Watershed Modeling Software for the United States
Screen flood risk, run watershed analyses, and generate SWAT+ packages from one browser — national data, no desktop GIS prep.
- SWAT+ model creation — automated SWAT+ model creation with high resolution national data for any USGS station or HUC8 basin
- Watershed hydrology flood risk assessment — generate reports and maps of flood risk and hydrology conditions for any USGS station or HUC8 basin
- Live screening — view 16,000+ USGS stations across CONUS with flow and rainfall context
Plans & pricing — compare Free, Basic, and Pro (this page does not repeat the full plan matrix).
SWATGenX is U.S. watershed modeling software in the browser: flood screening, hydrologic context, PDF reports, and automated SWAT+ packages from national data (USGS, NHDPlus HR, PRISM, and more) — no desktop GIS prep. Built for engineers, consultants, and planners who need repeatable screening and client-ready outputs.
One stack: continental screening (live flows, return periods, rainfall context) plus optional SWAT+ on NHDPlus HR. Citations, resolutions, and caveats: Data & methodology. How we compare to other tools: Compare platforms.
Not for FEMA-certified regulatory flood maps or structure-scale hydraulics — use HEC-RAS–class workflows there; SWATGenX is triage and SWAT+ hydrology.
Access levels
SWATGenX uses Free, Basic (signed-in), and Pro for screening, reports, and SWAT+ packages. Tier names match what you see in the app after sign-in.
Where to read limits: Plans & pricing compares the three tiers and numeric limits. For capabilities, data flow, and how SWATGenX fits together, see Platform overview.
What you can do
- Flood screening & pre-assessment — real-time streamflow vs. return-period thresholds; prioritize basins before field work
- Hydrologic context — live USGS flows and MRMS / PRISM rainfall in one map workflow
- Watershed reports — floodplain, population, cropland, and stream layers in downloadable PDFs (signed-in plans)
- Scenario comparison — side-by-side basins for planning and prioritization
- Throughput — CONUS coverage without assembling national GIS stacks by hand
Watershed Explorer
The Watershed Explorer is the single entry point: select a USGS gage or HUC8 basin, view real-time flood risk, run analyses, and download reports.
Click the image for a full-size view.
Decision-ready watershed reports
PDF reports for any USGS station or HUC8 — on demand, automated, delivered by email on signed-in plans.
Typical contents
Sources and resolutions: Data & methodology.
From screening to full SWAT+ delivery
SWATGenX starts with continental screening and extends to full SWAT+ packages when you need process-based hydrology. It has already been used across hundreds of U.S. watersheds, including 628 unique hydrologic models at varied spatial scales.
- Water balance — runoff, recharge, evapotranspiration, soil moisture
- Water quality — nitrogen, phosphorus, sediment
- Agricultural indicators — crop yield and irrigation demand
- Long runs & handoff — multi-year daily outputs and downloadable SWAT+ project packages
SWATGenX does not replace QSWAT+; it automates QSWAT+ and SWAT+ Editor so you get model packages faster. System diagram: Platform overview.
CONUS coverage — click for full size.
Built on national public datasets
USGS, NHDPlus HR, PRISM, NSRDB, NLCD, and gSSURGO are wired in so you can screen watersheds and build SWAT+ packages without assembling national GIS layers by hand. Citations and resolutions: Data & methodology.
- USGS — live and historical streamflow for screening
- NHDPlus HR — hydrography and terrain backbone for routing
- PRISM, NSRDB, NLCD, gSSURGO — climate and land-surface inputs for reports and models
Appropriate use
Flood and rainfall indicators on SWATGenX are for rapid triage and planning context, not a substitute for site-specific hydraulic studies, FEMA flood insurance studies, or official emergency warnings. For methodology and citations see Data & methodology.