The book, designed for the postgraduate students of Pure and Applied Geology (M.Sc.) and Hydrology and Groundwater (M.Tech), and undergraduate students of Civil Engineering/Irrigational Engineering/Water Resource Engineering, is highly useful to the students for their course study. It is also likely to help those appearing in various competitive examinations such as GATE, NET, PSC and UPSC. This book comprises fifteen chapters, of which the first six chapters are devoted to Hydrology, whereas the last nine chapters impart the knowledge of Groundwater. The text explains topics in a simple manner using step-by-step approach throughout and supports learning with illustrations and diagrams.