USGS Water-Year Summary 2021
50144000 RIO GRANDE DE ANASCO NEAR SAN SEBASTIAN, PR
LOCATION - Lat 18°17'03.00", long 67°03'03.46" referenced to North American Datum of 1927, Anasco Municipio, PR, Hydrologic Unit 21010003, on left bank, at downstream side of bridge on State Road 108, 0.4 mi (0.6 km) downstream from Quebrada La Zumbadora, 4.4 mi (7.1 km) northwest of Las Marías, and 5.4 mi (8.7 km) southwest of San Sebastián.
DRAINAGE AREA - 134 mi². (347 km2), includes 36.2 mi² (94.0 km2) which contributes only during high floods, and 3.5 mi² (9.1 km2) which contributes only part of its storm runoff, previously excluded.
WDR PR-2000-1: 1999: (M); WDR PR-2010-1: 2009: (M).
Drainage area revised in 2021 based on ArcHydro 2020, more detailed topo used.
PERIOD OF RECORD - April 1, 1963 to current year.
GAGE - Water-stage recorder and satellite telemetry at station. Datum of gage is 105.5 ft. (32.2 m) above Puerto Rico Vertical Datum of 2002 (PRVD02). Prior to October 30, 1975, at site 600 ft. (180 m) upstream, at same datum. Elevation or datum was previously reported as 164 ft. (50 m) above mean sea level and NGVD 29 and was established via topographic map and a new GNSS survey was used to establish a PRVD02 datum because the topographic datum did not meet the new accuracy requirements.
PERIOD OF RECORD - June 2018 to current year.
PERIOD OF RECORD - January 10, 1963 to current year.
INSTRUMENTATION - Tipping bucket precipitation gage and data collection platform – 15 minutes interval.