USGS Water-Year Summary 2020
12143800 RATTLESNAKE LAKE AT CEDAR FALLS, WA
LOCATION - Lat 47°25'39", long 121°46'29" referenced to North American Datum of 1927, in SW 1/4 SW 1/4 sec.34, T.23 N., R.8 E., King County, WA, Hydrologic Unit 17110010, on southeast shore, and 0.6 mi northeast of town of Cedar Falls.
DRAINAGE AREA - 1.86 mi².
PERIOD OF RECORD - November to December 1945 (fragmentary), January 1953 to current year. Extremes prior to October 1960 published in WSP 1932 and daily gage heights are available in files of the U.S. Geological Survey.
GAGE - Nonrecording gage. Datum of gage is 7.25 ft above NGVD of 1929 (levels by City of Seattle).
COOPERATION - Gage readings furnished by City of Seattle Water Department.
EXTREMES FOR PERIOD OF RECORD - Maximum gage height observed, 911.80 ft, Nov. 25, 26, 1959; minimum observed, 852.80 ft, Jan. 9, 1953, but may have been less during Dec. 13, 1965, to Jan. 3, 1966, and Nov. 10 to Dec. 23, 1970, when water was below gage.