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

MODFLOW: USGS three-dimensional finite-difference ground-water model

• Overview of MODFLOW
• Current Version
• Downloads and Documentation
• Point of Contact
• Additional USGS Software Resources and Disclaimers

Overview of MODFLOW

MODFLOW is a three-dimensional (3D) finite-difference groundwater model that was first published in 1984. It has a modular structure that allows it to be easily modified to adapt the code for a particular application. Many new capabilities have been added to the original model. MODFLOW-2005 is the most current release of MODFLOW.

MODFLOW-2005 (Harbaugh, 2005) simulates steady and nonsteady flow in an irregularly shaped flow system in which aquifer layers can be confined, unconfined, or a combination of confined and unconfined. Flow from external stresses, such as flow to wells, areal recharge, evapotranspiration, flow to drains, and flow through river beds, can be simulated. Hydraulic conductivities or transmissivities for any layer may differ spatially and be anisotropic (restricted to having the principal directions aligned with the grid axes), and the storage coefficient may be heterogeneous. Specified head and specified flux boundaries can be simulated as can a head dependent flux across the model's outer boundary that allows water to be supplied to a boundary block in the modeled area at a rate proportional to the current head difference between a "source" of water outside the modeled area and the boundary block.

Current Version: MODFLOW-2005, v. 1.11.00

The current version of MODFLOW-2005 is v.1.11.00, released August 8, 2013. For a complete explanation of the changes in this release and a history of past releases, refer to:

• Release Notes [25KB TXT]

Downloads and Documentation

Software Downloads

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

• Installation instructions [15KB TXT]
• MODFLOW-2005 v.1.11.00 compiled for Microsoft Windows, with source code and test problems [11.3MB ZIP]
• MODFLOW-2005 v.1.11.00 source code and sample problems converted to the Unix file structure [6MB ZIP]

Documentation of MODFLOW-2005

• Harbaugh, A.W., 2005, MODFLOW-2005, the U.S. Geological Survey modular ground-water model -- the Ground-Water Flow Process: U.S. Geological Survey Techniques and Methods 6-A16.
  This report describes the theory and input instructions at the time of the initial MODFLOW-2005 v1.00 release.
• Online MODFLOW-2005 User's Guide:
  The User's Guide is not a tutorial and is primarily intended for those already familiar with MODFLOW. The Guide includes the most up-to-date instructions and related information for the current release of MODFLOW-2005. The Guide can be used as a quick way of looking up input formats and USGS options available.
• New to MODFLOW? We recommend starting here.

Documentation of MODFLOW Processes and Packages

The table below provides quick access to the key documentation for MODFLOW processes and packages:

• Report: The official USGS report describes the theory and input instructions at the time the package or process was first released.
• Online Guide: Packages and processes often evolve over time. The Online MODFLOW User's Guide includes the most up-to-date input instructions and related details.

Superseded Versions

The following software is not actively supported by the USGS. The software has been superseded by MODFLOW-2005. The software versions below are provided online for historical reference only, and the pages may contain outdated information or broken links.

• MODFLOW-2000 (v.1.19.01, March 25, 2010)
• MODFLOW-96
  • v.3.3h, July 10, 2000
  • v.3.3, May 2, 2000
• MODFLOW-88 (v.2.6, September 20, 1996)

Point of Contact

Support is provided for correcting bugs and clarification of how MODFLOW-2005 is intended to work. Only limited assistance can be provided for applying MODFLOW-2005 to specific problems by contacting the point of contact listed below:

• Chris Langevin,
• Edward Banta, or
• Richard Winston.

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

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.

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.  Visit http://www.adobe.com/accessibility/  for free tools that allow visually impaired users to read PDF files.