San Marcos River at San Marcos water level
River gauge, San Marcos River, Texas, United States
Right now
Low for mid-October
Water level
- Flow
- 94.9 cfs
History
20252026
What this means
At 3.67 ft, the San Marcos River at San Marcos is below normal for mid-October.
The median for mid-October is 4.66 ft, based on 30 years of readings, so the river stage is 0.99 ft below typical. On the same day last year the reading was 3.53 ft, a difference of +0.14 ft.
It has barely moved over the past 24 hours. Without real rain upstream, that is unlikely to change quickly. Over the past 30 days it has moved between 3.59 ft and 3.76 ft.
Fall is often low-water season on rivers, and it usually takes a few days of steady rain to change that.
Compared with 30 years of daily readings for this time of year. How to read levels
Key numbers
- Median for this date
- 4.66 ft0.99 ft below the median for this date
- Normal for this date
- 3.46 ft – 5.37 ft8 years in 10 fall in this range (30 years of records)
- Same day last year
- 3.53 ft+0.14 ft
- Lowest and highest in 30 days
- 3.59 ft – 3.76 ft
- Lowest and highest in 12 months
- 3.47 ft – 4.11 ft
- Highest on record
- 21.29 ftOctober 17, 1998
What the stage means on the water
Low water means more dragging on shallow riffles and slower floats. Fish crowd into the deeper runs, and warm, low water stresses them, so play and release them quickly.
Highest crests on record
| Rank | Level | Date |
|---|---|---|
| 1 | 21.29 ft | October 17, 1998 |
| 2 | 10.77 ft | July 8, 2002 |
Weather at the gauge
The forecast is not available right now.
Map
Other gauges on the San Marcos River
| Gauge | Level | Compared with normal | 24 hours | Distance |
|---|---|---|---|---|
| San Marcos River near MartindaleRiver gauge, San Marcos River | 7.40 ft | Normal | −0.03 ft | 7 mi |
| San Marcos River at LulingRiver gauge, San Marcos River | 3.66 ft | Very low | +0.01 ft | 23 mi |
Nearby gauges
| Gauge | Level | Compared with normal | 24 hours | Distance |
|---|---|---|---|---|
| Blanco River at San MarcosRiver gauge, Blanco River | 7.19 ft | Below flood stage | −0.20 ft | 1.6 mi |
| Blanco River near KyleRiver gauge, Blanco River | 26.18 ft | Very high | ±0 | 6 mi |
| Blanco River at Halifax Rch near KyleRiver gauge, Blanco River | 0.83 ft | Low | −0.02 ft | 8 mi |
| Blanco River at WimberleyRiver gauge, Blanco River | 3.51 ft | Low | +0.01 ft | 12 mi |
| Onion Creek near DriftwoodRiver gauge, Onion Creek | 1.14 ft | Normal | −0.02 ft | 14 mi |
| Guadalupe River at SattlerRiver gauge, Guadalupe River | 4.45 ft | Normal | ±0 | 15 mi |
| Guadalupe River at Third Crossing near SattlerRiver gauge, Guadalupe River | 3.81 ft | Normal | +0.01 ft | 15 mi |
| Hueco Spgs near New BraunfelsRiver gauge, Hueco Spgs | 7.14 ft | Normal | +0.01 ft | 15 mi |
Questions and answers
Is the San Marcos River at San Marcos higher than last year?
Yes, it is 0.14 ft higher than on the same day last year, when the reading was 3.53 ft.
What is a normal level for the San Marcos River at San Marcos in mid-October?
The median for mid-October is 4.66 ft. In 8 years out of 10 the reading falls between 3.46 ft and 5.37 ft, based on 30 years of records.
Is gage height the same as water depth?
No. Gage height is measured from a fixed reference point chosen by the agency, so a reading of 10 ft does not mean the river is 10 ft deep.
What is the water level of San Marcos River at San Marcos today?
On Oct 18, 2026, 03:45 PM CDT, the water level was 3.67 ft. Steady over the last 24 hours.
Is San Marcos River at San Marcos rising or falling?
Steady over the last 24 hours. Steady over the last 7 days.
Is the level of San Marcos River at San Marcos normal?
Low for mid-October. Compared with 30 years of daily readings for this time of year.
What is the highest water level ever recorded at San Marcos River at San Marcos?
The highest level on record is 21.29 ft on October 17, 1998.
For specialists
Station codes, datum, parameters, data quality and downloads
- Operator
- U.S. Geological Survey
- Station code
usgs:08170500(Agency page)- Coordinates
29.88911, -97.93417(WGS84)- Vertical datum
- NAVD88
- Update interval
- every 15 minutes
- Licence
- Public domain. Data: U.S. Geological Survey (USGS), provisional data subject to revision
Published series
| Parameter | Last value | Time (UTC) | Quality |
|---|---|---|---|
| Water level | 3.67 ft | 2026-10-18 20:45 | Provisional |
| Flow | 94.9 cfs | 2026-10-18 20:45 | Provisional |
Download
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How to cite
U.S. Geological Survey: San Marcos River at San Marcos (usgs:08170500). Accessed October 18, 2026 via Nivelmap, https://nivelmap.com/en/united-states/texas/san-marcos-river-at-san-marcos
How we check values
Each reading is stored as published. We hold back values that jump faster than physically plausible and show the measurement time with every value.
Readings are provisional, can be delayed or wrong and are not a flood warning. Read the disclaimer