Assessment of groundwater depletion caused by excessive extraction through groundwater flow modeling: the Celaya aquifer in central Mexico

A numerical groundwater flow model was developed for the Celaya aquifer in central Mexico to assess the potential impacts of excessive groundwater use in the region. The numerical simulations were made with the program FEFLOW, which allowed the use of an irregular mesh that was adjusted to boundaries with irregular geometries and refined in wells and streams. Considering mountain block hydrology, both diffuse and stream-focused recharges were simulated. Hydraulic properties were assigned according to the three-dimensional distribution of lithologic units, which were estimated using geological information from the region. The model was calibrated using static water level measurements in wells and qualitative information of some hydrological processes. Some of the trends observed in the residuals were related to time-constant boundary conditions which can only be solved by developing a regional groundwater flow model. The simulations were undertaken for predevelopment, present, and future scenarios, up to the year 2030. The future simulations considered two possible scenarios: (1) future extractions are equal to current extractions; and (2) future extractions increase gradually in time. The results show that current groundwater extractions are not sustainable in the long term and decreases in extraction rates are required to achieve sustainable groundwater use in the region.