In the work, a comprehensive model for predicting groundwater levels under pressure-gravity filtration is introduced. Analyzed the complex interaction of factors influencing groundwater behavior within single and multi-layered aquifer systems. Researched the impact of parameters like filtration coefficients, infiltration rates, and specific yields on the overall water balance. Established a series of numerical experiments to test the model's validity and its ability to predict groundwater level changes over time. The analysis of the numerical calculations showed that the groundwater level depends on the infiltration coefficient and the volume of inflow and outflow through the boundary and the mound of the filtration area. In numerical calculations, it was established that the groundwater level decreases over time. A sharp drop is observed within the boundaries of the filtration area of groundwater, and it mainly depends on the volume of inflow and outflow of underground water through the interface, that is a lateral inflow into a single-layer and layered filtration zones, respectively.