Blanco River at San Marcos, TX
Is Blanco River at San Marcos, TX flooding right now?
Blanco River at San Marcos, TX measured 6.20 ft on 2026-09-22 22:45:00 UTC. That observation was 11.8 ft below its 18 ft flood stage. This is the latest available reading, not a guarantee of current conditions.
Gauge height
6.20 ft
Streamflow
—
Minor flooding here begins at 18 ft, with major flooding at 30 ft. The highest crest on record was 43.1 ft on Sun, May 24, 2015.
Flood stages at this gauge
| Category | Stage | Current distance |
|---|---|---|
| Action | 13 ft | 6.8 ft below |
| Minor flood | 18 ft | 11.8 ft below |
| Moderate flood | 24 ft | 17.8 ft below |
| Major flood | 30 ft | 23.8 ft below |
Highest crests on record
| Stage | Date |
|---|---|
| 43.1 ft | 2015-05-24 |
| 42.56 ft | 2015-10-30 |
| 24.71 ft | 2021-10-14 |
| 24.14 ft | 2019-05-09 |
| 20.53 ft | 2019-05-04 |
Nearby gauges
| Gauge | Distance | County |
|---|---|---|
| San Marcos River at San Marcos, TX | 1.5 mi | Hays County |
| San Marcos River near Martindale, TX | 5.2 mi | Caldwell County |
| Blanco River near Kyle, TX | 6.9 mi | Hays County |
| Blanco River at Halifax Rch near Kyle, TX | 9.0 mi | Hays County |
| Blanco River at Wimberley, TX | 13.3 mi | Hays County |
Get a flood alert for this gauge
Free email alerts when this gauge approaches flood stage are coming soon. Leave your email and you'll be first in line.
One email when alerts launch, then only flood notifications. No spam, unsubscribe anytime.
Provisional data: Real-time readings are provisional and subject to revision by the USGS — sensors can be affected by ice, debris, or equipment malfunction. Do not rely on this site for decisions involving personal safety; follow official guidance from the National Weather Service and local authorities.