LOCATION.--Lat 40°36'06", long 95°38'42" referenced to North American Datum of 1983, in NE 1/4 SW 1/4 SE 1/4 sec.11, T.67 N., R.42 W., Fremont County, IA, Hydrologic Unit 10240004, on left bank on downstream side of bridge on U.S. Highway 275 and State Highway 333 in Hamburg, 4.7 mi downstream from confluence of East Nishnabotna River and West Nishnabotna River, and 11.0 mi upstream from mouth. (map)

DRAINAGE AREA.--2,806 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD.--Discharge records from March 1922 to September 1923, October 1928 to current year. March 1922 to September 1923, monthly mean discharge for some periods published in WSP 1310.

REVISED RECORDS.--WSP 1240: 1923, 1929-37, 1938-40 (M), 1943 (M). WSP 1440: Drainage area. WDR IA-74-1: 1973. WDR-US-2008: Location.

GAGE.--Water-stage recorder. Datum of gage is 894.17 ft above National Geodetic Vertical Datum of 1929. Prior to October 1, 1923, non-recording gage at site 3.5 mi downstream at different datum; October 5, 1928, to September 6, 1929, non-recording gage at site 2.7 mi upstream at datum 0.42 ft higher; September 7, 1929, to June 5, 1947, non-recording gage at site 2.5 mi upstream at same datum; June 6 to July 22, 1947, non-recording gage at site 2.7 mi upstream at different datum; July 23, 1947, to November 16, 1950, non-recording gage, and November 17, 1950, to October 2, 2007, water-stage recorder, both at site 2.5 mi upstream at same datum.

WATER-QUALITY RECORDS

PERIOD OF RECORD.--Water years 1979-1993, 2004 to current year.

PERIOD OF DAILY RECORD.--
SPECIFIC CONDUCTANCE: Daily instantaneous, October 1979 to September 1981.
WATER TEMPERATURE: Daily instantaneous, October 1979 to September 1981.
SUSPENDED-SEDIMENT DISCHARGE: April 1939 to September 1951, records provided by U.S. Army Corps of Engineers.

Advanced Hydrologic Prediction Service

U.S. Army Corps of Engineers - Omaha District

National Streamflow Information Program