GFLOW is an analytic element model, which solves steady state groundwater flow in a single aquifer. GFLOW supports three-dimensional particle tracking, but employs the Dupuit-Forchheimer approximation, thereby ignoring resistance to vertical flow. GFLOW features a "MODFLOW extract" feature that allows a complete set of MODFLOW files to be written for a subdomain of the model. All aquifer properties and hydrological features are automatically duplicated in the MODFLOW files. Additional features are: Areas of differing aquifer properties, horizontal barriers with resistance to flow (slurry walls), 3D flow near a partially penetrating well, local transient flow near a well (Theis solution), steady state interface flow in coastal aquifers, and PEST support for parameter optimization. GFLOW supports both vector and raster graphics as background maps, including DXF, Shapefile, TIFF, JPG, etc.

GFLOW has been produced by Haitjema Software a subdivision of Haitjema Consulting, Inc. (currently Haitjema LLC). Henk Haitjema has written the GFLOW Help system and the GFLOW solver. Vic Kelson has written the original graphical user interface (GUI), which has been further developed and maintained by Mart Haitjema. GFLOW has been placed in the public domain since January 2021 and can be downloaded from an EPA website. Tech Support is provided by EPA Center for Exposure Assessment Modeling.