This book gives a brief outline of the general principles governing the occurrence of groundwater in a predominantly hard-rock terrain of Karnataka and indicates the extent of this resource. It is intended to serve as an introduction to groundwater hydrology of the State and be of assistance to all those who are concerned and interested with the evaluation, planning and development of groundwater resources. Emphasis is laid on the importance of conjunctive use of surface and groundwater resources to meet the growing demand for water in the years to come.