LOCATION.--Lat 47° 39'58", long 116° 46'14"
(NAD83), in NE1/4 NW1/4 SE1/4 sec.24, T.50 N., R.4 W., Kootenai
County, Coeur d'Alene quad., Hydrologic Unit 17010303, 500 ft
southwest of south end of Eleventh Street in Coeur d'Alene, and
113.1 mi upstream from mouth of Spokane River.
DRAINAGE AREA.--3,700 mi2, approximately.
PERIOD OF RECORD.--April 1903 to current year.
REMARKS.--Gage height is referenced to an arbitrary datum of
2,100.00 ft (see HISTORY section and WSP 882). Add 2,100.81 ft to
gage height values to obtain water surface elevations referenced to
NAVD of 1988. Add 2,097.00 ft to gage height values to obtain water
surface elevations referenced to NGVD of 1929. Avista Utilities
stores water in Coeur d'Alene Lake by regulation at Post Falls
Dam for power generation at Post Falls and other plants on Spokane
River. Storage is within natural range of lake stage. Contents given
herein are those above elevation 2,120.0 ft. Capacity of lake between
elevations 2,120 ft and 2,140 ft, 889,000 acre-ft.
HISTORY.--The arbitrary datum of 2,100.00 ft is referenced to the
originally accepted elevation of U.S. Geological Survey bench mark in
southeast corner of Idaho First National Bank Building (see WSP 882),
elevation 2,157.40 ft. Datum of gage based on NGVD of 1929, with a
supplementary adjustment of 1947, is 2,097.00 ft. Datum conversion
from NGVD of 1929 to NAVD of 1988 is based on a GPS survey by Spokane
County Engineers in October 2004.
Apr. 26, 1903 to Feb. 14, 1905, non-recording gage at mouth of St.
Joe River was at datum about 18.7 ft higher than arbitrary gage
datum. Feb. 15, 1905 to Mar. 23, 1921, non-recording gage, and Mar.
24, 1921 to Dec. 22, 1930, water-stage recorder at Johnson Wharf 800
ft southeast of railroad station and 1 mi northwest of present site
at datum 19.75 ft higher than arbitrary gage datum. Dec. 23, 1930 to
Feb. 9, 1931, non-recording gage at present site and datum. Concrete
stilling well gage adjacent to Tubbs Hill provided record Feb. 10,
1931 to Jan. 23, 2008. Present gage installed on Jan. 24, 2008 at
Eleventh Street Marina.
EXTREMES FOR PERIOD OF RECORD.--Maximum contents, 834,900 acre-ft
Dec. 25, 1933, elevation, 2,139.05 ft; minimum, 2,700 acre-ft below
zero of contents table Oct. 10-12, 1904, Sept. 24, 25, 1905, Oct. 14
to Nov. 3, 1906, Feb. 9, 10, 1977, elevation, 2,119.9 ft.
EXTREMES OUTSIDE PERIOD OF RECORD.--Maximum contents known prior
to 1903, 753,300 acre-ft May 31, 1894, elevation, 2,137.6 ft, from