MODFLOW-2000 data sets used in two predictive scenarios of groundwater flow and pumping (1900-2050) near Mount Pleasant, South Carolina

An existing three-dimensional model (MODFLOW-2000) by Fine, Petkewich, and Campbell (2017) (https://doi.org/10.3133/sir20175128) was slightly updated to evaluate two water-management scenarios and predict the effects of increased pumpage on the groundwater flow and groundwater-level conditions in the Mount Pleasant, South Carolina area. This model was originally developed in 2007, by Petkewich and Campbell (https://pubs.er.usgs.gov/publication/sir20075126), then updated and recalibrated to conditions from 1900 to 2015. The updated model was used to simulate six scenario simulations (scenarios 1-6) for the Mount Pleasant Water Works which are published in a U.S. Geological Survey (USGS) Scientific Investigations Report (https://doi.org/10.3133/sir20175128). The archived model input and output files are available in a USGS data release (https://doi.org/10.5066/F7S181FC). In 2018, seven additional MODFLOW-2000 scenarios (numbered 7-13), using the updated and recalibrated model from 2017, were developed to evaluate additional withdrawal strategies. The archived model input and output files for these scenarios are available in a USGS data release (https://doi.org/10.5066/ P9GZEE4E). For this analysis, the model was updated to include 2016-2019 groundwater use data for the Charleston aquifer wells in the Charleston, SC area, along with several periodic tape-down measurements at two recording wells (CHN-14 and BRK-431). The model was not recalibrated for this study. Two scenario simulations were completed and the results are included in this data release. In scenario 1, Mount Pleasant Waterworks demonstrated reasonable need of 2,409 million gallons per year. This scenario simulates 5 of the 6 Mount Pleasant wells each pumping 1.32 million gallons per day from 2020 to 2050, for a total of 6.6 million gallons per day. No withdrawals from the sixth Mount Pleasant well are simulated during the 2020-2050 time period. In scenario 2, South Carolina Department of Health and Environmental Control recommended withdrawal of 1,679 million gallons per year. This scenario simulates 5 of the 6 Mount Pleasant wells each pumping 0.92 million gallons per day from 2020 to 2050, for a total of 4.6 million gallons per day. No withdrawals from the sixth Mount Pleasant well are simulated during the 2020-2050 time period. This USGS data release contains all the input and output files for the simulations described above and in the readme.txt file of this data release (https://doi.org/10.5066/P9FA07XD).