USGS Water-Year Summary 2024
05569500 SPOON RIVER AT LONDON MILLS, IL
LOCATION - Lat 40°42'27.8", long 90°16'47.2" referenced to North American Datum of 1983, in SW 1/4 NE 1/4 sec.4, T.8 N., R.2 E., Fulton County, IL, Hydrologic Unit 07130005, on downstream side of bridge on State Highway 116, 0.2 mi downstream from a railroad bridge, 0.5 mi southwest of London Mills, 0.5 mi upstream from Cedar Creek, 4.0 mi downstream from Littlers Creek, and at mile 69.2.
DRAINAGE AREA - 1,072 mi². area at site used prior to Apr. 26, 1984, 1,062 mi².
REVISIONS HISTORY -
WSP 1175: 1947. WDR IL-84-2: 1948(M), 1950(M), 1951, 1954(M), 1955,
1958, 1960, 1962, 1964, 1965, 1970, and drainage area.
On Mar. 25, 2020, statistical calculations were enabled for
mean-daily discharge and mean-daily stage for Aug. 7-9, 2018, due to missing
record.
SURFACE-WATER RECORDS
PERIOD OF RECORD -
SURFACE-WATER DISCHARGE AND STAGE
DISCHARGE: October 1942 to current.
STAGE: Water years 1994 to current.
SURFACE-WATER QUALITY
CHEMICAL: Water years 1978-91.
MISCELLANEOUS: Water years 1998 and 2002.
GAGE -
Water-stage recorder, U.S. Army Corps of Engineers satellite telemeter and crest-stage gage.
Datum of gage is 508.56 ft above North American Vertical Datum of 1988.
July 14, 1945, to Apr. 26, 1984, at site 0.9 mi upstream at same datum.
Prior to July 13, 1945, nonrecording gage at same site and datum.
EXTREMES OUTSIDE PERIOD OF RECORD -
SURFACE-WATER DISCHARGE AND STAGE:
Flood of Aug. 26, 1924, reached a stage of 27.08 ft, from information by local residents.
EXTREMES FOR PERIOD OF RECORD -
SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 41,000 ft³/s, June 23, 1974, gage height, 28.03 ft, from graph based on gage readings, site then in use; minimum discharge, 2.6 ft³/s, Sept. 16, 1988, no corresponding gage height. Minimum gage height 1.30 ft., Aug. 28, 2012.