LOCATION.--Lat 42°38'54", long 92°27'54" referenced to North American Datum of 1927, in NW 1/4 NW 1/4 SE 1/4 sec.35, T.91 N., R.14 W., Bremer County, IA, Hydrologic Unit 07080201, on left bank 300 ft downstream from bridge on County Highway C50 in Janesville, 3.6 mi upstream from West Fork Cedar River, and 182.6 mi upstream from mouth. (map)

DRAINAGE AREA.--1,661 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD.--Discharge records from October 1904 to September 1906, October 1914 to September 1927, October 1932 to September 1942, October 1945 to current year. Prior to May 1946, monthly mean discharge for some periods published in WSP 1308. Prior to October 1906, published as "Red Cedar River at Janesville".

REVISED RECORDS.--WSP 1438: Drainage area. WSP 1558: 1906 (M), 1915-16 (M), 1917, 1918-19 (M), 1920-27, 1933-37 (M), 1940-42 (M). WDR IA-97-1: 1996.

GAGE.--Water-stage recorder. Datum of gage is 868.26 ft above National Geodetic Vertical Datum of 1929. Prior to July 26, 1919, non-recording gage at site 1,000 ft downstream at datum 4.0 ft lower; July 26, 1919, to September 30, 1927, November 14, 1932, to September 30, 1942, and April 26, 1946, to November 10, 1949, non-recording gage at county bridge 300 ft upstream at same datum.

REMARKS.--Minor diurnal fluctuations during periods of low flow due to operations of power plant located 10.0 mi upstream.

WATER-QUALITY RECORDS

PERIOD OF RECORD.--Water years 1988, 2001-2002, 2004, 2011-2012. Period of record includes water-quality data published in USGS annual reports and various project reports.

Advanced Hydrologic Prediction Service

National Streamflow Information Program