A three-dimensional, groundwater flow model was developed with the numerical code MODFLOW-NWT to represent changes in groundwater pumping and aquifer recharge in the Northern Atlantic Coastal Plain aquifer system from Long Island, New York to North Carolina. The model was constructed using existing hydrogeologic and geospatial information to represent the aquifer system geometry, boundaries, and hydraulic properties of the 19 separate regional aquifers and confining units within the aquifer system.
The model was calibrated using an inverse modeling parameter-estimation (PEST) technique to conditions from 1986 to 2008, the period for which data are most complete and reliable. The simulation period for this analysis spanned from predevelopment to future conditions, from 1900 to 2058. The model was used to advance the understanding of groundwater budgets and components including recharge, discharge, and aquifer storage for the entire system and for each of the statewide systems; compute historical and recent system response and project future system response to development at a scale relevant to basinwide water-management decisions; and evaluate options for hydrologic monitoring of system changes. The report ‘Documentation of a groundwater flow model developed to assess groundwater availability in the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to North Carolina: U.S. Geological Survey Scientific Investigations Report 2016–5076' (https://doi.org/10.3133/sir20165076) documents the model design and calibration, as well as several simulations to test model construction assumptions. The report 'Assessment of groundwater availability in the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to North Carolina: U.S. Geological Survey Professional Paper 1829' (https://doi.org/10.3133/pp1829) documents water-availability simulations and the resulting analysis and discussion. This USGS data release contains all of the input and output files for the simulations described in the associated reports (https://doi.org/10.3133/sir20165076) and (https://doi.org/10.3133/pp1829). This data release also includes (1) MODFLOW-NWT source code, (2) the PEST files and source code used for model calibration, and (3) the ZONEBUDGET input files and source code used for the groundwater availability analysis.