Resource use efficiency is very important aspect for sustainable development, in this book practical aspects of the cost of groundwater extraction, impact of groundwater depletion on farm income, water use efficiency, technical efficiency (TE) in crop production & costs of groundwater depletion among different categories of farmers have been recorded in the Indian State of Karnataka, where groundwater is the major source of irrigation. Data have been collected from over-exploited (OE), semi-critical (SC) & safe villages. The functional analysis shows farm income is lower in OE & SC villages compared to safe villages. The mean TE in crop production has been found highest among farmers in OE villages. The total cost of groundwater depletion has been reported more in OE villages & the cost increases with increase in the size of holding. The impact of this cost was maximum on small & marginal farmers. The study has emphasized on the need for incentivizing for efficient use of groundwater by adopting efficient irrigation technologies to ensure livelihood security. The book would be of interest to students, researchers & professionals in the area of agricultural & rural development.