Sustainable management of groundwater-based irrigation in arid and semi-arid climatic settings requires reliable quantification of recharge, abstraction, and water quality evolution. This study evaluates the sustainability of groundwater resources in the Kobo Valley, northern Ethiopia, by integrating spatially distributed recharge modeling, groundwater abstraction assessment, and hydrochemical analysis. Groundwater recharge was estimated using the GIS-based WetSpass model, incorporating long-term climatic data, land use, soil, topography, and groundwater depth over a 720 km² watershed. Results indicate a mean annual recharge of 83.82 mm, equivalent to 59.6 Mm³ per year, while mean annual evapotranspiration and surface runoff were 471.7 mm (339.6 Mm³) and 234.2 mm (168.8 Mm³), respectively. Groundwater abstraction from wells was estimated at 44.3 Mm³ per year, representing approximately 74% of the annual recharge, exceeding the commonly recommended sustainable yield threshold. Hydrochemical analyses reveal that groundwater is predominantly of the Na-HCO₃ water type, with sodium and bicarbonate as the dominant ions. Slight increases in salinity and sodicity were observed in intensively irrigated areas, particularly in the northern part of the irrigated farm land, attributed to high evapotranspiration and flood irrigation practices. Although current groundwater quality remains generally suitable for irrigation, the high abstraction rate and emerging salinity trends indicate increasing stress on the aquifer system. Soil analyses also reveal notable changes in salinity and nutrient levels in irrigated farmlands. The study highlights the urgent need for improved groundwater management, abstraction control, and adoption of efficient irrigation practices to ensure long-term sustainability of groundwater resources in the Kobo Valley.