Banu N. Bayraktar Kalle L. Jahn Donald A. Walter John P. Masterson Sarken E. Dressler Jason S. Finkelstein Jack Monti Jr. 20240819 groundwater model archive Reston, VA, USA U.S. Geological Survey https://doi.org/10.5066/P13OHFKP Donald A. Walter Kalle L. Jahn John P. Masterson Sarken E. Dressler Jason S. Finkelstein Jack Monti Jr. 2024 publication Scientific Investigations Report 2024-5044 Reston, VA, USA U.S. Geological Survey This data release contains simulation results from fifteen transient, regional-scale numerical models of the Long Island aquifer system that predict aquifer conditions resulting from possible future changes in pumping and recharge stresses and sea level altitude. These models are based on the MODFLOW 6 numerical model that is documented in Walter and others (2024), which simulates historical water levels, streamflows, and the position of the saltwater interface in response to time-varying changes in pumping and recharge stresses for the period 1900-2019. The archive for that model is available online (Jahn and others, 2024). Fifteen model-input data sets of possible future scenarios are used to simulate aquifer conditions at annual and seasonal time scales under a variety of recharge, pumping, and sea level rise (3, 6, and 9 feet) stresses. This data release contains descriptions of the fifteen model scenarios, the model input files, and software to allow the user to run the models for each of the fifteen scenarios. Detailed instructions on how to run the models are documented in ReadMe_Main.txt. First posted August 16, 2024, ver 1.0 Revised June 2025, ver 1.1 Version 1.1: This version of the dataset now includes the model files for scenario 7 (sc_7) extended out to 30 simulated years, and the 1000 mg/L shapefiles for scenario 7 (sc_7) have also been updated accordingly. The superfluous copies of the isochlor shapefiles were removed for all scenarios. Version 1.0: In this version of the dataset, scenario 7 (sc_7) was simulated for 25 years, rather than the 30 years the other scenarios were simulated. Thus, the scenario 7 (sc_7) shapefiles for the 1000 mg/L isochlors were showing results that were short 5 years of simulation. All of the scenarios each included a superfluous copy of the isochlor shapefiles (following naming convention: "sc_##_1000mgL_isochlor") that did not need to be included in the release. These superfluous copies were not described in the readme and were simply duplicates of data already in the release. This transient groundwater flow model of the aquifer system of Long Island, New York was developed to evaluate responses of the hydrologic system and freshwater-saltwater interface to changes in natural and anthropogenic hydraulic stresses. The model also provides the groundwater flow components used to define model boundaries for possible inset models used for local-scale analyses. These scenarios were developed in consultation with the New York State Department of Environmental Conservation to assist them with the management of Long Island’s groundwater resources. 20100101 20191231 publication date Complete None planned -74.1617 -71.7006 41.3608 40.3741 ISO 19115 Topic Category biota None Groundwater model MODFLOW Groundwater usgsgroundwatermodel Zonebudget Sea level rise USGS Metadata Identifier USGS:662bc586d34ea70bd5f11f46 None Long Island New York Suffolk County Nassau County Queens County Kings County None. Please see 'Distribution Info' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Kalle L. Jahn U.S. Geological Survey mailing and physical

425 Jordan Road

Troy NY 12180 (518) 285-5695 kjahn@usgs.gov This work was supported by New York State Department of Environmental Conservation Donald A. Walter Kalle L. Jahn John P. Masterson Sarken E. Dressler Jason S. Finkelstein Jack Monti Jr. 2024 publication Scientific Investigations Report 2024-5044 Reston, VA, USA U.S. Geological Survey https://doi.org/10.3133/sir20245044 No formal logical accuracy tests were conducted No formal logical accuracy tests were conducted Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record and the associated model documentation report for additional details. No formal positional accuracy tests were conducted No formal positional accuracy tests were conducted The process used to develop, calibrate, and apply the model is fully described in the model documentation report (Walter and others, 2024) 2023 Vector G-polygon 2 Lambert Conformal Conic 41.0333333333333 40.6666666666667 -74.0 0.0 2000000.0 100000.0 coordinate pair 0.6096 0.6096 International feet North_American_Datum_1927 Clarke 1866 6378206.4 294.978698213898 GS ScienceBase U.S. Geological Survey mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Digital Data https://doi.org/10.5066/P13OHFKP None 20250616 Banu Bayraktar U.S Geological Survey mailing and physical

425 Jordan Road

Troy NY 12180 518-285-5600 bbayraktar@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999