Skip to main content

Person

Donald A Walter

Hydrologist (Geol)
Email: dawalter@usgs.gov
Office Phone: 518-285-5600
Fax: 518-285-5601

Location
District Office - Troy
425 Jordan Road
Troy , NY 12180
US
thumbnail
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...
thumbnail
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...
thumbnail
MODFLOW 6 Model Used to Simulate Groundwater Flow in the Long Island, New York Regional Aquifer System for 1900–2019 Pumping and Recharge Conditions
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...
thumbnail
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...
thumbnail
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...
View more...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.