ASCE Manuals and Reports on Engineering Practice No. 97. This book presents the ideas behind model design and use for a broad spectrum of hydraulic modeling methods. Detailed guidance is provided for selecting the modeling approach most likely to produce the data sought. This Manual provides many different methods of hydraulic modeling from which to choose as it covers an extensive assortment of modeling topics, technical issues, and strategies. Significant advances in modeling methods and the broadening of hydraulic issues addressed by means of hydraulic modeling necessitated this updated manual. Topics include: Similitude and dimensional analysis, Single-phase flow, Loose boundary flow, Gas-liquid flows, Environmental flows, Coastal and estuary processes, Ice, debris, and hydroelastic vibrations, Hydraulic machinery, Design, construction, and operation of hydraulic models, and Instrumentation and data acquisition. Five case-study examples are included to provide an overall sense of the modeling process from start to finish.