The most populated and industrialized region of Latin America, the Metropolitan Region of São Paulo host 18 millions people in 39 municipalities. The urban water services are managed in a centralized way by a state firm which provides for a domestic demand of 63 m3/s of which 50% is imported from a neighbouring catchment. Half of the water comes from the periurban catchments of the agglomeration which are submitted to a rapid subnormal urbanization with inadequate sanitation arrangement that directly impact the quality of the water. The tensions are likely to increase with the increasing population and difficulties for the sanitation authorities to keep pace with the urbanization processes. Land management is under the responsibility of the municipalities but a specific land legislation to control urbanization in the catchment defined in the 70's did not permit to control urbanization. The implementation since 1995 of an integrated water management policy has permitted to implement multi-stakeholder platforms for water managemen called catchment commiteet, to better articulate land management and water management, as well as to facilitate the participation of civil society in the process.