Rapid environmental changes as well as potential risks for the human health call for water quality continuous surveillance and on-line decision making. Information and communication technologies can be valuable in these areas. In this paper we present an intelligent system for water quality assessment. Some models used for pollutants propagation, the system architecture, the functional description, the distributed acquisition subsystems are presented. The main concepts are the integration of distributed and diverse information resources through wide area networking methods, but with an easy-to-use interface that makes the technical complexity completely hidden for the user. Menu driven, graphical and supported by an embedded expert system, the interface makes interaction with complex models easy. The system provides a powerful, but simple tool for river water quality management, and decision making, according to European environmental policy, guidelines, and regulations