Arroyo Colorado South of Mercedes water level
NWS gauge MECT2 · International Boundary and Water Commission · Hidalgo County · Rio Grande Valley
stage above a datum the NWS does not state · Nov 3, 2026 at 9:15 PM CST · 2 hours ago
- Highest NWS crest
- 8.20 ft (July 20, 2010)
- Usual range
- 0.46 to 0.62 ft
- Highest since October 4, 2026
- 1.34 ft
Last 7 days
Hourly averages of the readings. The shaded band is this gauge's usual range: the middle 80% of its readings since October 4, 2026.
How to read this gauge
The number is the stage in feet on this gauge's own scale, as the NWS publishes it. The NWS gives no datum for it, so it is not a depth and can't be compared with other gauges.
Readings the NWS marks out of service are left out, and so is any single reading more than 2 ft from the readings either side of it, which is a sensor error rather than water; a newest reading that far from the one before waits for the next to agree.
International Boundary and Water Commission runs this gauge; the National Weather Service publishes its readings, which is where this site reads them.
NWS historic crests
| Date | Crest | Above minor flood stage |
|---|---|---|
| July 20, 2010 | 8.20 ft | — |
The highest crests the National Weather Service lists for this gauge, as published, on the same scale as the reading.
Daily highs and lows since October 4, 2026
Other NWS-published gauges in Rio Grande Valley
| Gauge | Stage | Datum | NWS flood stage | Updated |
|---|---|---|---|---|
| Arroyo Colorado at Harlingen | 4.37 ft | — | — | 2 hours ago |
| Banker Inlet to Main Floodway | 106.16 ft | — | — | 50 minutes ago |
| Main Floodway South of Weslaco | 52.60 ft | — | — | 2 hours ago |
| North Floodway Near Sebastian | 8.51 ft | — | — | 2 hours ago |
| North Floodway at Llano Grande | 52.49 ft | — | — | 65 minutes ago |
| Rio Grande Near Progreso Bridge | 57.38 ft | — | — | 2 hours ago |
| Rio Grande at Anzalduas Reservoir | 104.18 ft | — | 7.8 ft below minor flood stage | 2 hours ago |
| Rio Grande at Lower Brownsville | 2.98 ft | — | 24.0 ft below minor flood stage | 2 hours ago |
| Rio Grande near Los Ebanos | 4.40 ft | — | — | 50 minutes ago |
| Rio Grande near San Benito | 34.76 ft | — | 20.2 ft below minor flood stage | 2 hours ago |
Download the readings
arroyo-colorado-south-of-mercedes.csv (CSV): every reading from the last 90 days, 2,830 rows, with time in UTC and local time, and the reading in feet on a datum the NWS does not state.
arroyo-colorado-south-of-mercedes-daily.csv (CSV): the low and high of every day since October 4, 2026.
Source. Readings from International Boundary and Water Commission, as published by the National Weather Service, which also sets the flood stages and lists the crests. The NWS name for this gauge is “Arroyo Colorado South of Mercedes”. Recent readings are provisional and can be revised. This site is not affiliated with either.