<p>In recent decades, prolonged droughts and excessive groundwater extraction have led to severe resource depletion, land subsidence, and deteriorating water quality. Groundwater, as a vital source of freshwater, requires strategic management to ensure long-term sustainability. This study investigates the quantitative and qualitative dynamics of the Shamil aquifer, a critical agricultural resource in Hormozgan Province, Iran, using the MODFLOW model within the GMS software framework. Groundwater levels and Total Dissolved Solids (TDS) concentrations were analyzed over an 11-year period (2006–2016) under steady-state and transient conditions. The study evaluates three management and climatic scenarios: (1) a 30% reduction in groundwater extraction, (2) a 30% reduction in recharge due to decreased precipitation, and (3) a combination of both factors. Results indicate that reducing groundwater extraction significantly mitigates aquifer depletion, improving water levels across most regions. Conversely, a 30% decline in precipitation leads to a substantial drop in the water table, particularly in the north and northeast, where levels decrease by up to 4&#xa0;m. The combined scenario highlights that climatic variations have a stronger influence on groundwater depletion than extraction rates, underscoring the aquifer’s vulnerability to drought conditions. Additionally, the groundwater quality model reveals elevated TDS concentrations in the central, eastern, and northwestern parts of the aquifer, suggesting progressive salinization driven by over-extraction and reduced recharge. These findings emphasize the urgent need for integrated water management strategies, including controlled extraction policies, artificial recharge initiatives, and climate-adaptive water governance, to mitigate groundwater depletion and preserve water quality in the Shamil Plain.</p>