Groundwater Numerical Simulation in an Open Pit Mine in a Limestone Formation Using MODFLOW

Numerical groundwater simulations of a complex limestone formation quarry in northern Spain enabled problems there to be quantified. A conceptual model of the aquifer, based on extensive in situ field work and information analysis was developed using MODFLOW. Steady state simulations as well as a first transient simulation were performed. The predictions matched the measured flows in the pit reasonably well, allowing practical scenarios of immediate interest to be simulated. Model calibration suggested a new permeability zonation, dependent of the degree of fracturing. The model provides a consistent quantitative framework with which new tests or operations can be evaluated in a cost effective manner.