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The DAFLOW model routes flows through a system of inter-connected one-dimensional channels and subdivides the system into a series of branches, with each branch divided into a number of subreaches. MODFLOW simulates ground-water flow through a three-dimensional grid of cells. The models are coupled by adding an exchange between each subreach and a specified ground-water cell, with the amount of flow from the stream to ground water being limited to the available streamflow. The water exchange for each subreach is computed on the basis of the stream-aquifer head difference, the streambed thickness, stream width, and streambed hydraulic conductivity.

Cost and ordering of U.S. Geological Survey printed documentation.

Software (Version 1.1)

References to commercial vendors of software products or services are provided solely for the convenience of users when obtaining or using USGS software. Such references do not imply any endorsement by the U.S. Government.

The zip files available below must be unzipped using a utility such as PKZIP for Windows. A shareware version of PKZIP for Windows is available from PKWARE.

DAFLOW executable for Windows 9x or NT or later [365 kb]

Source Code [26 kb]


Jobson, H. E. and Harbaugh, A. W., 1999, Modifications to the Diffusion Analogy Surface-Water Flow Model (Daflow) for Coupling to the Modular Finite-Difference Ground-Water Flow Model (Modflow): U.S. Geological Survey Open-File Report 99-217, 107 p.

Report, Portable Document Format (PDF) (341 kb)

MODFLOW/DAFLOW Release information

Version 1.0, April 14, 2000 -- Initial release
Version 1.1, Dec. 26, 2002 -- Updated to fix error that occurred when branches were numbered in upstream direction.

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Last Iteration: January 09, 2003