Riverbank filtration (RBF), a managed aquifer recharge (MAR) technique utilised at the river–groundwater interface, can enhance groundwater quantity and quality, thus improving water supply security. However, it demands targeted local and regional monitoring strategies to understand how recharge efficiency and water quality benefits may vary with seasonal and short-term, event-based river flow fluctuations, upstream contaminant inputs, and site-specific aquifer heterogeneity. We evaluated river water–groundwater mixing and groundwater residence times to enhance the knowledge of aquifer recharge dynamics at the RBF site near Tarnów, Poland, serving as a critical drinking water source in this region. By coupling environmental tracers (stable water isotopes, chloride concentration, water temperature and specific electrical conductance) with high-resolution hydrological, meteorological and groundwater abstraction records, we show that RBF is the dominant recharge mechanism for the system that constitutes over 90 % of year-round yield from the production wells near the riverbank. Based on this example, we present a transferable and practical methodology for managing RBF systems efficiently: a multi-tracer, Ensemble End-Member Mixing Analysis (EEMMA) based workflow that covers at least one hydrological year, checks for local biases, and combines discrete water samples with continuous monitoring of physicochemical and hydrometeorological data, thus providing a robust and cost-effective template for recharge-source assessment. Such a framework determines both quantitative and qualitative status of abstracted groundwater and facilitates proactive responses to upstream pollution events and/or rapid hydrological shifts, which are crucial for sustainable water resource management internationally.

Climate change and increasing groundwater demand underscore the urgency of sustainable water resource planning. Managed Aquifer Recharge (MAR) represents a promising strategy, yet its implementation depends on accurately identifying locations suited for specific MAR techniques. This study presents a GIS-based methodology developed under the DEEPWATER-CE project for identifying suitable locations for six MAR techniques in Central Europe. The methodology integrates environmental, hydrological, and land use criteria in a two-stage approach: an initial screening to delineate potentially suitable areas, followed by a detailed classification of those areas into high, moderate, and low suitability categories. The approach was tested in the Polish part of the Dunajec River catchment (4835 km²), revealing that river or lake bank filtration, infiltration ditches, and underground dams are the most viable MAR options, suitable for 12.6%, 13%, and 15.6% of the catchment area, respectively. A focused analysis within the Tarnów agglomeration, identified as highly vulnerable to climate change and with intensive groundwater use, demonstrated that 83–87% of the area is moderately suitable for infiltration ditches and riverbank filtration techniques. This decision-support tool can inform water managers and planners regarding the best locations for implementing MAR to enhance aquifer resilience, ensure water availability, and mitigate the impacts of extreme weather events. The methodology is transferable to other regions facing similar hydroclimatic challenges.

The glacier environment exhibits a high sensitivity to global climate change, leading to progressive deglaciation and the exposure of previously ice-covered land. The newly exposed terrain provides a valuable opportunity to observe rapid ecosystem changes, such as the accumulation of glacial sediments, the development of soil-forming and progressive alterations in water and biogeochemical cycles. While developing hydrological and hydrogeological models for the Werenskioldbreen proglacial expanding zone, we encountered a significant problem due to insufficient data for parameterizing glacial sediments, which constitute the environment for water flow and storage. This study provides detailed insight into the physicochemical parameters of glacial sediments and classifies them in terms of grain size distribution, hydraulic conductivity, pH and the content of carbon (Corg), nitrogen (Nt) and phosphorus (Pt). We found that the marginal outwash plains of Werenskioldbreen are characterised by gravelly sand, sandy gravel and silty sand (28.6%, 23.8% and 19% of the total sample contents, respectively). The lateral moraine contains sandy clayey silt, silty sandy gravel or sandy gravelly silt (7.1%, 4.8% and 2.4 % of the total sample contents, respectively). The chemical parameters of young glaciofluvial sediments have lower values than those of moraines. Corg ranged from 0.07% to 2.70%. Nt was < 1.00 g kg−1 for 95% of the samples and < 0.5 g kg−1 for 81% of them. Pt was between 0.48 and 1.18 g kg−1. In line with the studies on this subject already published, we confirm that there is clear a relationship between the type of geomorphological form, its age, and the physicochemical parameters of glacial sediments.

Riverbank filtration (RBF), a managed aquifer recharge (MAR) technique utilised at the river–groundwater interface, can enhance groundwater quantity and quality, thus improving water supply security. However, it demands targeted local and regional monitoring strategies to understand how recharge efficiency and water quality benefits may vary with seasonal and short-term, event-based river flow fluctuations, upstream contaminant inputs, and site-specific aquifer heterogeneity. We evaluated river water–groundwater mixing and groundwater residence times to enhance the knowledge of aquifer recharge dynamics at the RBF site near Tarnów, Poland, serving as a critical drinking water source for this agglomeration. By coupling environmental tracers (stable water isotopes, chloride concentration, water temperature and specific electrical conductance) with high-resolution hydrological, meteorological and groundwater abstraction records, we show that RBF is the dominant recharge mechanism for the analysed system functioning, constituting over 90 % of year-round yield from the production wells near the riverbank. Based on this example, we present a transferable and practical methodology for managing RBF systems efficiently: a multi-tracer, Ensemble End-Member Mixing Analysis (EEMMA) based workflow that covers at least one hydrological year, checks for local biases, and combines discrete water samples with continuous monitoring of physicochemical and hydrometeorological data, provides a robust and cost-effective template for recharge-source assessment. Such a framework determines both quantitative and qualitative status of abstracted groundwater and facilitates proactive responses to upstream pollution events and/or rapid hydrological shifts, which are crucial for sustainable water resource management internationally.