Cost-benefit Analysis of Indirect Groundwater Recharge Scheme using Recycled Water in a Semi-arid Region

Abstract This study aimed to conduct a cost-benefit analysis of an innovative large-scale treated wastewater reuse for indirect groundwater recharge project that was implemented in the Kolar district of Southern India. The cost of the project and the agricultural benefits were obtained from various government organizations. The results of the study indicate a considerable increase in the cropped land area and productivity after the recycling period. The assured supply of water resulted in significant improvements in cropped area, cropping intensities, leading to higher revenues. Additionally, there was a boost in milk collection and related revenues, as well as a 6-fold increase in silk cocoon production. Year-round filled tanks resulted in > 25-fold increase in fish production, leading to higher revenues. Furthermore, the recycling project had a positive impact on employment opportunities, promoting sustainability, the local economy, and environmental responsibility. The cost-benefit analysis confirmed that the project's benefits exceeded the costs, with a net present value of ₹40,100 million rupees @ 5% and ₹27,103 @8% interest rates on fixed capital cost, and a benefit-cost ratio of 5.30 (@ 5%) and 4.26 (@ 8%). The recycling project could significantly enhance the agro-economic system and ensure food security and a circular economy.