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 Fact Sheet: Understanding and Managing the Effects of Groundwater Pumping on Streamflow

  Annotated List of Classic Pre-1980 USGS Groundwater Papers on Quantitative Groundwater-Flow Analysis

  WaterNow: Get current water conditions by text or email

 Groundwater's Greater Role in Waterways Demonstrated in Virginia

  Circular: Streamflow Depletion By Wells: Understanding and Managing the Effects of Groundwater Pumping on Streamflow

 MODPATH v6 released

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MODPATH: A Particle-Tracking Model for MODFLOW

• MODPATH Version 6 Overview
• What's New in Version 6
• Information and Downloads
• Point of Contact
• Links and Disclaimers

MODPATH Version 6 Overview

MODPATH is a particle-tracking post-processing model that computes three-dimensional flow paths using output from groundwater-flow simulations based on MODFLOW, the U.S. Geological Survey (USGS) finite-difference groundwater flow model. The program uses a semianalytical particle-tracking scheme that allows an analytical expression of a particle's flow path to be obtained within each finite-difference grid cell. A particle's path is computed by tracking the particle from one cell to the next until it reaches a boundary, an internal sink/source, or satisfies another termination criterion.

Data input to MODPATH consists of a combination of MODFLOW input data files, MODFLOW head and flow output files, and other input files specific to MODPATH. Output from MODPATH consists of several output files, including a number of particle coordinate output files intended to serve as input data for other programs that process, analyze, and display the results in various ways.

MODPATH is written in FORTRAN and can be compiled by any FORTRAN compiler that fully supports FORTRAN-2003 or by most commercially available FORTRAN-95 compilers that support the major FORTRAN-2003 language extensions.

What's New in Version 6

MODPATH Version 6 is more efficient and easier to use than previous versions of MODPATH. The changes to MODPATH Version 6 also provide an improved code base for incorporating future changes. The major changes to MODPATH Version 6 include:

• streamlined and simplified data input that makes pre-processor development and data management easier.
• improved performance for particle-tracking simulations based on transient MODFLOW simulations.
• additional attributes for particle-tracking output files that provide more information for post-processing applications.
• improved support for double-precision calculations.
• a redesigned programming style that will make it easier to support local grid refinement (LGR) in future versions.

Information and Downloads: MODPATH v6.0.01, released August 24, 2012

• MODPATH Version 6.0.01 Release Notes [3KB TXT]
• Download MODPATH Version 6.0.01 program, source code, user guide, and example problems [6.4MB ZIP]
• The MODPATH Output Examiner is a Microsoft Windows application for viewing and analyzing output from MODPATH Version 6.
• Superseded Versions (Note: these versions are no longer supported)
  • MODPATH version 4.3
  • MODPATH version 5

Point of Contact

Support is provided for correcting bugs and clarification of how MODPATH is intended to work. Only limited assistance can be provided for applying MODPATH to specific problems by contacting the point of contact listed below:

David Pollock
U.S. Geological Survey (USGS) Office of Groundwater
411 National Center
12201 Sunrise Valley Drive
Reston, VA 20192

Other USGS Groundwater Software

The USGS develops groundwater , water-quality, surface-water, and other water-resources software for use by the USGS in fulfilling its mission. Most of this software is available online for download at no charge.

Disclaimers and Notices

Please refer to the USGS Software User Rights Notice for complete use, copyright, and distribution information. The USGS provides no warranty, expressed or implied, as to the correctness of the furnished software or the suitability for any purpose. The software has been tested, but as with any complex software, there could be undetected errors. Users who find errors are requested to report them to the USGS.

References to non-USGS products, trade names, and (or) services are provided for information purposes only and do not constitute endorsement or warranty, express or implied, by the USGS, U.S. Department of Interior, or U.S. Government, as to their suitability, content, usefulness, functioning, completeness, or accuracy.

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