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Water-Year Summary for Site 12116060

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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.
  • 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
00065 Gage height(Ins.) [SEATTLE CITY LIGHT (OBSERVED)]  

Water year 2022: 2022-10-01 to 2023-09-30

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USGS Water-Year Summary 2022
LOCATION - Lat 47°24'43", long 121°45'04" referenced to North American Datum of 1927, in NE 1/4 NW 1/4 sec.11, T.22 N., R.8 E., King County, WA, Hydrologic Unit 17110012, at Masonry Dam, 1.6 mi southeast of town of Cedar Falls, and at mile 35.6.
DRAINAGE AREA - 78.4 mi².
PERIOD OF RECORD - October 1977 to current year.
GAGE - Non-recording gage 1977 to 2018. Recording gage 2018 to current year. Datum of gage is 11.43 ft above NAVD of 1988 (levels by USGS 2019) and 7.39 ft above NGVD of 1929 (levels by City of Seattle).
COOPERATION - City of Seattle Water Department, Seattle City Lights, City of North Bend.
REMARKS - Reservoir is formed by masonry gravity dam. Usable capacity, 40,285 acre-ft between gage heights 1,530.0 ft, normal minimum regulating pool, and 1,554.6 ft, normal maximum regulating pool. Unused storage below gage height 1,530.0 ft, 36,000 acre-ft. Water is used by City of Seattle for municipal water supply and power production.
EXTREMES FOR PERIOD OF RECORD - Maximum gage height observed, 1,568.53 ft, Nov. 25, 1990; minimum not determined (occurred during period Aug. 2 to Sept. 19, 1978, while the pool was drained for maintenance).