LOCATION.--Lat 42°29'44", long 92°20'03" referenced to North American Datum of 1927, in SE 1/4 NW 1/4 NW 1/4 sec.25, T.89 N., R.13 W., Black Hawk County, IA, Hydrologic Unit 07080205, on left bank near end of East 7th Street, 0.3 mi upstream from bridge on 11th Street in Waterloo, 1.1 mi downstream from Black Hawk Creek, and 162.3 mi upstream from mouth. (map)

DRAINAGE AREA.--5,146 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD.--Discharge records from October 1940 to current year. Prior to April 1941, monthly mean discharge for some periods published in WSP 1308.

REVISED RECORDS.--WSP 1438: Drainage area. WSP 1558: 1950.

GAGE.--Water-stage recorder. Datum of gage is 824.14 ft above National Geodetic Vertical Datum of 1929.

REMARKS.--Minor diurnal fluctuations during periods of low flow due to operations of power plant located 30.3 mi upstream.

Advanced Hydrologic Prediction Service

City of Waterloo

National Streamflow Information Program