Effectiveness of Artificial Recharge Structures in Enhancing Groundwater Storage: A Case Study

Objectives: The effectiveness of recharge structures in enhancing the recharge process has been evaluated for different recharge structures, namely, check dam and percolation pond with percolation wells, individually as well as in a combined manner. Methods: These structures have been constructed and monitored for their effectiveness through field pilot scale studies in a watershed in Tamil Nadu. The effectiveness was assessed in terms of increase in groundwater table, improvement in the quality of groundwater and the percentage of recharged quantity in terms of water storage created by the recharge structures using water level fluctuation method and mass balance approach. Natural recharge was estimated by water balance method. Findings: An average increase in water level of the order of 2m to 3m was observed in the surrounding areas of individual recharge structures, whereas in the area surrounding the combined recharge structures, an increase of around 5m in the groundwater table was observed after 2 years of artificial recharge. According to mass balance study the percentages of the volume of water contributed for recharge of the aquifer was worked out to be 79 percent and 92 percent for check dam and percolation pond with percolation wells respectively. The Total Dissolved Solids (TDS) and hardness were observed to be considerably reduced after the construction of artificial recharge structures. Percolation pond with percolation wells was found to be the most favorable structure in the watershed studied. Applications: This paper has demonstrated the comparison of situations with and without artificial recharge structures and these recharge structures are highly effective in enhancing groundwater resource.