Groundwater in the Lower Namoi River catchment is crucial for irrigation but is at risk due to overuse and contamination. Monitoring data shows significant declines in groundwater levels and land subsidence. Saline water is moving into fresh water sources, and aquifers are compacting, reducing storage capacity. To ensure sustainability, researchers are studying groundwater recharge using geochemical and isotopic data to identify sources, processes, and ages of groundwater. This information will help calculate sustainable yield and protect this valuable resource.