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San Juan Radar Outage Impacts Precipitation Estimates.. read more here
Hydrograph River at a Glance Download
Rio Grande De Loiza at HWY 183 Stage (ft)Flow (kcfs)Observed: 8.36 ft at 6:30AM May 02, 2024Observed: 8.4 ft at 6:45AM May 02, 2024Observed: 8.42 ft at 7:00AM May 02, 2024Observed: 8.44 ft at 7:15AM May 02, 2024Observed: 8.47 ft at 7:30AM May 02, 2024Observed: 8.49 ft at 7:45AM May 02, 2024Observed: 8.5 ft at 8:00AM May 02, 2024Observed: 8.53 ft at 8:15AM May 02, 2024Observed: 8.61 ft at 8:30AM May 02, 2024Observed: 8.7 ft at 8:45AM May 02, 2024Highest Observation: 8.76 ft at 9:00AM May 02, 2024Highest Observation: 8.76 ft at 9:15AM May 02, 2024Observed: 8.74 ft at 9:30AM May 02, 2024Observed: 8.72 ft at 9:45AM May 02, 2024Observed: 8.69 ft at 10:00AM May 02, 2024Observed: 8.67 ft at 10:15AM May 02, 2024Observed: 8.64 ft at 10:30AM May 02, 2024Observed: 8.62 ft at 10:45AM May 02, 2024Observed: 8.59 ft at 11:00AM May 02, 2024Observed: 8.59 ft at 11:01AM May 02, 2024Observed: 8.55 ft at 11:15AM May 02, 2024Observed: 8.53 ft at 11:30AM May 02, 2024Observed: 8.5 ft at 11:45AM May 02, 2024Observed: 8.48 ft at 12:00PM May 02, 2024Observed: 8.47 ft at 12:15PM May 02, 2024Observed: 8.44 ft at 12:30PM May 02, 2024Observed: 8.42 ft at 12:45PM May 02, 2024Observed: 8.42 ft at 1:00PM May 02, 2024Observed: 8.4 ft at 1:15PM May 02, 2024Observed: 8.39 ft at 1:30PM May 02, 2024Observed: 8.38 ft at 1:45PM May 02, 2024Observed: 8.37 ft at 2:00PM May 02, 2024Observed: 8.36 ft at 2:15PM May 02, 2024Observed: 8.34 ft at 2:30PM May 02, 2024Observed: 8.32 ft at 2:45PM May 02, 2024Observed: 8.32 ft at 3:00PM May 02, 2024Observed: 8.31 ft at 3:15PM May 02, 2024Observed: 8.31 ft at 3:30PM May 02, 2024Observed: 8.29 ft at 3:45PM May 02, 2024Observed: 8.28 ft at 4:00PM May 02, 2024Observed: 8.28 ft at 4:15PM May 02, 2024Observed: 8.27 ft at 4:30PM May 02, 2024Observed: 8.26 ft at 4:45PM May 02, 2024Observed: 8.26 ft at 5:00PM May 02, 2024Observed: 8.25 ft at 5:15PM May 02, 2024Observed: 8.26 ft at 5:30PM May 02, 2024Observed: 8.26 ft at 5:45PM May 02, 2024Observed: 8.26 ft at 6:00PM May 02, 2024Observed: 8.27 ft at 6:15PM May 02, 2024Observed: 8.29 ft at 6:30PM May 02, 2024Observed: 8.29 ft at 6:45PM May 02, 2024Observed: 8.31 ft at 7:00PM May 02, 2024Observed: 8.31 ft at 7:15PM May 02, 2024Observed: 8.33 ft at 7:30PM May 02, 2024Observed: 8.33 ft at 7:45PM May 02, 2024Observed: 8.42 ft at 8:00PM May 02, 2024Observed: 8.57 ft at 8:15PM May 02, 2024Observed: 8.65 ft at 8:30PM May 02, 2024Observed: 8.62 ft at 8:45PM May 02, 2024Observed: 8.61 ft at 9:00PM May 02, 2024Observed: 8.6 ft at 9:15PM May 02, 2024Observed: 8.58 ft at 9:30PM May 02, 2024Observed: 8.55 ft at 9:45PM May 02, 2024Observed: 8.53 ft at 10:00PM May 02, 2024Observed: 8.51 ft at 10:15PM May 02, 2024Observed: 8.48 ft at 10:30PM May 02, 2024Observed: 8.45 ft at 10:45PM May 02, 2024Observed: 8.43 ft at 11:00PM May 02, 2024Observed: 8.4 ft at 11:15PM May 02, 2024Observed: 8.38 ft at 11:30PM May 02, 2024Observed: 8.37 ft at 11:45PM May 02, 2024Observed: 8.34 ft at 12:00AM May 03, 2024Observed: 8.33 ft at 12:15AM May 03, 2024Observed: 8.32 ft at 12:30AM May 03, 2024Observed: 8.3 ft at 12:45AM May 03, 2024Observed: 8.29 ft at 1:00AM May 03, 2024Observed: 8.29 ft at 1:15AM May 03, 2024Observed: 8.28 ft at 1:30AM May 03, 2024Observed: 8.28 ft at 1:45AM May 03, 2024Observed: 8.27 ft at 2:00AM May 03, 2024Observed: 8.26 ft at 2:15AM May 03, 2024Observed: 8.25 ft at 2:30AM May 03, 2024Observed: 8.24 ft at 2:45AM May 03, 2024Observed: 8.23 ft at 3:00AM May 03, 2024Observed: 8.23 ft at 3:06AM May 03, 2024Observed: 8.22 ft at 3:15AM May 03, 2024Observed: 8.21 ft at 3:30AM May 03, 2024Observed: 8.22 ft at 3:45AM May 03, 2024Observed: 8.21 ft at 4:00AM May 03, 2024Observed: 8.2 ft at 4:15AM May 03, 2024Observed: 8.19 ft at 4:30AM May 03, 2024Observed: 8.18 ft at 4:45AM May 03, 2024Observed: 8.18 ft at 5:00AM May 03, 2024Observed: 8.17 ft at 5:15AM May 03, 2024Observed: 8.16 ft at 5:30AM May 03, 2024Observed: 8.16 ft at 5:45AM May 03, 2024Observed: 8.16 ft at 6:00AM May 03, 2024Observed: 8.17 ft at 6:15AM May 03, 2024Observed: 8.18 ft at 6:30AM May 03, 2024Observed: 8.19 ft at 6:45AM May 03, 2024Observed: 8.19 ft at 7:00AM May 03, 2024Observed: 8.19 ft at 7:15AM May 03, 2024Observed: 8.17 ft at 7:30AM May 03, 2024Observed: 8.16 ft at 7:45AM May 03, 2024Observed: 8.15 ft at 8:00AM May 03, 2024Observed: 8.14 ft at 8:15AM May 03, 2024Observed: 8.13 ft at 8:30AM May 03, 2024Observed: 8.12 ft at 8:45AM May 03, 2024Observed: 8.12 ft at 9:00AM May 03, 2024Observed: 8.11 ft at 9:15AM May 03, 2024Observed: 8.11 ft at 9:30AM May 03, 2024Observed: 8.1 ft at 9:45AM May 03, 2024Observed: 8.11 ft at 10:00AM May 03, 2024Observed: 8.13 ft at 10:15AM May 03, 2024Observed: 8.17 ft at 10:30AM May 03, 2024Observed: 8.21 ft at 10:45AM May 03, 2024Observed: 8.23 ft at 11:00AM May 03, 2024Observed: 8.23 ft at 11:07AM May 03, 2024Observed: 8.22 ft at 11:15AM May 03, 2024Observed: 8.21 ft at 11:30AM May 03, 2024Observed: 8.21 ft at 11:45AM May 03, 2024Observed: 8.2 ft at 12:00PM May 03, 2024Observed: 8.2 ft at 12:15PM May 03, 2024Observed: 8.19 ft at 12:30PM May 03, 2024Observed: 8.19 ft at 12:45PM May 03, 2024Observed: 8.18 ft at 1:00PM May 03, 2024Observed: 8.17 ft at 1:15PM May 03, 2024Observed: 8.16 ft at 1:30PM May 03, 2024Observed: 8.17 ft at 1:45PM May 03, 2024Observed: 8.19 ft at 2:00PM May 03, 2024Observed: 8.19 ft at 2:15PM May 03, 2024Observed: 8.19 ft at 2:30PM May 03, 2024Observed: 8.17 ft at 2:45PM May 03, 2024Observed: 8.16 ft at 3:00PM May 03, 2024Observed: 8.15 ft at 3:15PM May 03, 2024Observed: 8.13 ft at 3:30PM May 03, 2024Observed: 8.12 ft at 3:45PM May 03, 2024Observed: 8.11 ft at 4:00PM May 03, 2024Observed: 8.1 ft at 4:15PM May 03, 2024Observed: 8.1 ft at 4:30PM May 03, 2024Observed: 8.08 ft at 4:45PM May 03, 2024Observed: 8.08 ft at 5:00PM May 03, 2024Observed: 8.07 ft at 5:15PM May 03, 2024Observed: 8.07 ft at 5:30PM May 03, 2024Observed: 8.06 ft at 5:45PM May 03, 2024Observed: 8.06 ft at 6:00PM May 03, 2024Observed: 8.07 ft at 6:15PM May 03, 2024Observed: 8.08 ft at 6:30PM May 03, 2024Observed: 8.09 ft at 6:45PM May 03, 2024Observed: 8.1 ft at 7:00PM May 03, 2024Observed: 8.12 ft at 7:15PM May 03, 2024Observed: 8.13 ft at 7:30PM May 03, 2024Observed: 8.14 ft at 7:45PM May 03, 2024Observed: 8.16 ft at 8:00PM May 03, 2024Observed: 8.19 ft at 8:15PM May 03, 2024Observed: 8.22 ft at 8:30PM May 03, 2024Observed: 8.29 ft at 8:45PM May 03, 2024Observed: 8.35 ft at 9:00PM May 03, 2024Observed: 8.4 ft at 9:15PM May 03, 2024Observed: 8.44 ft at 9:30PM May 03, 2024Observed: 8.46 ft at 9:45PM May 03, 2024Observed: 8.46 ft at 10:00PM May 03, 2024Observed: 8.46 ft at 10:15PM May 03, 2024Observed: 8.47 ft at 10:30PM May 03, 2024Observed: 8.46 ft at 10:45PM May 03, 2024Observed: 8.48 ft at 11:00PM May 03, 2024Observed: 8.48 ft at 11:15PM May 03, 2024Observed: 8.48 ft at 11:30PM May 03, 2024Observed: 8.46 ft at 11:45PM May 03, 2024Observed: 8.47 ft at 12:00AM May 04, 2024Observed: 8.44 ft at 12:15AM May 04, 2024Observed: 8.43 ft at 12:30AM May 04, 2024Observed: 8.43 ft at 12:45AM May 04, 2024Observed: 8.4 ft at 1:00AM May 04, 2024Observed: 8.39 ft at 1:15AM May 04, 2024Observed: 8.37 ft at 1:30AM May 04, 2024Observed: 8.35 ft at 1:45AM May 04, 2024Observed: 8.34 ft at 2:00AM May 04, 2024Observed: 8.33 ft at 2:15AM May 04, 2024Observed: 8.32 ft at 2:30AM May 04, 2024Observed: 8.31 ft at 2:45AM May 04, 2024Observed: 8.3 ft at 3:00AM May 04, 2024Observed: 8.3 ft at 3:11AM May 04, 2024Observed: 8.29 ft at 3:15AM May 04, 2024Observed: 8.28 ft at 3:30AM May 04, 2024Observed: 8.28 ft at 3:45AM May 04, 2024Observed: 8.27 ft at 4:00AM May 04, 2024Observed: 8.26 ft at 4:15AM May 04, 2024Observed: 8.26 ft at 4:30AM May 04, 2024Observed: 8.25 ft at 4:45AM May 04, 2024Observed: 8.24 ft at 5:00AM May 04, 2024Observed: 8.23 ft at 5:15AM May 04, 2024Observed: 8.22 ft at 5:30AM May 04, 2024Observed: 8.22 ft at 5:45AM May 04, 2024Observed: 8.21 ft at 6:00AM May 04, 2024Observed: 8.2 ft at 6:15AM May 04, 2024Observed: 8.19 ft at 6:30AM May 04, 2024Observed: 8.18 ft at 6:45AM May 04, 2024Observed: 8.17 ft at 7:00AM May 04, 2024Observed: 8.16 ft at 7:15AM May 04, 2024Observed: 8.16 ft at 7:30AM May 04, 2024Observed: 8.15 ft at 7:45AM May 04, 2024Observed: 8.14 ft at 8:00AM May 04, 2024Observed: 8.13 ft at 8:15AM May 04, 2024Observed: 8.12 ft at 8:30AM May 04, 2024Observed: 8.12 ft at 8:45AM May 04, 2024Observed: 8.11 ft at 9:00AM May 04, 2024Observed: 8.11 ft at 9:15AM May 04, 2024Observed: 8.1 ft at 9:30AM May 04, 2024Observed: 8.09 ft at 9:45AM May 04, 2024Observed: 8.09 ft at 10:00AM May 04, 2024Observed: 8.08 ft at 10:15AM May 04, 2024Observed: 8.08 ft at 10:30AM May 04, 2024Observed: 8.08 ft at 10:45AM May 04, 2024Observed: 8.07 ft at 11:00AM May 04, 2024Observed: 8.07 ft at 11:15AM May 04, 2024Observed: 8.06 ft at 11:30AM May 04, 2024Observed: 8.07 ft at 11:45AM May 04, 2024Observed: 8.07 ft at 12:00PM May 04, 2024Observed: 8.06 ft at 12:15PM May 04, 2024Observed: 8.05 ft at 12:30PM May 04, 2024Observed: 8.04 ft at 12:45PM May 04, 2024Observed: 8.04 ft at 1:00PM May 04, 2024Observed: 8.03 ft at 1:15PM May 04, 2024Observed: 8.03 ft at 1:30PM May 04, 2024Observed: 8.03 ft at 1:45PM May 04, 2024Observed: 8.02 ft at 2:00PM May 04, 2024Observed: 8.02 ft at 2:15PM May 04, 2024Observed: 8.01 ft at 2:30PM May 04, 2024Observed: 8.01 ft at 2:45PM May 04, 2024Observed: 8 ft at 3:00PM May 04, 2024Observed: 8 ft at 3:15PM May 04, 2024Observed: 7.99 ft at 3:30PM May 04, 2024Observed: 7.99 ft at 3:45PM May 04, 2024Observed: 7.99 ft at 4:00PM May 04, 2024Observed: 7.99 ft at 4:15PM May 04, 2024Observed: 7.98 ft at 4:30PM May 04, 2024Observed: 7.98 ft at 4:45PM May 04, 2024Observed: 7.97 ft at 5:00PM May 04, 2024Observed: 7.96 ft at 5:15PM May 04, 2024Observed: 7.96 ft at 5:30PM May 04, 2024Observed: 7.96 ft at 5:45PM May 04, 2024Observed: 7.96 ft at 6:00PM May 04, 2024Observed: 7.95 ft at 6:15PM May 04, 2024Observed: 7.95 ft at 6:30PM May 04, 2024Observed: 7.94 ft at 6:45PM May 04, 2024Observed: 7.94 ft at 7:00PM May 04, 2024Observed: 7.93 ft at 7:12PM May 04, 2024Observed: 7.94 ft at 7:15PM May 04, 2024Observed: 7.93 ft at 7:30PM May 04, 2024Observed: 7.93 ft at 7:45PM May 04, 2024Observed: 7.92 ft at 8:00PM May 04, 2024Observed: 7.92 ft at 8:15PM May 04, 2024Observed: 7.92 ft at 8:30PM May 04, 2024Observed: 7.91 ft at 8:45PM May 04, 2024Observed: 7.91 ft at 9:00PM May 04, 2024Observed: 7.91 ft at 9:15PM May 04, 2024Observed: 7.91 ft at 9:30PM May 04, 2024Observed: 7.91 ft at 9:45PM May 04, 2024Observed: 7.91 ft at 10:00PM May 04, 2024Observed: 7.91 ft at 10:15PM May 04, 2024Observed: 7.91 ft at 10:30PM May 04, 2024Observed: 7.91 ft at 10:45PM May 04, 2024Observed: 7.91 ft at 11:00PM May 04, 2024Observed: 7.91 ft at 11:15PM May 04, 2024Observed: 7.9 ft at 11:30PM May 04, 2024Observed: 7.9 ft at 11:45PM May 04, 2024Observed: 7.9 ft at 12:00AM May 05, 2024Observed: 7.9 ft at 12:15AM May 05, 2024Observed: 7.9 ft at 12:30AM May 05, 2024Observed: 7.9 ft at 12:45AM May 05, 2024Observed: 7.89 ft at 1:00AM May 05, 2024Observed: 7.89 ft at 1:15AM May 05, 2024Observed: 7.89 ft at 1:30AM May 05, 2024Observed: 7.88 ft at 1:45AM May 05, 2024Observed: 7.88 ft at 2:00AM May 05, 2024Observed: 7.88 ft at 2:15AM May 05, 2024Observed: 7.88 ft at 2:30AM May 05, 2024Observed: 7.88 ft at 2:45AM May 05, 2024Observed: 7.88 ft at 3:00AM May 05, 2024Observed: 7.88 ft at 3:15AM May 05, 2024Observed: 7.88 ft at 3:16AM May 05, 2024Observed: 7.88 ft at 3:30AM May 05, 2024Observed: 7.88 ft at 3:45AM May 05, 2024Observed: 7.87 ft at 4:00AM May 05, 2024Observed: 7.88 ft at 4:15AM May 05, 2024Observed: 7.88 ft at 4:30AM May 05, 2024Observed: 7.87 ft at 4:45AM May 05, 2024Observed: 7.88 ft at 5:00AM May 05, 2024Observed: 7.87 ft at 5:15AM May 05, 2024USGS--Water Resources of the United StatesSLNP4(plotting HGIRG) Graph Created (6:23AM May 5, 2024)ObservedLatest observed value: 7.87 ft at 5:15 AM AST 5-May-2024. Flood Stage is 14 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 Grande De Loiza at HWY 183. Only observed stages are available for this point.
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Downstream Gauge Downstream Gauge - at Caguas
Flood Categories (in feet)
Major Flood Stage: 28
Moderate Flood Stage: 21
Flood Stage: 14
Action Stage: 11
Low Stage (in feet): -9999

Historic Crests
(1) 35.62 ft on 09/10/1996
(2) 31.37 ft on 01/05/1992
(3) 30.14 ft on 09/21/1998
(4) 26.74 ft on 09/15/2004
(5) 24.55 ft on 04/29/2019 (P)
Show More Historic Crests

(P): Preliminary values subject to further review.

Recent Crests
(1) 18.07 ft on 04/08/2023 (P)
(2) 14.65 ft on 11/15/2022 (P)
(3) 16.59 ft on 11/07/2022 (P)
(4) 14.96 ft on 10/27/2022 (P)
(5) 19.78 ft on 09/18/2022 (P)
Show More Recent Crests

(P): Preliminary values subject to further review.

Low Water Records
(1) 12.93 ft on 08/24/1997
Zoom Level:14
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
18 La Marina bridge PR 980 likely to be impassable. oms 3/2023
16 Road 181 near Escuela Vocacional Dr. Antonio Fernos Isern flooded. OMS 4/2023
14 Rio Loiza out of its banks along road 183./OMS 2/2022
About This Location Collapse

Latitude: 18.183719° N, Longitude: 65.961055° W, Horizontal Datum: NAD27

River Stage
Reference Frame		 Gauge Height Flood Stage Uses
NWS stage 0 ft 14 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 29 263 277 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:
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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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