LOCATION.-- Lat 41°47'51", long 89°58'21" (NAD of 1983), in NE1/4NW1/4 sec.19, T.21 N., R.5 E., Whiteside County, Hydrologic Unit 07090005, on right bank at upstream side of bridge on Prairie Center Road 8 mi southwest of Morrison, 0.2 mi upstream from French Creek, 7.5 mi downstream from Little Rock Creek, and at mile 15.2.

DRAINAGE AREA.-- 164 mi².

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: March 1940 to September 1942, October 1977 to September 1986. Published as "near Morrison" 1942-58.

PARTIAL RECORD: Annual maximum, water years 1959-71 and 1987 to 2000 (discontinued).

REVISED RECORDS.-- WSP 1308: 1940(M). WDR IL-78-1: Drainage area.

GAGE.-- Crest-stage gage. Datum of gage is 606.91 ft. above NGVD of 1929 (levels by Illinois Department of Transportation) (606.79 ft NAVD 1988). October 1942 to September 1958, water-stage recorder at site near Morrison about 3 mi upstream at datum 13.50 ft higher. Oct. 1, 1977, to Mar. 11, 1981, water-stage recorder at site 85 ft upstream at same datum. Mar. 12 to Nov. 3, 1981, nonrecording gage at site 100 ft downstream at same datum.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 5,770 ft³/s, Jan. 6, 1946, gage height, 16.04 ft, site and datum then in use; minimum, 1.0 ft³/s, Dec. 4, 1940, result of regulation.

EXTREMES OUTSIDE PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Flood of June 5, 2002 reached a stage of 17.84 ft, discharge 5,230 ft³/s. Flood of 1937 reached a stage of 17.7 ft, from floodmark, discharge not determined for site near Morrison and datum then in use.