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This groundwater model archive documents a transient, regional-scale numerical model of the Long Island aquifer system that simulates hydrologic conditions for the period 1900-2019 using U.S. Geological Survey’s groundwater modeling software MODFLOW 6 (Hughes and others, 2017). The development and calibration of the numerical model is documented in Walter and others (2024). The model input and output files included in this data release are documented in the readme.txt. The model simulates historical water levels, stream flows, and the position of the saltwater interface in response to time-varying changes in pumping and recharge stresses for the period 1900-2019. This archive also contains input and output files...
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This data release contains model simulation results of a particle tracking analysis to delineate areas that provide recharge to surface waters and public-supply wells on Long Island, NY. The analysis partitions the recharge areas based on particle travel times of greater than or less than 10 years to reach the receiving surface water or well. The simulation was performed using a regional-scale numerical model of the Long Island aquifer system (Walter and others, 2020a and 2020b) for average 2005-2015 conditions. The model implements MODFLOW-NWT (Niswonger and others, 2011) to represent steady-state groundwater pumping and aquifer recharge conditions; recharge areas were identified and partitioned using the particle-tracking...
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Note: this data release is currently being revised and is temporarily unavailable. 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...
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This groundwater model archive documents a transient, regional-scale numerical model of the Long Island aquifer system that simulates hydrologic conditions for the period 1900-2019 using U.S. Geological Survey’s groundwater modeling software MODFLOW 6 (Hughes and others, 2017). The development and calibration of the numerical model is documented in Walter and others (2024). The model input and output files included in this data release are documented in the readme.txt. The model simulates historical water levels, stream flows, and the position of the saltwater interface in response to time-varying changes in pumping and recharge stresses for the period 1900-2019. This archive also contains input and output files...
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This data release contains the input, output, and model code used to run a transient simulation of a previously published (Walter and others, 2020) steady-state regional model of Long Island, N.Y. The original model code was updated to MODFLOW 6 (version 6.3.0) and incorporates monthly transient stress periods to simulate conditions from 2005-2019 following methods described in Walter and others (2020). Selected remedial stresses (groundwater extraction and return) were incorporated for select locations in southeastern Nassau County. No modifications were made to the hydrologic boundaries, model layers, or hydraulic properties specified in the original model. A uniform value of 0.25 was used to represent specific...
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The U.S. Geological Survey (USGS) assisted the Massachusetts Department of Environmental Protection (MassDEP) with the Massachusetts Estuary Project (MEP), by delineating groundwater-contributing areas to various hydrologic features including ponds, streams, and coastal water bodies, throughout southeastern Massachusetts. These contributing areas were delineated over a 6-year period from 2003 to 2008 using previously published USGS groundwater-flow models for the Plymouth-Carver region (Masterson and others, 2009), the Sagamore (western) and Monomoy (eastern) flow lenses of Cape Cod (Walter and Whealan, 2005), and lower Cape Cod (Masterson, 2004). The original USGS groundwater-contributing areas were subsequently...
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This dataset has been archived; it has been superceded by version 2.0 (March 2021), which can be found at https://doi.org/10.5066/P954DLLC. The data contained in this data release support USGS Scientific Investigations Report 2020-5023, "Distribution of selected hydrogeologic characteristics of the upper glacial and Magothy aquifers, Long Island, New York" (Walter and Finkelstein, 2020). This data release contains estimates of aquifer texture describing the Long Island aquifer system. These estimates in total can be considered a model of aquifer texture describing unconsolidated sediments in the following principal units: 1) Upper glacial aquifer, 2) Jameco aquifer, 3) Monmouth Greensand confining unit, and 4)...
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The data contained in this data release support USGS Scientific Investigations Report 2020-5023, "Distribution of selected hydrogeologic characteristics of the upper glacial and Magothy aquifers, Long Island, New York" (Walter and Finkelstein, 2020). This data release contains estimates of aquifer texture describing the Long Island aquifer system. These estimates in total can be considered a model of aquifer texture describing unconsolidated sediments in the following principal units: 1) Upper glacial aquifer, 2) Jameco aquifer, 3) Monmouth Greensand confining unit, and 4) Magothy aquifer. The Lloyd aquifer, a major aquifer on Long Island, is not included in the model due to a lack of available data. Aquifer texture...
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This dataset has been archived; it has been superseded by version 3.0 (November 2021) which can be found at https://doi.org/10.5066/P954DLLC . The data contained in this data release support USGS Scientific Investigations Report 2020-5023, "Distribution of selected hydrogeologic characteristics of the upper glacial and Magothy aquifers, Long Island, New York" (Walter and Finkelstein, 2020). This data release contains estimates of aquifer texture describing the Long Island aquifer system. These estimates in total can be considered a model of aquifer texture describing unconsolidated sediments in the following principal units: 1) Upper glacial aquifer, 2) Jameco aquifer, 3) Monmouth Greensand confining unit, and...
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This data release contains the output from a Soil-Water-Balance (SWB) model (Westenbroek and others, 2010), used to estimate potential recharge to the Long Island regional aquifer system from 1900-2019. Output data for two SWB simulations are included. The first simulation uses available land-use/land-cover datasets to estimate recharge with changing land use from 1900-2019 (referred to as the post-development simulation). The second simulation assumed a forested, undeveloped (predevelopment simulation) condition across Long Island for the same period. The same soil coverages and time-series climate data were used throughout both simulations. Potential recharge was spatially distributed as gridded output across...
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Problem The Peconic Estuary of eastern Long Island, New York, is undergoing development as the region transitions from a rural area dependent on agriculture and tourism to a suburban one with a larger year-round population. The glacial and coastal-plain sediments underlying Long Island comprise a sole-source aquifer system that supplies the region’s communities with potable water. The area surrounding the Peconic Estuary was intensely farmed prior to suburbanization. Nitrogen loading from past fertilizer use was high as estimated from historical information and the continued detection of legacy effects in the aquifer system. In some areas, the peak or bolus of agricultural nitrogen loading from practices several...


    map background search result map search result map Simulated Groundwater-Contributing Areas to Selected Streams, Ponds, Coastal Water Bodies, and Production Wells, Plymouth-Carver Region and Cape Cod, Massachusetts The Use of Solute-transport Methods to Estimate Time-varying Nitrogen Loading Rates to the Peconic Estuary Resulting from Wastewater and Fertilizer Inputs to Groundwater in Suffolk County, New York (Peconic Solute Transport) Soil-water-balance groundwater recharge model results for Long Island, NY, 1900-2019 Aquifer texture data describing the Long Island aquifer system Aquifer texture data describing the Long Island aquifer system (ver. 2.0, March 2021) Aquifer texture data describing the Long Island aquifer system (ver. 3.0, December 2021) Simulated Recharge Areas to Surface Waters and Public-Supply Wells with Travel Times Greater Than and Less Than 10 Years For Average 2005-2015 Conditions, Long Island, NY MODFLOW 6 Model Scenario used to Simulate Transient Stresses, Heads, and Flows in the Regional Aquifer System of Long Island, New York, 2005-2019 MODFLOW 6 Model Used to Simulate Groundwater Flow in the Long Island, New York Regional Aquifer System for 1900–2019 Pumping and Recharge Conditions MODFLOW 6 Model Used to Simulate Groundwater Flow in the Long Island, New York Regional Aquifer System for 1900–2019 Pumping and Recharge Conditions (In press) Simulations of the Long Island Aquifer System Response to Potential Changes in Future Hydrologic Conditions, Long Island, New York The Use of Solute-transport Methods to Estimate Time-varying Nitrogen Loading Rates to the Peconic Estuary Resulting from Wastewater and Fertilizer Inputs to Groundwater in Suffolk County, New York (Peconic Solute Transport) Soil-water-balance groundwater recharge model results for Long Island, NY, 1900-2019 Aquifer texture data describing the Long Island aquifer system Aquifer texture data describing the Long Island aquifer system (ver. 2.0, March 2021) Aquifer texture data describing the Long Island aquifer system (ver. 3.0, December 2021) Simulations of the Long Island Aquifer System Response to Potential Changes in Future Hydrologic Conditions, Long Island, New York Simulated Recharge Areas to Surface Waters and Public-Supply Wells with Travel Times Greater Than and Less Than 10 Years For Average 2005-2015 Conditions, Long Island, NY MODFLOW 6 Model Used to Simulate Groundwater Flow in the Long Island, New York Regional Aquifer System for 1900–2019 Pumping and Recharge Conditions MODFLOW 6 Model Used to Simulate Groundwater Flow in the Long Island, New York Regional Aquifer System for 1900–2019 Pumping and Recharge Conditions (In press) MODFLOW 6 Model Scenario used to Simulate Transient Stresses, Heads, and Flows in the Regional Aquifer System of Long Island, New York, 2005-2019