Managed aquifer recharge (MAR) is an important technique for improving groundwater recharge and maintaining aquifer levels. MAR has a number of advantages compared to other forms of water storage, including the wide distribution and accessibility of aquifers, relatively cheap storage and minimal evaporative loss. Managed aquifer recharge can restore over used or brackish aquifers, protect groundwater dependent ecosystems, enhance urban and rural water supplies and water quality and improve water supply security. Despite the numerous benefits and demonstrated advantages of MAR, uptake has been lower than expected. The financial and economic performance of MAR is a key determinant of its global uptake but there are very few studies that analyse of the economic performance of multiple MAR schemes. MAR schemes show a great diversity which is reflected in the wide range of costs and benefits. A standardised conceptual approach and methodology is needed to compare and assess financial and economic aspects of MAR. This study builds on previous work on the financial costs of MAR and presents a conceptual approach and methodology for assessing the benefits of MAR. This study analyses financial costs of MAR in up to 40 schemes and 10 countries. The study also reports benefits and benefit cost ratios for up to 30 schemes. The analysis shows that schemes recharging unconfined aquifers using infiltration basins with untreated water, and riverbank filtration are relatively cheap and have good benefit cost ratios. Although schemes requiring wells with substantial drilling infrastructure and or water treatment, including stormwater and wastewater recycling, have relatively low albeit positive benefit cost ratios, these schemes can offer substantial benefits. Further research is needed to include a wider range of MAR types and technologies, including a greater number of schemes from developing countries, with further consideration of the impact of different biophysical, socio-economic, legal and institutional settings.
Keywords: financial; economic; costs; benefits; managed aquifer recharge