Computational systems in civil engineering hydraulics and hydrology include both process dedicated situations and modelling. Applications include: data acquisition, management, archiving, and presentation; application programs in areas such as meteorology, hydrology, hydraulics, water quality modelling, fluid mechanics, and coastal and ocean engineering; program maintenance and support; documentation and text processing; and real-time control.Hardware and software systems are undergoing rapid development in all these areas. Emerging techniques make it possible to supplant event modelling, and its associated design storm methodology, with more rational continuous modelling, using Atmospheric Environment Services archives, statistical processing of output, and graphics input/output. Continuous modelling, however, leads to data management difficulties. Special software for time series management is essential.Sophisticated data base management systems and local area networks permit improved cost performance. The paper reviews some of these developments and discusses the inevitable evolution of distributed data processing using multi-microcomputer-based data management systems for civil engineering computational hydraulics and hydrology. For concurrent process control and modelling, the authors recommend a local area network of desk-top microcomputers, each assigned individual hydrological modules, communicating with a central hard disk boss microcomputer. Some specifications are suggested. Key words: computational hydrology, computational hydraulics, microcomputer systems, data base management, local area networks, time series management, emerging computer techniques.