LOCATION.-- Lat 41°44'20", long 87°53'47" (NAD of 1983), in SE1/4NE1/4 sec.31, T.38 N., R.12 E., Cook County, Hydrologic Unit 07120004, on left bank at upstream side of bridge on German Church Road, 1.1 mi northwest of Willow Springs, and at mile 2.2.

DRAINAGE AREA.-- 16.5 mi².

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: July 1951 to current year.

STAGE: Water years 1994 to current year.

SURFACE-WATER QUALITY

MISCELLANEOUS: Water year 2000; contaminants in streambed sediments, water year 2000.

BIOLOGICAL

ALGAE: Water year 2000.

BENTHIC MACROINVERTEBRATES: Water year 2000.

FISH: Water year 2001.

HABITAT: Water year 2000-01.

REVISED RECORDS.-- WDR IL-75-1: Drainage area.

GAGE.-- Water-stage recorder, phone telemeter, and crest-stage gage. Datum of gage is 606.36 ft above NGVD of 1929 (606.08 ft NAVD 1988). Prior to June 17, 1963, water-stage recorder at same site at datum 3.73 ft higher. However, datum incorrectly published as 609.64 ft above NGVD of 1929 from 1951 to 1963. June 17, 1963, to June 26, 1964, nonrecording gage at site 0.5 mi upstream at datum 4.82 ft higher.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 2,680 ft³/s, Sept. 14, 1961, gage height, 13.71 ft, present datum; minimum daily, 0.1 ft³/s, Dec. 9, 1957.

REMARKS FOR CURRENT YEAR.--Fish community samples were collected as part of the National Water-Quality Assessment program (NAWQA) in the upper Illinois River Basin. Taxonomy is based on Robins and others (1991), except where modified for the family Moronidae (Johnson, 1984) and the order Cyprinidontiformes (Parenti, 1981). Collections were made with a single pass of the entire reach with a barge or a backpack electroshocker with supplementary seine hauls and kicks. Fishes were identified by C. A. Taylor, Illinois Natural History Survey, Champaign. Reach A begins 36 feet upstream of German Church Road and continues upstream for 591 feet.