SWATGenX vs HAWQS
Concise comparison of two national U.S. watershed web platforms — engines, hydrography, screening, reports, and deliverables.
What this page is: A concise, product-oriented comparison between two national-scale U.S. watershed web platforms — not a judgment on EPA policy or academic merit.
What you get from each: HAWQS emphasizes EPA SWAT-based scenario workflows with preloaded national inputs at medium-resolution hydrography. SWATGenX emphasizes SWAT+, NHDPlus HR detail, real-time flood context at 16,000+ USGS stations, automated PDF reports, and packaged SWAT+ projects.
Who should read this: Teams choosing a browser workflow for U.S. basins who need clarity on engine, backbone, and deliverables.
EPA-sourced framing: EPA describes HAWQS as an interactive, web-based modeling system based on SWAT for exploring water quantity and quality outcomes. EPA’s SWAT materials summarize SWAT’s scope; SWAT+ is the restructured successor with relational/SQLite tooling per Texas A&M / SWAT+ documentation. Hydrography scale statements for NHDPlus HR follow USGS NHDPlus HR.
How EPA positions HAWQS (high level): a web-based interactive hydrology and water-quality modeling system with SWAT as the core engine, preloaded national input data, browser-based scenario setup at HUC-8/10/12 scales, and outputs through tables, charts, and maps — verify current scope on EPA’s HAWQS pages. SWATGenX emphasizes SWAT+ project packaging on NHDPlus HR, live USGS-oriented flood and rainfall screening, automated watershed PDFs, and downloadable model artifacts for CONUS workflows.
Snapshot
- Engine: SWATGenX — SWAT+ (relational toolchain). HAWQS — SWAT classic (documented SWAT 2012 rev. 685 in HAWQS 2.0 materials).
- Hydrography: SWATGenX — NHDPlus HR (~27M flowlines). HAWQS — NHDPlus V2 family at national scale.
- Screening & reports: SWATGenX includes live USGS-oriented flood screening layers and automated watershed PDFs; HAWQS targets scenario analysis rather than the same screening/report bundle.
Data backbone (citations & resolutions):
- 16,000+ USGS stations — live context via USGS Water Services (instantaneous values often ~15-minute; see USGS for provisional data caveats)
- NHDPlus HR — built from 1:24,000 NHD, 10 m 3DEP, and WBD; USGS cites on the order of ~27 million flowlines vs ~3 million in NHDPlus V2 (USGS NHDPlus HR)
- PRISM gridded climate (~4 km cells; PRISM defines a “day” as 24h ending 12:00 GMT); NLCD land cover 30 m; gSSURGO soils (gridded SSURGO per NRCS); NSRDB solar/meteorology nominally ~4 km (≈0.038°), 30-minute series — SWATGenX may resample/regrid for operations; see methodology for lineage
For full tables (HEC, SWMM, NWM, etc.), open the comparison hub (same tile as on the home page):