The aim of this book is to instruct engineering students and junior engineers in the principles and practice of engineering hydrology. As far as practicable this is done through the use of examples and calculations. The fourth edition of this popular and long-established textbook has been completely revised and reset. Chapter 2 has been expanded to include the latest work on probable maximum precipitation by the world Meteorological Organization. New material on consumptive use of crops in irrigation practice is provided in Chapter 3, and a new simple method of dilution gauging is described in Chapter 6. There are two completely new chapters on urban hydrology and world-wide examples of flood frequency growth curves. Finally, the chapter on design criteria has been enlarged to include a discussion on risk analysis.