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Water-Year Summary for Site 14203500

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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.
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Available Parameters
00010 Temperature, water(Max.,Min.,Mean)  
00060 Discharge(Mean)  
00095 Specific cond at 25C(Max.,Min.,Mean)  
00300 Dissolved oxygen(Max.,Min.,Mean)  
00400 pH(Med.,Max.,Min.)  
32295 fDOM, water, in situ(Min.,Max.,Mean)  
32315 Relative fChl, water, in situ(Max.,Min.,Mean)  
32316 fChl, water, in situ(Mean,Max.,Min.)  
32319 fPC, water, in situ(Min.,Mean,Max.)  
32321 Relative fPC, water, in situ(Max.,Min.,Mean)  
63680 Turbidity, Form Neph(Max.,Med.,Min.)  

Water year 2024: 2024-10-01 to 2025-09-30
 
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USGS Water-Year Summary 2024
14203500 TUALATIN RIVER NEAR DILLEY, OR
LOCATION - Lat 45°28'30", long 123°07'23" referenced to North American Datum of 1927, in NE 1/4 NW 1/4 sec.24, T.1 S., R.4 W., Washington County, OR, Hydrologic Unit 17090010, on right bank, 5 ft upstream from highway bridge, 1.0 mi south of Dilley, 1.2 mi downstream from Scoggins Creek and at mile 58.8.
DRAINAGE AREA - 125 mi².
REVISIONS HISTORY - WSP 1935: Drainage area.
SURFACE-WATER RECORDS
PERIOD OF RECORD - October 1939 to current year.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 147.57 ft above NGVD of 1929. Prior to June 16, 1950, nonrecording gage at several sites within 200 ft of present site at datum 4.00 ft higher. June 16, 1950 to Aug. 10, 1966, water-stage recorder at present site at datum 4.00 ft higher.
REMARKS - Diurnal fluctuation caused by operation of millpond on Scoggins Creek upstream. Flow regulated since January 1975 by Henry Hagg Lake (active capacity, 56,160 acre-ft). Diversion upstream from station from J.W. Barney Reservoir (capacity, 20,000 acre-ft) on Middle Fork of North Fork of Trask River for industrial use and pollution abatement.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 17,100 ft³/s Dec. 22, 1964, gage height, 19.34 ft, present datum, from rating curve extended above 6,000 ft³/s; minimum discharge, 0.08 ft³/s Sept. 3, 1967.
WATER-QUALITY RECORDS
PERIOD OF RECORD -

SPECIFIC CONDUCTANCE: March 2016 to current year.

pH: March 2016 to current year.

WATER TEMPERATURE: March 2016 to current year.

DISSOLVED OXYGEN: February 2020 to current year.

TURBIDITY: March 2016 to current year.

INSTRUMENTATION - Water-quality monitor. Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.
REMARKS - TURBIDITY: Data collected using a YSI EXO2 sonde. Manufacturer's stated accuracy is the greater of +/- 2 percent of reading or 0.3 Formazin Nephelometric Units (FNU) for 0-999 FNU, and +/- 5 percent for 1,000-4,000 FNU. FNU values below 10 are reported to nearest 0.1 FNU. Negative recorded values are reported as 0.0 FNU. Chemical analyses and periodic suspended sediment data collected at this location are available via NWISWeb. Additional parameters collected at this location are available via NWISWeb.
EXTREMES FOR PERIOD OF DAILY RECORD -

SPECIFIC CONDUCTANCE: Maximum, 109 microsiemens June 6, 2022; minimum, 41 microsiemens Jan. 19, 2017.

pH: Maximum, 7.6 units June 13-15, 2018; minimum, 6.5 units Dec. 28, 29, 2022.

WATER TEMPERATURE: Maximum, 18.9°C July 7, 2016; minimum, 0.6°C Feb. 24, 2023.

DISSOLVED OXYGEN: Maximum, 13.6 mg/L Dec. 23, 2022; minimum, 8.2 mg/L May 18, Sept. 22, 2023.

TURBIDITY: Maximum, 215 FNU Feb. 12, 2019; minimum, 1.2 FNU Oct. 21, 2021.