USGS Water-Year Summary for Site 12147600

Click to hide Water-Year Summary instructions and information

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.
For water years 2005 and earlier, Annual Water Data Reports may be available in digital format.
Not all sites have reports available for every water year.

	Available Parameters
	00010 Temperature, water(Max.,Min.,Mean)
	00060 Discharge(Mean)
	00065 Gage height(Mean)
	63680 Turbidity, Form Neph(Max.,Min.,Med.)

Select a water year

Water year 2024: 2024-10-01 to 2025-09-30

Print this page

USGS Water-Year Summary 2024

12147600 SOUTH FORK TOLT RIVER NEAR INDEX, WA

LOCATION - Lat 47°42'25", long 121°35'56" referenced to North American Datum of 1927, in NE 1/4 SW 1/4 sec.25, T.26 N., R.9 E., King County, WA, Hydrologic Unit 17110010, on left bank 0.6 mi upstream from Phelps Creek, 8.1 mi south of Index, and at mile 12.9.

DRAINAGE AREA - 5.34 mi².

REVISIONS HISTORY - WDR WA-02-1: 1999-2000(P).

SURFACE-WATER RECORDS

PERIOD OF RECORD - December 1959 to December 1963, November 1967 to current year.

GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 1,838.77 ft above NAVD of 1988 (USGS GNSS II, Oct. 21, 2021). Prior to Oct. 1, 1961, at datum 0.85 ft higher. Oct. 1, 1961, to Sept. 30, 1992, at datum 1.00 ft higher.

REMARKS - No regulation or diversion upstream from station. A portion of flow is within the gravel streambed and is unmeasurable. U.S. Geological Survey satellite telemeter at station.

EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 2,240 ft³/s, Dec. 15, 1999; gage height, 4.54 ft, possible result from debris dam break up; maximum gage height, 8.13 ft, present datum, Dec. 14, 1959; minimum daily discharge, 1.65 ft³/s, Oct. 16-17, 2022.

WATER-QUALITY RECORDS

PERIOD OF DAILY RECORD - Water-temperature: October 1994 to current year. Turbidity (FNU): December 2019 to current year.

INSTRUMENTATION - Water Temperature recorder and an FTS DTS-12 turbidity sensor interfaced with a Data Collection Platform/Electronic Datalogger, with 15-minute recording interval. 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 - U.S. Geological Survey satellite telemeter at station.

EXTREMES FOR PERIOD OF RECORD - Water-temperature: Maximum, 18.9°C, July 2-3, 2015; minimum recorded, 0.0°C, at times during most winter periods. Turbidity: Maximum, 317 FNU, Feb. 01, 2020; Minimum, 0.0 FNU, many days, most years.