Medina River At San Antonio Flow Report
As of August 2, 2026, Medina River At San Antonio is flowing at 74 cfs with a gage height of 3.11 ft, rising 8% over the past 24 hours. Source: USGS gauge #08181500, refreshed throughout the day.
Historical Data
Medina River At San Antonio at a glance
How Medina River At San Antonio is running right now, where it sits on the map, and the key gauge stats.
Medina River At San Antonio is flowing at 74 cfs, with the water sitting 3.11 ft at the gage. Flow is up 8% since yesterday — a rising hydrograph.
This is USGS gauge #08181500 in Texas. Over the past 10 days the average has been 87 cfs, peaking at 112 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 #08181500).
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, Medina Rv At San Antonio is expected to recede from today's 74 cfs, toward roughly 56 cfs by 2026-08-07 (likely range 27-115 cfs) -- drier than 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.
Medina River At San Antonio
The flow is influenced by both natural factors, such as precipitation and temperature, and human factors, such as water withdrawals for irrigation and municipal use. The Medina River watershed includes several dams and reservoirs, including Medina Lake, which can impact the flow of the river. Seasonal trends show that flow is highest in the spring due to increased rainfall and snowmelt, while flow is lowest in the summer and early fall. Interesting fact: the Medina River was once an important transportation route for early settlers and was used to transport goods to and from San Antonio.
Nearby streamflow levels
Cross-check Medina River At San Antonio's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Medina River At San Antonio | 74 cfs |
| San Antonio River Near Victor Braunig Lake Near Elmendorftx | 300 cfs |
| San Antonio River At Loop 410 At San Antonio | 11 cfs |
| San Antonio River Near Elmendorf | 178 cfs |
| Salado Creek At Loop 13 At San Antonio | 12 cfs |
| Leon Creek At Ih 35 At San Antonio | 5 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Medina River At San Antonio. Spring snowmelt is the dominant driver of streamflow in mountain basins -- a deep snowpack upstream means more runoff later in the season.
| SNOTEL station | Snowpack |
|---|---|
| San Miquel River | 0 in |
Plan a trip
Reservoirs, boat launches, river runs, and fishing spots within driving distance of Medina River At San Antonio.
Boat launches
See all →
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 Medina River At San Antonio in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Medina River At San Antonio crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Medina River At San Antonio
What is the Medina River At San Antonio flow rate right now?
As of August 2, 2026, Medina River At San Antonio is flowing at 74 cfs. The live value, gage height, and 24-hour trend are shown at the top of this page.
Is the Medina River At San Antonio running high or low right now?
Check the percent of median figure on this page: above 100% means Medina River At San Antonio 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 Medina River At San Antonio come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 08181500. 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 Medina River At San Antonio 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 Medina River At San Antonio report
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