MODFLOW is the USGS's modular hydrologic model. MODFLOW is considered an international standard for simulating and predicting groundwater conditions and groundwater/surface-water interactions.
Originally developed and released solely as a groundwater-flow simulation code when first published in 1984, MODFLOW's modular structure has provided a robust framework for integration of additional simulation capabilities that build on and enhance its original scope. The family of MODFLOW-related programs now includes capabilities to simulate coupled groundwater/surface-water systems, solute transport, variable-density flow (including saltwater), aquifer-system compaction and land subsidence, parameter estimation, and groundwater management.
Current MODFLOW Core Version: MODFLOW 6
MODFLOW 6 is presently the core MODFLOW version distributed by the USGS, but MODFLOW-2005 (the previous core version) is still actively maintained and supported.
»Download MODFLOW-2005 v.1.12.00
MODFLOW Utilities, Post Processors, and Graphical User Interfaces (GUIs)
The USGS software below are the most commonly used USGS MODFLOW utitilities.
FloPy is a Python package to create, run, and post-process MODFLOW-based models.
GW_Chart is a graphing application for MODFLOW, Zonebudget, and other codes. GW_Chart also converts binary cell-by-cell flow files to text files.
ModelMuse is a GUI for MODFLOW-2005, MODFLOW-LGR, MODFLOW-NWT, MT3DMS, PHAST, MODPATH, and ZONEBUDGET.
Model Viewer is a program for 3D visualization of groundwater-model results.
ZONEBUDGET is a program for computing subregional water budgets for MODFLOW.
Additional MODFLOW Utilities »
MODFLOW-Based Particle Tracking and Solute Transport
MODPATH is a particle-tracking post-processing model that computes flow paths using output from MODFLOW.
MT3D-USGS is a groundwater solute transport simulator for MODFLOW.
MODPATH-LGR is a variation of MODPATH Version 5 that has been modified to work with nested grid output produced by MODFLOW-LGR.
SEAWAT is a combined version of MODFLOW and MT3DMS for simulation of variable-density groundwater flow and transport.
Groundwater Transport (GWT) Package
GWT incorporates the capability to simulate solute transport with MODFLOW.
Parameter Estimation and Uncertainty Analysis
PEST++ is an objected-oriented universal parameter estimation code written in C++ that can be used to calibrate MODFLOW models
UCODE is a universal parameter estimation code that can be used to calibrate MODFLOW models.