Computer modeling is a water utility's most powerful tool for managing and operating a water distribution system. This 4th edition of M32 Computer Modeling of Water Distribution Systems, describes how to build accurate water distribution system models, and use models to manage assets and solve hydraulic and water quality problems. The manual discusses how to use models to: Predict pressures and flows Evaluate layouts and designs Solve operating problems Investigate control schemes Size components Develop new or improve existing flushing programs Prioritize asset maintenance, rehabilitation, and replacement efforts Calculate energy costs Improve water quality This edition has been updated to reflect significant changes in computer modeling and the water industry. It has more information on asset management, and new chapters on model maintenance and advanced modeling applications (e.g., system reliability and real-time modeling).