Numerical modeling of mine-dewatering projects requires specialized features that are not present in mass-use groundwater-flow codes such as MODFLOW and FEFLOW. Many features critical to modeling groundwater flow in mine settings can be found in Itasca’s MINEDW finite-element groundwater flow code. The critical features include the ability to remove elements/nodes to simulate excavation of a pit; pinch-out capability to simulate in greater detail underground mines or specific areas of hydrogeological interests; simulation of non-Darcian flow and the transition to Darcian flow as heads and hydraulic gradients decrease; calculation of seepage faces in highwalls; and changes in hydraulic parameters in time to simulate block cave mining, longwall coal operation, or relaxation around a deep, open pit. Other features of MINEDW that enhance or simplify the modeling of mine dewatering projects include the use of specified-flux or specified-head boundary conditions, which when coupled with the fault-linking routine can simulate pumping from multiple levels in a well, variable-flux boundary conditions along external model boundaries, simulation of multiple faults without adding discretization with a fault-link subroutine, the use of a collapsing or rigid grid, pit-lake infilling simulations for both passive and active scenarios, and effective coupling of large, regional groundwater models with detailed window models.
