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San Juan Radar Outage Impacts Precipitation Estimates.. read more here
Hydrograph River at a Glance Download
Rio Guanajibo near Hormigueros Stage (ft)Flow (kcfs)Observed: 11.99 ft at 8:45PM May 24, 2022Observed: 12.54 ft at 9:30PM May 24, 2022Observed: 12.09 ft at 10:45PM May 24, 2022Observed: 11.85 ft at 11:15PM May 24, 2022Observed: 11.73 ft at 11:30PM May 24, 2022Observed: 11.64 ft at 11:45PM May 24, 2022Observed: 11.53 ft at 12:00AM May 25, 2022Observed: 11.43 ft at 12:15AM May 25, 2022Observed: 11.36 ft at 12:30AM May 25, 2022Observed: 11.22 ft at 1:00AM May 25, 2022Observed: 11.15 ft at 1:15AM May 25, 2022Observed: 11.12 ft at 1:30AM May 25, 2022Observed: 11.02 ft at 2:00AM May 25, 2022Observed: 10.99 ft at 2:15AM May 25, 2022Observed: 10.89 ft at 2:45AM May 25, 2022Observed: 10.88 ft at 3:00AM May 25, 2022Observed: 10.86 ft at 3:15AM May 25, 2022Observed: 10.81 ft at 3:30AM May 25, 2022Observed: 10.8 ft at 3:45AM May 25, 2022Observed: 10.74 ft at 4:00AM May 25, 2022Observed: 10.7 ft at 4:30AM May 25, 2022Observed: 10.69 ft at 4:45AM May 25, 2022Observed: 10.66 ft at 5:15AM May 25, 2022Observed: 10.62 ft at 5:30AM May 25, 2022Observed: 10.62 ft at 5:45AM May 25, 2022Observed: 10.6 ft at 6:00AM May 25, 2022Observed: 10.59 ft at 6:15AM May 25, 2022Observed: 10.57 ft at 6:30AM May 25, 2022Observed: 10.57 ft at 6:45AM May 25, 2022Observed: 10.56 ft at 7:15AM May 25, 2022Observed: 10.56 ft at 7:30AM May 25, 2022Observed: 10.53 ft at 8:15AM May 25, 2022Observed: 10.52 ft at 8:30AM May 25, 2022Observed: 10.51 ft at 8:45AM May 25, 2022Observed: 10.5 ft at 9:00AM May 25, 2022Observed: 10.5 ft at 9:15AM May 25, 2022Observed: 10.51 ft at 9:30AM May 25, 2022Observed: 10.47 ft at 10:45AM May 25, 2022Observed: 10.46 ft at 11:00AM May 25, 2022Observed: 10.44 ft at 11:30AM May 25, 2022Observed: 10.43 ft at 11:45AM May 25, 2022Observed: 10.43 ft at 12:00PM May 25, 2022Observed: 10.44 ft at 12:15PM May 25, 2022Observed: 10.44 ft at 12:45PM May 25, 2022Observed: 10.45 ft at 1:00PM May 25, 2022Observed: 10.43 ft at 1:30PM May 25, 2022Observed: 10.44 ft at 2:15PM May 25, 2022Observed: 10.43 ft at 2:30PM May 25, 2022Observed: 10.42 ft at 2:45PM May 25, 2022Observed: 10.42 ft at 3:00PM May 25, 2022Observed: 10.42 ft at 3:15PM May 25, 2022Observed: 10.42 ft at 3:30PM May 25, 2022Observed: 10.42 ft at 3:45PM May 25, 2022Observed: 10.41 ft at 4:45PM May 25, 2022Observed: 10.44 ft at 5:00PM May 25, 2022Observed: 10.53 ft at 5:15PM May 25, 2022Observed: 10.68 ft at 5:30PM May 25, 2022Observed: 10.79 ft at 6:00PM May 25, 2022Observed: 10.8 ft at 6:15PM May 25, 2022Observed: 10.99 ft at 6:45PM May 25, 2022Observed: 11.09 ft at 7:00PM May 25, 2022Observed: 11.14 ft at 7:15PM May 25, 2022Observed: 11.16 ft at 7:30PM May 25, 2022Observed: 11.17 ft at 7:45PM May 25, 2022Observed: 11.15 ft at 8:00PM May 25, 2022Observed: 11.13 ft at 8:15PM May 25, 2022Observed: 11.39 ft at 9:45PM May 25, 2022Observed: 11.51 ft at 10:15PM May 25, 2022Observed: 11.6 ft at 10:30PM May 25, 2022Observed: 11.63 ft at 10:45PM May 25, 2022Observed: 11.67 ft at 11:15PM May 25, 2022Observed: 11.69 ft at 11:30PM May 25, 2022Observed: 11.56 ft at 12:45AM May 26, 2022Observed: 11.52 ft at 1:00AM May 26, 2022Observed: 11.52 ft at 1:15AM May 26, 2022Observed: 11.53 ft at 1:30AM May 26, 2022Observed: 11.53 ft at 2:00AM May 26, 2022Observed: 11.51 ft at 2:15AM May 26, 2022Observed: 11.46 ft at 2:45AM May 26, 2022Observed: 11.42 ft at 3:00AM May 26, 2022Observed: 11.39 ft at 3:15AM May 26, 2022Observed: 11.38 ft at 3:30AM May 26, 2022Observed: 11.33 ft at 3:45AM May 26, 2022Observed: 11.3 ft at 4:00AM May 26, 2022Observed: 11.26 ft at 4:15AM May 26, 2022Observed: 11.24 ft at 4:30AM May 26, 2022Observed: 11.2 ft at 4:45AM May 26, 2022Observed: 11.13 ft at 5:30AM May 26, 2022Observed: 11.03 ft at 6:45AM May 26, 2022Observed: 11 ft at 7:00AM May 26, 2022Observed: 11 ft at 7:15AM May 26, 2022Observed: 11 ft at 7:30AM May 26, 2022Observed: 10.98 ft at 8:00AM May 26, 2022Observed: 10.98 ft at 8:15AM May 26, 2022Observed: 10.94 ft at 8:30AM May 26, 2022Observed: 10.86 ft at 10:00AM May 26, 2022Observed: 10.86 ft at 10:15AM May 26, 2022Observed: 10.85 ft at 10:45AM May 26, 2022Observed: 10.83 ft at 11:00AM May 26, 2022Observed: 10.83 ft at 11:15AM May 26, 2022Observed: 10.82 ft at 11:30AM May 26, 2022Observed: 10.81 ft at 11:45AM May 26, 2022Observed: 10.81 ft at 12:00PM May 26, 2022Observed: 10.79 ft at 12:45PM May 26, 2022Observed: 10.77 ft at 1:00PM May 26, 2022Observed: 10.76 ft at 1:30PM May 26, 2022Observed: 10.73 ft at 2:30PM May 26, 2022Observed: 10.73 ft at 2:45PM May 26, 2022Observed: 10.73 ft at 3:00PM May 26, 2022Observed: 10.76 ft at 3:15PM May 26, 2022Observed: 10.82 ft at 3:30PM May 26, 2022Observed: 11.05 ft at 4:15PM May 26, 2022Observed: 11.12 ft at 4:30PM May 26, 2022Observed: 11.13 ft at 4:45PM May 26, 2022Observed: 11.13 ft at 5:00PM May 26, 2022Observed: 11.18 ft at 5:15PM May 26, 2022Observed: 11.26 ft at 5:30PM May 26, 2022Observed: 11.41 ft at 6:00PM May 26, 2022Observed: 11.42 ft at 6:15PM May 26, 2022Observed: 11.81 ft at 6:45PM May 26, 2022Observed: 12.45 ft at 7:00PM May 26, 2022Observed: 14.04 ft at 7:30PM May 26, 2022Observed: 14.7 ft at 7:45PM May 26, 2022Observed: 15.19 ft at 8:00PM May 26, 2022Observed: 15.5 ft at 8:15PM May 26, 2022Observed: 15.93 ft at 8:45PM May 26, 2022Highest Observation: 15.99 ft at 9:30PM May 26, 2022Observed: 15.89 ft at 9:45PM May 26, 2022Observed: 15.56 ft at 10:15PM May 26, 2022Observed: 15.34 ft at 10:30PM May 26, 2022Observed: 14.12 ft at 11:45PM May 26, 2022Observed: 13.89 ft at 12:00AM May 27, 2022Observed: 13.66 ft at 12:15AM May 27, 2022Observed: 13.49 ft at 12:30AM May 27, 2022Observed: 12.44 ft at 2:45AM May 27, 2022Observed: 12.35 ft at 3:00AM May 27, 2022Observed: 12.26 ft at 3:30AM May 27, 2022Observed: 12.2 ft at 3:45AM May 27, 2022Observed: 12.14 ft at 4:00AM May 27, 2022Observed: 12.1 ft at 4:15AM May 27, 2022Observed: 12.07 ft at 4:30AM May 27, 2022Observed: 12.04 ft at 4:45AM May 27, 2022Observed: 11.94 ft at 5:30AM May 27, 2022Observed: 11.9 ft at 5:45AM May 27, 2022Observed: 11.88 ft at 6:00AM May 27, 2022Observed: 11.86 ft at 6:15AM May 27, 2022Observed: 11.83 ft at 6:30AM May 27, 2022Observed: 11.81 ft at 6:45AM May 27, 2022Observed: 11.81 ft at 7:15AM May 27, 2022Observed: 11.78 ft at 7:30AM May 27, 2022Observed: 11.79 ft at 8:00AM May 27, 2022Observed: 11.77 ft at 8:15AM May 27, 2022Observed: 11.75 ft at 8:30AM May 27, 2022Observed: 11.72 ft at 8:45AM May 27, 2022Observed: 11.71 ft at 9:00AM May 27, 2022Observed: 11.7 ft at 9:15AM May 27, 2022Observed: 11.7 ft at 9:30AM May 27, 2022Observed: 11.66 ft at 10:00AM May 27, 2022Observed: 11.63 ft at 10:15AM May 27, 2022Observed: 11.63 ft at 10:30AM May 27, 2022Observed: 11.62 ft at 10:45AM May 27, 2022Observed: 11.59 ft at 11:00AM May 27, 2022Observed: 11.57 ft at 11:30AM May 27, 2022Observed: 11.56 ft at 11:45AM May 27, 2022Observed: 11.55 ft at 12:00PM May 27, 2022Observed: 11.53 ft at 12:15PM May 27, 2022Observed: 11.51 ft at 12:45PM May 27, 2022Observed: 11.47 ft at 1:00PM May 27, 2022Observed: 11.48 ft at 1:15PM May 27, 2022Observed: 11.48 ft at 1:30PM May 27, 2022Observed: 11.45 ft at 1:45PM May 27, 2022Observed: 11.44 ft at 2:00PM May 27, 2022Observed: 11.44 ft at 2:15PM May 27, 2022Observed: 11.41 ft at 2:30PM May 27, 2022Observed: 11.4 ft at 2:45PM May 27, 2022Observed: 11.39 ft at 3:15PM May 27, 2022Observed: 11.37 ft at 3:30PM May 27, 2022Observed: 11.36 ft at 3:45PM May 27, 2022Observed: 11.35 ft at 4:15PM May 27, 2022Observed: 11.31 ft at 4:45PM May 27, 2022Observed: 11.3 ft at 5:00PM May 27, 2022Observed: 11.32 ft at 5:15PM May 27, 2022Observed: 11.28 ft at 5:30PM May 27, 2022Observed: 11.27 ft at 6:00PM May 27, 2022Observed: 11.27 ft at 6:15PM May 27, 2022Observed: 11.26 ft at 6:30PM May 27, 2022Observed: 11.26 ft at 6:45PM May 27, 2022Observed: 11.28 ft at 7:00PM May 27, 2022Observed: 11.24 ft at 7:30PM May 27, 2022USGS--Water Resources of the United StatesHORP4(plotting HGIRG) Graph Created (8:36PM May 27, 2022)ObservedLatest observed value: 11.24 ft at 7:30 PM AST 27-May-2022. Flood Stage is 20 ft
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About this graph
Tabular Data (UTC)
Tabular Data (AST)
XML Data
RSS Files
Datum: NGVD29
Metadata
NOTE: Forecasts are not available for the Rio Guanajibo near Hormigueros. Only observed stages are available for this point.
Return to Area Map
Flood Categories (in feet)
Major Flood Stage: 26
Moderate Flood Stage: 22
Flood Stage: 20
Action Stage: 16
Low Stage (in feet): -9999

Historic Crests
(1) 28.59 ft on 09/21/2017
(2) 28.59 ft on 09/20/2017
(3) 28.50 ft on 09/16/1975
(4) 28.03 ft on 09/22/1998
(5) 28.00 ft on 10/07/1985
Show More Historic Crests

(P): Preliminary values subject to further review.

Recent Crests
(1) 25.37 ft on 08/01/2020 (P)
(2) 20.47 ft on 01/01/2020 (P)
(3) 21.85 ft on 10/27/2019 (P)
(4) 20.49 ft on 10/18/2019 (P)
(5) 20.62 ft on 10/17/2019 (P)
Show More Recent Crests

(P): Preliminary values subject to further review.

Low Water Records
(1) 12.19 ft on 10/06/1980
Zoom Level:15
KML Image
Gauge LocationGauge Map Marker
 Disclaimer
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
21 At 21 feet...the river begins to affect area homes ... residential flooding expected.
20.3 Between 20 and 22 feet ... river is out of its banks and flooding CARR #114 and CARR #347.
19 Between 19.0 and 19.5 feet...Flooding along CARR #114 and CARR #309 in Hormigueros and Mayaguez.
About This Location Collapse

Latitude: 18.140694° N, Longitude: 67.148374° W, Horizontal Datum: NAD27

River Stage
Reference Frame		 Gauge Height Flood Stage Uses
NWS stage 0 ft 20 ft Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps
Vertical Datum Elevation
(gauge height = 0)		 Elevation
(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 13 33 Older USGS topographic maps, NGVD29 benchmarks
MSL Not Available Not Available Older USGS topographic maps, MSL benchmarks
Other Not Available Not Available  

Current/Historical Observations:
Resources Collapse
Hydrologic Resources Additional Resources
Collaborative Agencies Collapse
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
San Juan Weather Forecast Office
4000 Carreterra 190
San Juan, PR 00979
(787) 253-4586
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