The article analyzes the relationship between patterns of interaction state-society and the dynamic management of water resources in Brazil, from a parallel between the implementation of this policy and the model proposed by Nunes (1997; 2003), on the four grammars policies institutionalized in the country. Discusses the need for consolidation of new institutions face the issue of water from the Law No. 9433/97, which regulates the National Water Resources Policy (PNRH) and Decree No. 8.243 / 14 establishing the National Policy on Social Participation. Points out, in his concluding remarks, the emergence of participation as a fifth grammar to be incorporated into the Brazilian political structure to strengthen deliberative spaces and expansion of structures that allow alternative means of dealing with conflict.

O artigo busca apurar e discutir os resultados produzidos pelo Comitê de Bacia Hidrográfica do Baixo Paraíba do Sul e Itabapoana (CBH BPSI) relacionados ao ambiente institucional: a efetividade da lei e a importância do tema para a agenda pública. O procedimento metodológico envolveu pesquisa documental em atas, notas técnicas, resoluções, relatórios de gestão, entre outros documentos produzidos pelo CBH e/ou por sua agência de bacia. Os dados primários foram levantados a partir da observação não participante [como técnica preponderante] e entrevista não estruturada [de forma complementar], a fim de demonstrar o aspecto da governança assimilado e o resultado apresentado pelo CBH BPSI nos três biênios estudados - correspondentes ao período de 2011 a 2017. Os dados indicam que o CBH BPSI tem demonstrando ser uma instituição que tende a ser efetiva na governança das águas, ainda que apresente limitações associadas ao desenho do sistema e ao contexto em que essas instituições operam.Palavras-chave: Governança. Águas. Efetividade. Políticas públicas.GOVERNANCE IN HYDROGRAPHIC BASIN COMMITTEE OF THE LOW PARAÍBA DO SUL AND ITABAPOANA: effectiveness of the law and importance of the theme for the public agendaAbstractThis article seeks to investigate and discuss the results produced by the Lower Paraíba do Sul and Itabapoana River Basin Committee (CBH BPSI) in respect to the institutional environment: the effectiveness of the law and the importance of the theme for the public agenda. The methodological procedure involved documentary research, technical notes, resolutions, management reports, among other documents produced by CBH and / or its basin agency. The primary data were collected from non-participant observation [as preponderant technique] and unstructured interview [in a complementary manner] todemonstrate the assimilated governance aspect and the results presented by CBH BPSI in the three biennia studied - corresponding to the period from 2011 to 2017. Data indicate that CBH BPSI has been shown to be an institution that tends to be effective in water governance, even though it has limitations associated with the system design and the context in which these institutions operate.Keywords: Governance. Waters. Effectiveness. Public policies.