San Antonio River Near Mcfaddin Flow Report
As of July 29, 2026, San Antonio River Near Mcfaddin is flowing at 635 cfs with a gage height of 17.57 ft, receding 16% over the past 24 hours. Source: USGS gauge #08188570, refreshed throughout the day.
Historical Data
San Antonio River Near Mcfaddin at a glance
How San Antonio River Near Mcfaddin is running right now, where it sits on the map, and the key gauge stats.
San Antonio River Near Mcfaddin is flowing at 635 cfs, with the water sitting 17.57 ft at the gage. Flow is down 16% since yesterday as the gauge recedes.
This is USGS gauge #08188570 in Texas. Over the past 10 days the average has been 2,743 cfs, peaking at 5,810 cfs.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the Texas flow report.
Engineering Data
Flow-duration statistics and observed peak-flow context computed from this gauge’s complete daily record (USGS #08188570).
Estimate flows at an ungauged site
Drainage-area ratio transfer from this gauge . Most reliable for hydrologically similar sites in the same watershed with area ratios between roughly 0.5 and 1.5.
Percentiles are flow-duration values computed from this gauge’s observed daily record as archived by Snoflo. Return periods are Weibull plotting-position estimates from observed annual maxima, provided as general reference context only. Always verify against official USGS NWIS records. Part of Snoflo for Engineering.
Streamflow Forecast
Over the next 5 days, San Antonio Rv Nr Mcfaddin is expected to recede from today's 635 cfs, toward roughly 442 cfs by 2026-08-03 (likely range 156-1251 cfs) -- about normal for the date.
Powered by PULSE — Snoflo’s forecast engine, trained on this gauge’s full record of storms, snowmelt, and dry spells.
| Date | Expected (p50) | Likely range (p25–p75) | vs normal | Projected stage |
|---|
How does this compare to past years?
Year-over-year overlay, annual peak discharge, the full distribution of daily flows on record, and the gauge's rating curve.
Weather Forecast
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day forecast
Daily temperatures, snow, and rain projected over the next two weeks.
San Antonio River Near Mcfaddin
The river's major constituents are runoff from precipitation events and groundwater discharge. The streamgauge is located upstream of the Guadalupe River and its tributaries, and there are no major dams along the river. The flow rate tends to increase during the rainy season in the summer and fall and decrease during the dry season in the winter and spring. Interestingly, the river is home to several endangered species, including the Texas blind salamander and the San Marcos gambusia.
Nearby streamflow levels
Cross-check San Antonio River Near Mcfaddin's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| San Antonio River Near Mcfaddin | 635 cfs |
| Guadalupe River Near Tivoli | 1,580 cfs |
| Guadalupe River Near Bloomington | 618 cfs |
| Guadalupe River At Sh 35 Near Tivoli | 1,530 cfs |
| Coleto Creek Near Victoria | 2 cfs |
| North End Of Gbra Calhoun Canal Near Long Mott | 6 cfs |
River levels & flood safety
- Read the level before you go
- A river that's runnable at one flow can be deadly at another. Check current discharge and gage height — like the values shown above — against the flood-stage thresholds, and remember levels can spike fast after rain or a dam release.
- Respect cold water
- Snowmelt rivers run cold even in summer. Sudden immersion triggers cold-water shock and saps strength within minutes. Wear a PFD, dress for the water temperature (not the air), and never wade or paddle alone.
- Watch for swiftwater hazards
- Strainers (downed trees), undercut rocks, and low-head dams are the deadliest features on moving water. High, fast, muddy water hides them. If in doubt, scout from shore and portage.
- Mind flash floods & releases
- Narrow canyons can flood from a storm miles upstream, and dam-controlled reaches can rise without warning. Know the forecast, the release schedule, and your exit before you launch.
Track San Antonio River Near Mcfaddin in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when San Antonio River Near Mcfaddin crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About San Antonio River Near Mcfaddin
What is the San Antonio River Near Mcfaddin flow rate right now?
As of July 29, 2026, San Antonio River Near Mcfaddin is flowing at 635 cfs. The live value, gage height, and 24-hour trend are shown at the top of this page.
Is the San Antonio River Near Mcfaddin running high or low right now?
Check the percent of median figure on this page: above 100% means San Antonio River Near Mcfaddin is running higher than normal for the date, below 100% means lower. The 24-hour trend shows whether it's rising or falling.
Where does the streamflow data for San Antonio River Near Mcfaddin come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 08188570. Snoflo refreshes the time series throughout the day. Forecasts come from the NOAA / yr.no feed Snoflo's iOS app uses.
How often is the report updated?
USGS gauges report continuously (typically every 15 minutes). Snoflo pulls fresh values throughout the day — look for the "as of" timestamp on the streamflow hero card.
What's the difference between discharge and gage height?
Discharge (cubic feet per second, or cfs) is the volume of water flowing past the gauge each second. Gage height is how high the water sits at the gauge (feet). They're related by a rating curve specific to each gauge — higher water means more flow, but the exact ratio depends on channel shape.
How is "percent of median" calculated?
Today's discharge is compared to the historical median discharge on this calendar day across the gauge's full record. 100% = right on median; 200% = a very high year; 30% = a drought-level low.
What are flood stages, and is this river safe right now?
Flood stages are NWS-defined gage-height thresholds — Action, Minor, Moderate, Major — marking when nearby roads or floodplains start to be affected. "Safe" depends on your activity and skill: a level that's a fun paddle for an expert can be lethal for a wader. Always check the current level against the thresholds above and the safety links, and when in doubt, stay off the water.
Can I get alerts when San Antonio River Near Mcfaddin rises?
Yes — flow alerts are managed in the Snoflo iOS app. Favorite this gauge, set a streamflow threshold (e.g. "alert me when discharge crosses 5,000 cfs"), and you'll get a push the moment USGS reports the crossing.
Access the free San Antonio River Near Mcfaddin report
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