-scale celebration of this partnership, which has mobilised all water stakeholders in the territory for more than two years. The issue of a “perfect size” in water management has been a long-standing topic of debate over economic and public finance. The key question is whether an optimal size can be identified that would allow both optimal conditions for efficient water resources management and effective service delivery.