This book, explains this science of Hydrology in a very simple and lucid language. Besides explaining the hydrological analysis of essential topics like rainfall, infiltration, evaporation, runoff, etc., the book provides a detailed description of floods and flood control methods, including flood forecasting & emergency evacuation. The art of storage of flood flows in dam reservoirs and underground storages, for supplying water during non-monsoon months, has also been lucidly explained in this book, besides covering the rarely available topics like hydrology of coastal aquifers and wells in oceanic islands. Desalination of salty sea water, for making it fit for human consumption in coastal cities, is an other important subject, which has also been explained in detail. Topics like Computer Applications in Water Resources Systems, and Engineering Economy in Water Resources Planning have also been included. The text matter has been further supported with more than 600 Objective Questions, including those from the various competitive examinations.