A modern, effective Water Resource Management System must carry out the following management functions: management of sectorial use of water, management of watershed interventions, environmental management, management of water supply and interinstitutional management. Currently, several different management systems have been proposed in Brazil both at federal and state level. A critical analysis of these proposals is more effective and objective when one assesses how the management functions are to be performed. An analysis is performed in this paper for the purpose of fueling discussions leading to the improvement of water resource management in Brazil.Funções executadas por um sistema de gerenciamento de recursos hídricos. Análise crítica das propostas de diversos sistemas de gerenciamento no Brasil.