Water Resources Applications Software


MODular three-dimensional finite-difference ground-water FLOW model with the Hydrograph Package (see documentation below) added

Notice: This USGS product has been superseded by a newer product. USGS no longer updates this page, but it may be useful as a reference or resource. To find the current core version of MODFLOW, please see


Selection of the following options preceded by a binary icon retrieves a compressed UNIX tar file or a self-extracting DOS executable. A README file containing installation instructions is included with each of the software distribution files.

MODFLOW-96 compiled for...

[BINARY ICON] IBM-compatible PC, 386 or higher with math coprocessor (includes source for HYDMOD and related programs) (798 kb)

This is version 3.3h of MODFLOW-96, which adds the hydrograph package to version 3.3 of MODFLOW-96.

New postprocessors included with MODFLOW

HYDFMT: Program for converting binary output from HYDMOD package to ascii files.

HYDPOST: Program for converting head or drawdown from MODFLOW to ascii files.


HYDMOD Package documentation, PostScript, file (305 K)

   HYDMOD Package documentation, Portable Document Format (PDF) (662K)

Hanson, R.T., and Leake, S.A., 1999, Documentation for HYDMOD, a program for extracting and processing time-series data from the U.S. Geological Survey's modular three-dimensional finite-difference ground-water flow model: U.S. Geological Survey Open-File Report 98-564, 57 p.

USGS Privacy statement
USGS Disclaimer statement

Web page comments, contact: Richard Winston <>
U.S. Geological Survey
431 National Center
Reston, VA 20192

Last Iteration: October 20, 2015