USGS Water-Year Summary for Site 12116400

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	Available Parameters
	00010 Temperature, water(Mean,Min.,Max.)
	00020 Temperature, air(Mean,Max.,Min.)
	00060 Discharge(Mean)
	00065 Gage height(Mean)

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

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USGS Water-Year Summary 2024

12116400 CEDAR RIVER AT POWERPLANT, AT CEDAR FALLS, WA

LOCATION - Lat 47°25'08", long 121°46'49" referenced to North American Datum of 1927, in SE 1/4 sec.04, T.22 N., R.8 E., King County, WA, Hydrologic Unit 17110012, on right bank 100 ft upstream from Seattle Municipal Powerplant at town of Cedar Falls, and at mile 33.7.

DRAINAGE AREA - 83.9 mi². includes 78.4 mi² upstream from Cedar Lake which is non-contributing except during spillage and seepage from dam.

REVISIONS HISTORY -

Peaks for the Water Years 2020, 2021, 2022 and 2023 have been revised. These values, shown in the following table, supersede previously published figures.

Water Year	Date	Discharge (ft³/s)	Gage Height (ft)
2020	Feb. 7, 2020	3,705	38.15
2021	Jan. 14, 2021	1,410	35.68
2022	Nov. 16, 2021	1,203	35.38
2023	May 20, 2023	431	33.73

SURFACE-WATER RECORDS

PERIOD OF RECORD - Oct 2001 to current year.

GAGE - Water-stage recorder and concrete weir. Datum of gage is 900.00 ft above NGVD of 1929 (City of Seattle benchmark) and is 910.83 ft above NAVD of 1988 (GNSS survey by USGS, July 19, 2022).

REMARKS - Flow regulated by Chester Morse Lake (station 12115900) and Cedar Lake (station 12116060) to supply powerplant, which discharges below gage. U.S. Geological Survey satellite telemeter at station.

EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 3,740 ft³/s, Jan. 8, 2009, gage height 38.05 ft; minimum discharge, 3.0 ft³/s, Aug. 28, 2003.

WATER-QUALITY RECORDS

PERIOD OF DAILY RECORD - WATER TEMPERATURE: October 2018 to current year.

REMARKS - Additional details are available from the Washington Water Science Center. Continuous water quality record is no longer rated, as of water year 2021. Prior ratings can be obtained via request to the Washington Water Science Center.

EXTREMES FOR PERIOD OF DAILY RECORD - WATER TEMPERATURE: Maximum, 22.1°C, Aug. 17, 2023; minimum, 0.3°C, Dec. 22, 2022.