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

CFP: Documentation of a Conduit Flow Process for MODFLOW-2005

By W. Barclay Shoemaker (U.S. Geological Survey, Fort Lauderdale, Florida),
Eve L. Kuniansky (U.S. Geological Survey, Norcross, Georgia),
Steffen Birk (Karl-Franzenz University of Graz, Austria),
Sebastian Bauer (Eberhard-Karls University of Tubingen, Germany),
Eric D. Swain (U.S. Geological Survey, Fort Lauderdale, Florida)


The conduit flow process for MODFLOW-2005 (CFP) has the ability to simulate turbulent or laminar groundwater flow conditions by:

  1. coupling the traditional groundwater flow equation with formulations for a 1-dimensional discrete network of cylindrical pipes (Mode 1, CFPM1),
  2. inserting a high-conductivity flow layer that can switch between laminar and turbulent flow (Mode 2, CFPM2), or
  3. simultaneously coupling a discrete pipe network while inserting a high-conductivity flow layer that can switch between laminar and turbulent flow (Mode 3, CFPM3).

Conduit flow pipes (CFPM1) may represent:

  • large dissolution features, such as submerged caves in carbonate aquifers or large voids from dissolution of burrowed carbonate rock;
  • voids in fractured rock;
  • lava tubes in basaltic aquifers; and
  • submerged abandoned mines.

Pipes can be fully or partially saturated under laminar or turbulent flow conditions, but should be generally horizontal and full if vertical.

Preferential flow layers (CFPM2) may represent:

  • a porous media where turbulent flow is suspected to occur under the observed hydraulic gradients;
  • a single secondary porosity subsurface feature, such as a well-defined laterally extensive underground cave;
  • or a horizontal preferential flow layer consisting of many interconnected voids.

In this second case, the input data are effective parameters, such as a very high hydraulic conductivity, representing multiple features.

The Conduit Flow Process for MODFLOW-2005 was developed with the support of the USGS Groundwater Resources Program.

CFP Information and Downloads

Release History

First official release version 1.0 was released for publication April 14, 2008.

Current version 1.8.00 was released for publication February 23, 2011. Refer to the release.txt in the download file for complete release history.

Software Downloads and Documention

Download CFP version 1.8 (13.5MB ZIP file). File includes:

  • Release history (release.txt)
  • Installation instructions (readme.txt)
  • Source code (mf2005cfp.exe)
  • Examples, documentation, and more

A list of reports & articles is also available.

Points of Contact and Support

Support is provided for correcting bugs and clarification of how the code is intended to work. Only limited assistance can be provided for applying CFP to specific problems by contacting USGS online or by directing correspondence to the points of contact listed below.

W. Barclay Shoemaker
U.S. Geological Survey
3110 SW 9th Avenue
Fort Lauderdale, FL 33315

Eve L. Kuniansky
U.S. Geological Survey
3850 Holcomb Bridge Rd., Ste. 160
Norcross, GA 30092

Eric D. Swain
U.S. Geological Survey
3110 SW 9th Avenue
Fort Lauderdale, FL 33315

User Email List

If you want to be alerted to updates in the CFP, please contact W. Barclay Shoemaker.

Related USGS Software Resources

USGS computer programs related to CFP include the following:

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.

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

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


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