Managed Aquifer Recharge in Bangladesh: A Review of Practices, Groundwater Responses, and Implications across Diverse Geological Contexts

Groundwater depletion and salinity intrusion have deepened concerns over the long-term reliability of freshwater resources across Bangladesh, stimulating increased attention to the role of Managed Aquifer Recharge (MAR) in strengthening water security. The review examines the development, implementation, and performance of MAR across two distinct hydrogeological settings: the Barind Tract in the northwest, where groundwater levels are rapidly declining, and the coastal zone in the southwest, where salinity limits access to freshwater. The study evaluates the development of MAR practices in Bangladesh and synthesizes evidence on the effectiveness of major MAR techniques, including Rainwater Harvesting Systems (RWHS), Aquifer Storage, Transfer and Recovery (ASR/ASTR), and Induced Bank Filtration (IBF). RWHS installations, which rely on rooftop and stormwater capture, typically recharge shallow aquifers ranging from 140 to 1,070 m 3 /year. ASR/ASTR systems using treated pond or surface water achieve recharge capacities of up to 3,600 m 3 /year, although their performance is influenced by water turbidity, filter clogging, and aquifer properties. IBF systems provide substantially larger recharge volumes, reaching up to 31,200 m 3 /day where permeable riverbank sediments permit efficient infiltration; however, their effectiveness is reduced in areas with thick clay layers. Findings highlight the dominant role of geological variability in determining the suitability and long-term performance of MAR interventions. The study emphasizes the need for site-specific hydrogeological assessments, operational monitoring, and coordinated strategies that integrate technology, policy support, financing mechanisms, and community participation. Strengthening these elements is essential for enhancing groundwater sustainability and improving resilience in drought-sensitive and salinity-prone regions. • MAR in Bangladesh has evolved irregularly across regions and technologies. • Most MAR initiatives have been implemented through foreign-funded projects. • MAR suitability varies across Barind and coastal zones due to diverse geology. • MAR techniques show contrasting recharge capacities and operational constraints. • Sustainable MAR requires site-specific assessment with strong local capacity and policy support.