Texas SWAT+ modeling
Cowleech Fork Sabine River (USGS 08017200), in the Upper Sabine basin: documented SWAT+ USGS station model snapshot with Explorer-aligned maps.
Case study basin: Upper Sabine
Below is a documented SWAT+ model-build snapshot for the Upper Sabine watershed—the same export class as Watershed Explorer. The metric strip, maps, charts, NHD flowline-length summary by feature class, and fact tables follow from that committed export.
The metric strip, fact tables, and optional DEM/CDL maps describe the exported SWAT+ workspace for Upper Sabine (HUC8 12010001). NHD-linked stream statistics and PRISM climate headers follow the same conventions as other SWATGenX state sample models across CONUS.
Counties in the basin overlay: Hunt.
- Runoff timing and climate variability across multi-year forcing
- Channel routing and NHDPlus HR hydrography linkage
- Land cover and HRU discretization for management screening
- Reproducible SWAT+ package delivery via SWATGenX
Basin distributions (Upper Sabine · Texas)
CDL charts use the same basin-clipped raster summary as Explorer watershed reports. County population bars use US Census county-or-equivalent polygons only (not state, city, or township layers): one published headcount per county that intersects the basin, then summed for screening—not watershed-apportioned density.
CDL land cover (basin clip)
CDL cropland & permanent crops (share)
Population by county (overlay)
Land-cover mix (km², CDL clip)
Climate forcing (Upper Sabine · Texas)
Monthly climatology from basin PRISM precipitation and temperature, and NSRDB humidity and solar radiation files. The line is the mean daily value for each calendar month (averaged across all station files and years); the shaded band is the P05–P95 spread of those daily values (2000-01-01 – 2024-12-31). 22 weather grid cells (4 km) used by the model: PRISM precipitation and temperature, NSRDB humidity, solar radiation and wind.
Precipitation
mm day⁻¹ (PRISM)Relative humidity
% (NSRDB)Solar radiation
MJ m⁻² day⁻¹ (NSRDB)Daily maximum temperature
°C max (PRISM)Daily minimum temperature
°C min (PRISM)Key facts
The first table lists basin id, climate window, CDL and population context, and the two published stream-length definitions (channel routing versus NHD-linked stream GIS). The strip above still carries headline structure counts (HRUs, channels, lakes).
| Metric | Value |
|---|---|
| WBD HU8 name | Upper Sabine |
| USGS gauge | 08017200 |
| WBD region (VPUID) | 1201 |
| Model domain | 207.94 km² |
| USGS-reported drainage area (NWIS site record) | 209.79 km² |
| SWAT+ stream GIS segments (NHDPlusID → NHDFlowline) | 752 |
| Stream length — channel routing (rivs1, projected) | 415.64 km |
| NHD-linked stream length, GIS projected | 423.35 km |
| DEM resolution (m) | 29.98 |
| CDL cropland (basin clip) | 16.88 km² |
| CDL wetland (Woody + Herbaceous) | 0.19 km² |
| CDL developed | 9.38 km² |
| Population (by county, Explorer overlay) | 99,956 |
| Counties (gov. units) | 1 |
| Climate period (PRISM header) | 2000-01-01 – 2024-12-31 |
| Stats exported (UTC) | 2026-10-25 15:57 UTC |
| SWATGenX snapshot ID | 1201/usgs_station/08017200 |
| Snapshot label | Upper Sabine (Texas) — usgs_station |
| Model statistics generated (UTC) | 2026-10-25T15:57:59Z |
How to read this table: each row starts from Watershed/Shapes/SWAT_plus_streams.shp, where each segment carries NHDPlusID. Those IDs join to NHDFlowline in the USGS NHDPlus HR HU4 geodatabase (VPUID 1201). Lengths add in EPSG:5070 (planimetric km) and roll up by NHD FType / FCode. Row lengths sum to 423.35 km over 752 segments.
| NHD class (label) | Length (km) | Share | Segments |
|---|---|---|---|
| Stream / river (intermittent)FType 460 · FCode 46003 | 402.29 | 95% | 567 |
| Artificial path (NHD)FType 558 · FCode 55800 | 11.65 | 2.8% | 173 |
| Stream / river (perennial / general)FType 460 · FCode 46006 | 4.98 | 1.2% | 10 |
| Canal / ditchFType 336 · FCode 33600 | 4.42 | 1% | 2 |
The county total matches the bar chart: county-or-equivalent units only (cities and townships excluded), one Census headcount per county intersecting the basin. Screening context only—not basin density or a regulatory design population.
Documented SWATGenX SWAT+ package for Texas (1201/usgs_station/08017200). Screening and documentation only—not a regulatory determination.
What SWATGenX generates
SWATGenX assembles national inputs, runs the QSWAT+ / SWAT+ Editor workflow, and exports a reviewable SWAT+ workspace (TxtInOut + GIS + SQLite). Open the package in SWAT+ Editor for scenarios; add calibration and validation with local data where your study requires it.
National datasets (labels)
This sample build uses NHDPlus HR at 1:24k, 30 m terrain (from 10 m 3DEP), 250 m NLCD land use (from 30 m), 250 m gSSURGO soils (from 30 m), ~4 km PRISM weather, and daily NSRDB values at the same 4 km grid cells (from ~4 km, 30-minute data). See SWAT+ model packages by state for the full stack. Methodology & provenance.
Citations for on-page facts
- Hydrologic catalog: USGS WBD — USGS station 08017200 (HUC12-located SWAT+ model)
- Hydrography: USGS NHDPlus HR — each SWAT+ stream segment (``NHDPlusID``) joined to HU4 ``NHDFlowline`` (FType/FCode); lengths summed in EPSG:5070 for the distribution table.
- Land cover (CDL): USDA NASS Cropland Data Layer (clipped to basin)
- Climate forcing: PRISM Climate Group (OSU), daily met files referenced in weather-sta.cli
- Regional population context: USGS Census county-or-equivalent polygons (GU_CountyOrEquivalent) clipped to the basin — one headcount per county, summed for screening (not basin-apportioned density; cities and townships excluded).
SWAT+ in Texas — common questions
- How do I run SWAT+ in Texas? Use SWATGenX to screen basins in Texas on the Watershed Explorer map, then queue a SWAT+ model build for a USGS gage, catalog HUC12, or HUC8. The platform assembles national datasets into a SWAT+ Editor package without manual QSWAT+ desktop prep for each basin. The sample model on this page is the Cowleech Fork Sabine River watershed above USGS 08017200, in the Upper Sabine basin.
- What is the difference between SWAT and SWAT+ in Texas? SWAT (legacy) and SWAT+ (current process-based watershed model) both support long-term hydrology and water-quality studies in Texas. SWATGenX targets SWAT+ and delivers reproducible, high-resolution projects on NHDPlus HR hydrography.
- Can SWATGenX build SWAT+ models for Texas watersheds? Yes. SWATGenX covers CONUS, including Texas, with the same national data stack (WBD, NHDPlus HR, PRISM, NLCD, gSSURGO). Each state page documents a sample basin snapshot from a real SWATGenX build; open the live map at https://www.swatgenx.com/watershed-workspace to model your own watershed.
- How do I get a SWAT+ model for Texas on SWATGenX, and what does it cost? Create a SWATGenX account to build SWAT+ models for Texas: a free account keeps 1 model, and Starter and MAX keep more. The MAX and Department plans add larger builds and a steady-state MODFLOW 6 groundwater model built with each SWAT+ model (offered in Michigan Lower Peninsula, Indiana, Minnesota, Ohio, Wisconsin), and cloud calibration is on every plan, paid from calibration credit; prices for every plan are listed at https://www.swatgenx.com/pricing.
Open Upper Sabine in Watershed Explorer
Preview uses the USGS WBD boundary with NHDPlus HR context, zoomed to basin extent on a Streets-style basemap. Follow the card into the live workspace (HUC8 12010001).
