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Water Software > Groundwater Software > MODFLOW and Related Programs > GWM

GWM: Groundwater Management Process for MODFLOW Using Optimization

Overview of GWM

GWM is a Groundwater Management Process for the U.S. Geological Survey modular three-dimensional groundwater model, MODFLOW. GWM uses a response-matrix approach to solve several types of linear, nonlinear, and mixed-binary linear groundwater management formulations. Each management formulation consists of a set of decision variables, an objective function, and a set of constraints. There are two different versions of GWM that are actively supported and available for use:

  • GWM-2005: This is currently the standard version of GWM and is based on MODFLOW-2005. GWM-2005 was first released in 2009.
  • GWM-VI (Version Independent): This version of GWM can be used with any version of MODFLOW that meets certain requirements on input and output. This version also allows parallel processing of the MODFLOW runs required to solve an optimization problem. This version was first released in 2013.

A third version of the software, GWM-2000, has been superseded but is provided below for historical reference and for those still using MODFLOW-2000.

GWM-2005 Information and Downloads

[Image: Cover of software documentation report. ]

Software Downloads

Note: Users are encouraged to read the documents that are provided in the 'doc' directory of this software distribution.

Documentation of GWM-2005

GWM-VI Information and Downloads

[Image: Cover of software documentation report. ]

Software Downloads

Note: Users are encouraged to read the documents that are provided in the 'doc' directory of this software distribution.

Documentation of GWM-VI

Example Applications of GWM

Superseded Version: GWM-2000

GWM-2000 is based on MODFLOW-2000. It does not support all of the functionality that has been developed for GWM-2005 and GWM-VI. Although the code is provided for users still working with MODFLOW-2000, it has been superseded by GWM-2005 and GWM-VI. The software version(s) below are provided online for historical reference only, and the pages may contain outdated information or broken links.

Points of Contact

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

U.S. Geological Survey
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

This software has been approved for release by the U.S. Geological Survey (USGS). Although the software has been subjected to rigorous review, the USGS reserves the right to update the software as needed pursuant to further analysis and review. No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. Furthermore, the software is released on condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use. Also refer to the USGS Water Resources Software User Rights Notice for complete use, copyright, and distribution information.

Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

See also, USGS policy on linking to non-Federal web sites.

Software License and Purchase Information

This software is a product of the U.S. Geological Survey, which is part of the U.S. Government.


This software is freely distributed. There is no fee to download and (or) use this software.


Users do not need a license or permission from the USGS to use this software. Users can download and install as many copies of the software as they need.

Public Domain:

As a work of the United States Government, this USGS product is in the public domain within the United States. You can copy, modify, distribute, and perform the work, even for commercial purposes, all without asking permission. Additionally, USGS waives copyright and related rights in the work worldwide through CC0 1.0 Universal Public Domain Dedication ( [Link exits USGS]).

Note: Some or all of this information is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of the free Adobe Reader from the Adobe web site. [Link exits USGS] Visit [Link exits USGS] for free tools that allow visually impaired users to read PDF files.

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Page Last Modified: Wednesday, 28-Dec-2016 01:31:57 EST