Rio Grande at Castolon, TX
River level and flood forecast · Brewster County
Normal2.2 ftas of Mon 2:15 PM
The river is 12.8 ft below flood stage (15 ft).
Flow: 8 cubic feet per second (USGS).
The last 7 days and the forecast
NWS forecast issued Sat, Sep 26, 8:54 AM. Forecasts change as rain falls and as upstream water arrives.
Flood stages
| Major flood stage | 24 ft |
| Moderate flood stage | 19 ft |
| Flood stage | 15 ft |
| Action stage | 13 ft |
| Record crest (September 27, 1958) | 24.7 ft |
What floods at each level
From the National Weather Service, highest first.
- 24.7 ftthe river reaches record stage (1978), and results in major flooding of Cottonwood Campground. All area roads are submerged.
- 19 ftthe river reaches moderate flood stage, and begins flooding Cottonwood Campground. The river inundates the restrooms upstream at Santa Elena Canyon parking lot. The river begins to close all area roads.
- 15 ftthe river reaches minor flood stage, and lowland flooding begins. The river begins to flood the road between Santa Elena Canyon and Cottonwood Campground in Big Bend National Park. The river begins to flood the parking lot at Santa Elena Canyon, and cut off the nature trail into the canyon. Campers in Cottonwood Campground need to prepare for possible evacuations.
- 13 ftthe river reaches bankfull, and no significant damage is expected.
Highest crests on record
- 24.7 ft — September 27, 1958
- 24.6 ft — October 3, 1932
- 23.25 ft — September 22, 2008
- 21.3 ft — September 30, 1978
- 21.15 ft — September 21, 1974
Recent crests: 17.81 ft (September 25, 2026) · 17.99 ft (July 20, 2026) · 19.35 ft (July 4, 2025) · 17.09 ft (July 2, 2025) · 15.98 ft (June 30, 2025)
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (CSTT2); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.