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Web Portal Changes: The Advanced Hydrologic Prediction Service (AHPS) hosted at will be replaced by the National Water Prediction Service (NWPS), with a target of March 2024. Existing AHPS content and features will be preserved and expanded within NWPS.

Experimental National Water Center Products: Flood Inundation Mapping services are now available for 10% of the U.S. population. Please visit for more information. The National Hydrologic Discussion, Area Hydrologic Discussion, Flood Hazard Outlook, and real-time geospatial services depicting River Forecast Center and National Water Model forecasts, continue to be accessible via the URL above, as described in the StoryMap here.

Hydrograph River at a Glance Download
Rio Grande at Anzalduas Reservior Pool (ft)Flow (cfs)Observed: 102.51 ft at 7:00AM Sep 25, 2023Observed: 102.55 ft at 7:00AM Sep 26, 2023Observed: 102.68 ft at 7:00AM Sep 27, 2023Observed: 102.78 ft at 7:00AM Sep 28, 2023Highest Observation: 103.09 ft at 7:00AM Sep 29, 2023MADT2(plotting HPIRZ) Graph Created (6:31PM Sep 29, 2023)ObservedLatest observed value: 103.09 ft at 7:00 AM CDT 29-Sep-2023. Flood Stage is 112 ft
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Tabular Data (UTC)
Tabular Data (CDT)
XML Data
RSS Files
Datum: Not Available
NOTE: Forecasts are not available for the Rio Grande at Anzalduas Reservior. Only observed stages are available for this point.
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Upstream Gauge - at Rio Grande City Upstream Gauge
Flood Categories (in feet)
Major Flood Stage: 121
Moderate Flood Stage: 116
Flood Stage: 112
Action Stage: 110
Low Stage (in feet): 0

Historic Crests
(1) 111.44 ft on 07/20/2010
(2) 108.27 ft on 10/15/1971
(3) 107.97 ft on 09/23/1971
(4) 104.79 ft on 08/27/1976
(5) 103.81 ft on 09/20/1988
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(P): Preliminary values subject to further review.

Recent Crests
(1) 111.44 ft on 07/20/2010
(2) 88.85 ft on 09/12/1997
(3) 93.24 ft on 11/29/1996
(4) 86.45 ft on 09/23/1995
(5) 85.79 ft on 05/15/1995
Show More Recent Crests

(P): Preliminary values subject to further review.

Low Water Records
Currently none available.
Zoom Level:16
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Gauge LocationGauge Map Marker
Latitude/Longitude Disclaimer: The gauge location shown in the above map is the approximate location based on the latitude/longitude coordinates provided to the NWS by the gauge owner.
Flood Impacts & Photos Collapse
If you notice any errors in the below information, please contact our Webmaster
104 Major flooding inside the levees - all irrigation pumps, livestock, and equipment should be removed from inside the Rio Grande river levees below Anzalduas Dam to below Retamal Dam
99 Moderate lowland flooding will cover much of the Rio Grande river flood plain inside the levees - irrigation pumps and equipment should be removed immediately from banks below Anzalduas Dam to below Retamal Dam
95 Minor lowland flooding will exceed the Rio Grande river banks in low sections inside the levees - livestock and pumps should be removed from the lowest flood prone areas
About This Location Collapse

Latitude: 26.130556° N, Longitude: 98.336111° W, Horizontal Datum: NAD83/WGS84

River Stage
Reference Frame
Gauge Height Flood Stage Uses
NWS stage 0 ft 112 ft Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps
Vertical Datum Elevation
(gauge height = 0)
(gauge height = flood stage)
Elevation information source
NAVD88 Not Available Not Available Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps
NGVD 29 86.32 ft 198.32 ft Older USGS topographic maps, NGVD29 benchmarks
MSL Not Available Not Available Older USGS topographic maps, MSL benchmarks
Other Not Available Not Available  
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The National Weather Service prepares its forecasts and other services in collaboration with agencies like the US Geological Survey, US Bureau of Reclamation, US Army Corps of Engineers, Natural Resource Conservation Service, National Park Service, ALERT Users Group, Bureau of Indian Affairs, and many state and local emergency managers across the country. For details, please click here.
NWS Information
National Weather Service
Brownsville Weather Forecast Office
20 South Vermillion Road
Brownsville, TX 78521
(956) 504-1432
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Page last modified: 2-Nov-2020 7:29 PM
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