Engineering hydrological resilience: Quantitative assessment of managed aquifer recharge (MAR) potential utilizing advanced horizontal flow treatment in water stressed regions

The water-stressed Barind Tract (BT) in northwest Bangladesh faces critical challenges in meeting irrigation and domestic water demands, with groundwater tables declining at rates of 0.09–0.39 m per year due to over-extraction and limited natural recharge through thick clay aquitards (21–39 m). This study evaluates the potential for managed aquifer recharge (MAR) potential across three districts of BT (Godagari, Niamatpur and Mohanpur) using integrated horizontal flow treatment units. We analyzed 376.68 km of re-excavated Kharies (natural canals) and 257.01 acres of Beels (water reservoirs), incorporating seventeen years (2005–2021) of groundwater monitoring data and nineteen years of rainfall analysis (2002–2020). Field-verified recharge rates of 29 L/min for Kharies and 162.7 L/min for Beels were used to calculate potential MAR installations using the rational formula. Our analysis identified 3,315 feasible MAR installation sites (3,251 in Kharies: Godagari-966, Niamatpur-2276, Mohanpur-9; and 64 in Beels: Godagari-4, Niamatpur-14, Mohanpur-46), capable of recharging 27.10 million m3 annually from 50.61 million m3 of surface runoff, achieving 53.5% utilization efficiency. Groundwater monitoring showed declines of 6.6 m in Godagari, 5.24 m in Niamatpur, and 1.6 m in Mohanpur over the study period. Annual rainfall averaged 1231 mm, 1414 mm, and 1132 mm respectively, with 90% occurring during May–October monsoon periods. Performance monitoring of existing MAR installations demonstrated successful water quality maintenance within national drinking water standards (ECR 2023), with parameters including calcium (59.03–63.87 mg/L), iron (0.58–0.86 mg/L), and pH (7.26–7.29) remaining within acceptable limits while achieving groundwater level improvements up to 2.01 m. The integrated treatment units overcame natural recharge limitations of 2–3 mm/day through thick clay aquitards, achieving 10,000-fold improvement in infiltration rates. This assessment provides a scalable and replicable methodology for sustainable groundwater management strategies in water-stressed regions globally, with phased implementation of identified MAR installations offering a pathway to reverse groundwater depletion trends.