An existing three-dimensional model (MODFLOW-2000) by Petkewich and Campbell was modified to simulate potential changes in groundwater-level conditions caused by withdrawals from a proposed well in the Middendorf aquifer near Monocks, South Carolina. A single well was added to the existing model in the cell at row 67 and column 119 in layer 7 (the Middendorf aquifer). Two scenarios were created by modifying the Base Case simulation which is documented in the model documentation report (https://pubs.usgs.gov/sir/2009/5185/) and data release (https://doi.org/10.5066/F7JW8C1K). The proposed well was pumped at 0.5 million gallons per day for the 'proposed well 1.5 MGD' scenario and 1.5 million gallons per day for the 'proposed well 1.5 MGD' scenario. This was the only change made to the model for this data release. This data release was created at the request of Mount Pleasant Waterworks to document the effects of a proposed well. This data release contains all of the model input and out files needed to run the model simulations described above. Data tables and figures of the model output are included in the ancillary directory. The data release also includes MODFLOW-2000 source code used to run the model simulations.