           1 WATER POLITICS IN BRAZIL: SUBSIDIARITY AND HUMANITY ASPECTS FOR THE SEMI ARID SUSTAINABLE RIVER BASIN MANAGEMENT 1 Patricia Borba Vilar Guimarães, Yanko Marcius de Alencar Xavier 2 ABSTRACT This paper examines Brazilian national constitutional law interpretation about water resources management, environmental protection and sustainable development principles. Institutional scenario is characterized under an economical format, important to conciliate human rights guaranties, national development and water protection. We provide subsidies for legal and institutional analysis considering human rights and an equity desirable scenario. Istitutional context in Brazil assumes that Federal Law No. 9433/97 determined that water management must improve its multiple uses, decentralization and social participation. Water resources management in Brazil is legally and institutionally marked by the presence of the subsidiarity principle. We analyze the case in current national scene, with its consequent conflict in São Francisco River Basin, a semi arid Northeastern River Basin. This work also reflects some aspects of water pricing as defined by State politics. Some parameters are discussed as an elementary presupposition for water regulatory instruments that will define respective water management policy. Therefore, when defining criteria water fees, laws must comply with constitutional principles and the parameters established by the Brazilian Water Law (Law 9.433/97). The lack of reasonability and proportionality in dealing with the formal aspects and, specially, in defining water allocation, can obstruct the subsidiary principle application as determined by the Law 9433/97 and National Water Resources Policy. The question is observed in a more detailed focus over Northeastern Brazilian semi-arid region, where scarcity and traditional relations on politics are difficult to deal with, according to a renewed vision of the State and sustainable development principles. 1 Esse artigo foi originalmente apresentado no 7th International Science Conference on the Human Dimensions of Global Change (IHDP MEETING 2009), em Bonn, Alemanha. 2 Professores do Departamento de Direito Público da Universidade Federal do Rio Grande do Norte.