MODFLOW-2005 and MODPATH6 models used to delineate areas contributing groundwater to selected surface receiving waters for long-term average hydrologic stress conditions from 1968 to 1983, Long Island, New York

A regional groundwater-flow model and particle-tracking program were used to delineate areas contributing groundwater to coastal and freshwater bodies and to estimate travel times from the water table to saline water bodies under average conditions from 1968 to 1983 on Long Island, New York. The coastal waters of Long Island are important economic and recreational resources for the region. The coastal water bodies receive freshwater from inflow of both surface water and groundwater, in addition to tidal exchanges of saltwater. Excessive nitrogen inputs associated with development and urbanization in the freshwater recharge areas to coastal water bodies can adversely affect marine and estuarine ecosystems. The results from this study will be beneficial for developing informed strategies to address nutrient loading to these systems, to provide a basis for additional scientific studies, and to engage the public. This is the first phase in the development of an updated groundwater-flow model for Long Island as part of the National Water Quality assessment Program (NAWQA). The study modified and used the model documented in the publication 'Simulation of the effects of development of the ground-water flow system of Long Island, New York by Herbert T. Buxton and Douglas A. Smolensky (https://pubs.er.usgs.gov/publication/wri984069). This data release contains all of the model input and output files for the simulations described in the associated model documentation report (https://dx.doi.org/10.3133/sir20165138).