The book contains sections of the edited Proceedings of the Second International Conference in Computer Methods and Water Resources held at Marrakesh from February 20-22, 1991. It is divided into three volumes the contributions of which are classified in the following sections: Vol. 1 entitled Groundwater Modelling and Pressure Flow: Groundwater and aquifer modelling.- Hydrodynamics and contamination.- Pressure Flow. Vol. 2 entitled Computational Hydraulics and Hydrology: Open Channel Flow.- River Hydraulics (Steady State, Unsteady State, Dain Breaking).- Surface and Subsurface Hydrology.- Transport Phenomena (Free Surface Flow Wave Propagation, Coastal Dynamics, Turbulent Flow).- Environmental Aspects. Vol. 3 entitled Computer Aided Engineering in Water Resources: Water Resources Planning and Management.- Computer Aided Engineering Systems.- Data Acquisition and Processing.- Remote Sensing.- Hydraulic Structures.- Boundary Element Methods.