MODFLOW-USG
MODFLOW-USG: A free, self-hosted MODFLOW variant for irregular grids and specialized groundwater systems. Ranked #6 of 11 in Groundwater Modeling Software by our editors (7.8/10); pricing: Free plan; best for unstructured grids and complex well or conduit systems.
At a glance
- Editor score7.8 / 10
- PricingFree plan
- Best forUnstructured grids and complex well or conduit systems
- Free planYes
- Paid fromFree
- Flow modeling methodFinite-difference
- Facts checked24 Sep 2026
Where it wins
- Handles structured, unstructured, nested, and multi-shape grids
- Models arbitrary cell connectivity with Ghost Node Correction
- Represents multi-node wells, karst conduits, tile drains, and networks
Where it doesn't
- Self-hosted deployment requires local installation and management
- Support is provided through email rather than broader channels
- Flow-focused scope suits fewer transport and surface-water workflows
Our verdict on MODFLOW-USG
MODFLOW-USG is a USGS groundwater-flow model for teams working with structured or unstructured grids, nested layouts, multiple cell shapes, and complex subsurface connections. Its control-volume finite-difference formulation allows each cell to connect to an arbitrary number of adjacent cells. That makes it a practical fit for mid-market and enterprise modeling groups handling irregular geometries, connected well systems, karst conduits, or tile drains. The software is open source and supplied for self-hosted deployment.
The published offering is free and includes the program, source code, user guides, and example problems for download. There are no paid tiers to compare. Teams manage installation and operation themselves, with email listed as the support channel. For numerical work, MODFLOW-USG includes a sparse matrix solver package with multiple linear solution schemes. An optional Newton-Raphson formulation addresses convergence and drying or rewetting issues, giving modelers additional control when standard solution behavior is insufficient.
Its standout capability is geometric and network flexibility: the generalized Ghost Node Correction package supports irregular or nested grid geometries, while the Connected Linear Network process links groundwater flow with features such as multi-node wells, karst conduits, and tile drains. The scope is centered on groundwater flow, so teams seeking solute-transport or surface-water-coupling workflows should evaluate a broader MODFLOW option. Choose MODFLOW-USG when arbitrary connectivity and specialized conduit or well representations matter most; choose another tool when a wider process portfolio is the priority.
Your product? Our editors can test MODFLOW-USG in depth and publish a review, labelled as paid · from $149/mo →
MODFLOW-USG pricing
MODFLOW-USG fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| Flow modeling method | Finite-difference |
| Transport modeling | Not verified |
| Surface-water coupling | Not verified |
| Model dimensions | Not verified |
| GIS data exchange | Not verified |
| Supported platforms | Not verified |
| Deployment | Self-hosted |
| Support | |
| Built for | Mid-market, Enterprise (editorial estimate) |
| Pricing | Free plan |
| Website | usgs.gov |
| Facts checked | 24 Sep 2026 |
Alternatives to MODFLOW-USG
- MODFLOW 6A free, open-source model for 3D groundwater flow, transport, and coupled simulations.9.3
- FREEWATA free, GIS-centered modeling environment spanning groundwater simulation, analysis and planning.8.7
- ModelMuseFree Windows GUI for preparing groundwater model inputs, not a simulator itself.8.4
See all MODFLOW-USG alternatives →
MODFLOW-USG vs the competition
- MODFLOW-USG vs MODFLOW 6
- MODFLOW-USG vs FREEWAT
- MODFLOW-USG vs ModelMuse
- MODFLOW-USG vs SUTRA
- MODFLOW-USG vs PFLOTRAN
- MODFLOW-USG vs Watershed Modeling System (WMS)
Compare MODFLOW-USG with any tool side by side →
Used MODFLOW-USG? Be the first to review it
The editor score above is our own research. What this page doesn't have yet is a reader's view — what you used MODFLOW-USG for, what worked and what didn't. No stars are seeded and no review is paid for; an editor reads every one before it appears.
Write a reviewTwo minutes · verified accounts only · read by an editor before it appears
Featured on iTechGuides
MODFLOW-USG is listed in our Groundwater Modeling Software directory. Add the badge to your site — it links back to this page.
<a href="https://www.itechguides.com/products/modflow-usg/"><img src="https://www.itechguides.com/best/badge/modflow-usg.svg" alt="Featured on iTechGuides" width="230" height="46"></a>
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update