LOCATION.--Lat 41°39'24", long 91°32'27" referenced to North American Datum of 1927, in NE 1/4 NE 1/4 NE 1/4 sec.16, T.79 N., R.6 W., Johnson County, IA, Hydrologic Unit 07080209, on right bank 25 ft downstream from the University of Iowa Hydraulics Laboratory in Iowa City, 175 ft downstream from University dam, 0.8 mi upstream from Ralston Creek, 3.6 mi downstream from Clear Creek, and 72.3 mi upstream from mouth. (map)

DRAINAGE AREA.--3,271 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD.--Discharge records from June 1903 to current year. Prior to April 1918, monthly mean discharge for some periods published in WSP 1308.

GAGE.--Water-stage recorder. Datum of gage is 29.00 ft above Iowa City datum and 617.27 ft above National Geodetic Vertical Datum of 1929. June 1, 1903, to July 21, 1906, non-recording gage at site 1,200 ft upstream at datum 13.05 ft higher; November 29, 1907, to October 29, 1913, non-recording gage at site 200 ft upstream at different datum; October 30, 1913, to November 18, 1921, non-recording gage at site 2,600 ft downstream at datum 10.20 ft higher; November 19, 1921, to September 30, 1922, water-stage recorder at same site at datum 1.00 ft higher; October 1, 1930, to September 30, 1934, at same site at Iowa City datum, or 29.00 ft lower; October 1, 1934, to September 30, 1972, at datum 10.00 ft higher.

REMARKS.--Minor fluctuations during periods of low flow due to operations of power plant located 175 ft upstream. Flow regulated by Coralville Lake (station 05453510), 9.1 mi upstream, since September 17, 1958.

WATER-QUALITY RECORDS

PERIOD OF RECORD.--Water years 1906-1907, 1944-2002, 2007-2008, 2012.

PERIOD OF DAILY RECORD.--
SPECIFIC CONDUCTANCE: Daily instantaneous values collected in conjunction with suspended-sediment samples, October 1968 to September 1987, records fragmentary.
WATER TEMPERATURE: Daily instantaneous values collected in conjunction with suspended-sediment records, January 1944 to September 1987, records fragmentary.
SUSPENDED-SEDIMENT CONCENTRATION AND DISCHARGE: October 1943 to September 1987.

Advanced Hydrologic Prediction Service

City of Coralville

City of Iowa City

University of Iowa

Cooperative Water Program