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NOCA42 TJSJ 211921
PNSSJU
PRZ009-010-220730-

Public Information Statement
National Weather Service San Juan PR
321 PM AST Wed May 21 2025

TO: Subscribers: Emergency Management OfficialsNews Mediaand Other Users

SUBJECT: Changes in action and flood stage categories for Rio Grande de
Anasco nr San Sebastian (SEBP4)

The National Weather Service (NWS), Weather Forecast Office in San Juan
will change the current action, minor flood and moderate flood stages for
Rio Grande de Anasco nr San Sebastian (NWSLI SEBP4 or USGS ID 50144000)
forecast point effective on August 5th, 2025. In order to better serve our
customers, the NWS communicated with the Municipal Office of Emergency
Manager (OMME, in Spanish) to determine at which levels the municipality of
Anasco takes action to protect the lives of their residents.

By definition, Action Stage is the level which, when reached by a rising
stream, represents the level where the NWS or a customer/partner needs to
take some type of mitigation action in preparation for possible significant
hydrologic activity. OMME would make preventive evacuations of some
communities when the river reaches 11 ft.

Minor flood is defined as minimal or no property damage, but possibly some
public threat. At 12.5 ft, the river will flood some agricultural
terrains.

Additionally, Moderate flood is defined as some inundation of structures
and roads near a stream. At 15.5, the river affects several residences
along Barrio Cidra and Barrio Espino, and at 17 feet, flood water will also
reach the houses in Sector Pagan, Sector Pozo Hondo, Barrio Playa. Also,
road PR-2 will become impassable.

With these arguments in mind, the flood stages will change from

 Action Stage currently begins at 7.0 ft changing to 11.0 ft
 Minor Flood currently begins at 11.0 ft changing to 12.5 ft
 Moderate Flood currently begins at 14.0 ft changing to 15.5 ft

No changes will be made to the Major flood stage, currently set at 19 ft.

In compliance with NWSI Directive 10-1805, there will be a 75-day public
comment period ending on Tuesday, August 5th, 2025, when the new criteria
will take effect. If you have any questions or concerns, please contact our
Senior Service Hydrologist, Emanuel Rodriguez, at
emanuel.rodriguez@noaa.gov.

NWS SJU, Southeast River Forecast Center, and OMME approved these changes.

The data for this site can be found at: https://water.noaa.gov/gauges/SEBP4

The data for this site would not be possible without the support and
services provided by our partners in the U.S. Geological Survey. The data
for the USGS site can be found here: https://waterdata.usgs.gov/monitoring-
location/50144000/#dataTypeId=continuous-00065-0&period=P7D



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