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- Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
- For water years 2014 onward, choose a water year and parameter and an on-demand Water-Year Summary report will be generated.
- For water years 2006 through 2013, choose a water year and an Annual Water Data Report will be provided.
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USGS Water-Year Summary 2024
12013500 WILLAPA RIVER NEAR WILLAPA, WA
LOCATION - Lat 46°39'04", long 123°39'05" referenced to North American Datum of 1927, in SW 1/4 SW 1/4 sec.35, T.14 N., R.8 W., Pacific County, WA, Hydrologic Unit 17100106, on upstream side of Camp 1 Road bridge, 4,500 ft downstream from Mill Creek, 1.8 mi southeast of Willapa, and at mile 17.4.
DRAINAGE AREA - 130 mi².
SURFACE-WATER RECORDS
PERIOD OF RECORD - August to October 1947, July 1948 to December 1954, water years 1955-56, 1958-59 (annual maximum), April 1961 to current year.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 6.92 ft above NAVD of 1988 (USGS GNSS survey June 8, 2022) and 3.57 ft above NGVD of 1929. Aug. 26 to Oct. 16, 1947, water-stage recorder at site 2,060 ft upstream at different datum. July 28, 1948, to Dec. 2, 1954, water-stage recorder, water years 1955-56, 1958-59, nonrecording gage, and Apr. 1, 1961, to Apr. 14, 1974, water-stage recorder at site 2,000 ft upstream at datum 2.12 ft higher. Apr. 15, 1974 to July 31, 2013, water stage recorder at site 250 ft upstream at same datum.
REMARKS - Some diversion for domestic use and irrigation upstream from station. No regulation. Some discharges are affected by extreme high tides. U.S. Geological Survey satellite telemeter at station. Chemical analyses October 1965 to September 1986.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 15,100 ft³/s, Dec. 03, 2007. Maximum gage height, 27.28 ft, Dec. 20, 1994, minimum daily mean discharge, 9.52 ft³/s, Aug. 22, 2023.
