Assessing the Impact of Conjunctive Use of Rainwater and Groundwater: Empirical Evidence from Semi-arid Regions of Karnataka

The escalating depletion of groundwater resources, especially in water-scarce regions, underscores an urgent need for sustainable solutions. Rainwater harvesting (RWH) emerged as a vital strategy to counteract this groundwater depletion. This study aims to provide empirical evidence on the impact of farm ponds and their combined use with groundwater on farmers’ income. Utilizing a multistage sampling approach, plot-level data were collected from 450 participants across four distinct agroclimatic zones spanning eight districts in Karnataka. The endogenous switching regression model was used to analyse the impact, and the findings revealed that the income of farm pond adopters increased approximately 70% compared to rainfed farms. Farmers practising conjunctive use experienced a substantial income boost––a 37% and 33% rise compared to farms solely using farm ponds and conjunctive use with groundwater, respectively. In addition to household characteristics, our study underscored the pivotal role of institutional and social factors in adoption decisions. The article addressed a primary concern associated with farm ponds—the perceived land wastage due to construction. Considering a farm pond with an area of 90 square metres, the study demonstrates a significantly higher opportunity cost foregone, amounting to ₹16,363 in farm ponds and ₹6,470 in conjunctive use. JEL Classification: Q00, Q15, Q16