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USGS Water-Year Summary 2024
14169000 LONG TOM RIVER NEAR ALVADORE, OR
LOCATION - Lat 44°07'25", long 123°17'55" referenced to North American Datum of 1927, in SW 1/4 NE 1/4 sec.04, T.17 S., R.5 W., Lane County, OR, Hydrologic Unit 17090003, on left bank, 0.2 mi downstream from Fern Ridge Dam, 1.7 mi west of Alvadore and at mile 25.5.
DRAINAGE AREA - 252 mi². not including Amazon Creek basin.
REVISIONS HISTORY - WSP 1248: 1940-41, 1948. WDR-US-2010: 1999(M), 2000(M).
SURFACE-WATER RECORDS
PERIOD OF RECORD - August 1939 to current year. Prior to October 1943, published as "at Smithfield" and October 1943 to September 1959, as "below Fern Ridge Dam, near Smithfield." Prior to October 1985, published figures included diversion from Fern Ridge Reservoir into Coyote Creek channel (station 14169001).
GAGE - Water-stage recorder, crest-stage gage, and masonry control. Datum of gage is 335.56 ft above NAVD of 1988 determined by GNSS Level II survey. Prior to Sept. 21, 1939, nonrecording gage and Sept. 21, 1939, to Sept. 30, 1943, water-stage recorder at site 2.5 mi downstream at datum 11.09 ft lower.
REMARKS - Flow regulated since 1941 by Fern Ridge Lake (active capacity, 93,350 acre-ft). Several diversions for irrigation upstream from station. Discharge not adjusted for storage or release from Fern Ridge Lake as evaporation from reservoir at times exceeds natural flow and diversions. Beginning November 1951, most of flow of Amazon Creek has been diverted into Fern Ridge Lake. Drainage area at point of diversion, 21.3 mi².
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 11,500 ft³/s Jan. 1, 1943, gage height, 15.12 ft, site and datum then in use; minimum daily discharge, 2 ft³/s Aug. 7, 1941.
WATER-QUALITY RECORDS
PERIOD OF DAILY RECORD -
WATER TEMPERATURE: August 2001 to current year.
TURBIDITY: March 2005 to September 2006.
INSTRUMENTATION - Temperature probe and data logger.
EXTREMES FOR PERIOD OF DAILY RECORD -
WATER TEMPERATURE: Maximum, 25.4°C June 28, 29, 2021; minimum, -0.2°C Dec. 8, 2009.
TURBIDITY: Maximum recorded, >1,000 FNU on many days during July to October 2005; minimum recorded, 3.3 FNU July 4, 2006, but may have been lower during periods of missing record.
