GFLOW

The Rock River Coalition worked with the USGS to develop a computer framework model using GFLOW which is used to improve the understanding of the hydrogeology of the Rock River basin. The model simulates the groundwater flow system of the basin. The computer model is a tool used to understand the hydrogeology of the basin and model the possible groundwater changes based on proposed changes.

GFLOW is a highly efficient stepwise groundwater flow modeling system developed by Haitjema Software, a subdivision of Haitjema Consulting, Inc. GFLOW is a Windows program based on the analytic element method. It models steady state flow in a single heterogeneous aquifer using the Dupuit-Forchheimer assumption. While GFLOW supports some local transient and three-dimensional flow modeling, it is particularly suitable for modeling regional horizontal flow. To facilitate detailed local flow modeling, GFLOW supports a MODFLOW-extract option to automatically generate MODFLOW files in a user defined area with aquifer properties and boundary conditions provided by the GFLOW analytic element model. GFLOW features conjunctive surface water and groundwater modeling using stream networks with calculated streamflow. The conjunctive solutions may include detailed lake waterbalance modeling. GFLOW also supports freshwater and salt water interface flow. GFLOW provides intergrated parameter optimization by use of PEST or UCODE (these programs are included).

This is a significant step in understanding important water issues for our region.