Modeling Evaluation of Increasing the Allowable Excavation Depth of the Mine
Client: Titan Florida, LLC (sub-consultant to WSA, Inc.)
The Corkscrew Mine operated by Titan Florida LLC, is located in Lee County, Florida. The operator is submitting a request to Lee County for a Mine Excavation Planned Development (MEPD) to increase the allowable excavation depth of the mine. A recent MODFLOW modeling study by Cardno was completed to evaluate the potential effects of the proposed changes to mining depth. The key indicators for determining impacts to the groundwater system were changes in aquifer heads in conservation areas within the site and changes in aquifer heads at the flow-ways. However, the client requested an additional evaluation by using an integrated surface water / groundwater model.
The MIKE SHE/ MIKE11 model developed recently for South Lee County by Lago as part of the South Lee County Watershed Initiative was the starting point for this evaluation. New observation station data was entered in the model for verification purposes. Surface water features in the MIKE11 component were updated or added from information collected during a field visit.
The updated model performance was verified by using the observation station data. Then, two models were derived by using the current and the proposed allowable excavation depth of the mine.
The average water table level maps during the wet and dry season were subtracted to evaluate the impacts of the new proposed depth.