Site suitability and water availability for a managed aquifer recharge project in the Namoi basin, Australia

Study region: This study was conducted in the Namoi catchment, Australia. Study focus: Managed aquifer recharge (MAR) site suitability has been widely studied through multicriteria decision analysis (MCDA). However, the selection of areas for MAR project implementation can be a vague process with different validation approaches. The aim of this study was to create a site suitability map for MAR projects and conduct a sensitivity analysis for the selection of an area of interest (AOI) by combining highly suitable and low sensitive areas. Ten hydrologic and hydrogeologic criteria were chosen for the selection of sites for the MAR project. All criteria were reclassified and used in a MCDA that combined Analytic Hierarchy Processes (AHP) and pairwise comparisons to construct a site suitability map. Validation of the map and the AOI selected was performed using hydrograph data. Based on the AOI map, water availability and frequency were analysed using gauging station data. New Hydrological Insights for the Region: The selected AOI represents high spatio-temporal variability in natural recharge rates, highly dependent on the Namoi River streamflow. Moreover, all recharge rates in the AOI are high, particularly in the paleochannel surrounding the current Namoi River. The selected AOI coincides with an area of thick coarse sediments underlying the riverbed and demonstrates the usefulness of the proposed methodology.