LOCATION.--Lat 41°57'52", long 95°59'30" referenced to North American Datum of 1927, in NW 1/4 NW 1/4 NE 1/4 sec.32, T.83 N., R.44 W., Monona County, IA, Hydrologic Unit 10230004, on left bank on upstream side of bridge on County Highway E54, 1.0 mi west of gaging station Little Sioux River near Turin (station 06607500), 4.0 mi southwest of Turin, and 12.5 mi upstream from mouth. (map)

DRAINAGE AREA.--900 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD.--Discharge records from May 1942 to current year. Records for May 1942 to January 1958 are not equivalent owing to diversion from Little Sioux River through equalizer ditch 1.5 mi upstream. Records prior to 1950 are not equivalent owing to diversion to Little Sioux River through diversion ditch 10.2 mi upstream.

REVISED RECORDS.--WSP 1440: Drainage area. WSP 1560: Drainage area. WDR IA-95-1: Period of record.

GAGE.--Water-stage recorder. Datum of gage is 1,015.00 ft above National Geodetic Vertical Datum of 1929 (U.S. Army Corps of Engineers benchmark). May 7, 1942, to October 13, 1953, non-recording gage, and October 14, 1953, to September 30, 1975, water-stage recorder, both at same site at datum 5.00 ft higher.

REMARKS.--Monona-Harrison Ditch is a dug channel and is a continuation of West Fork Ditch, paralleling the Little Sioux River, and discharging into the Missouri River 1.5 mi upstream from the mouth of the Little Sioux River.

WATER-QUALITY RECORDS

PERIOD OF DAILY RECORD.--
SUSPENDED-SEDIMENT DISCHARGE: April 1939 to September 1951, September 1957 to January 1958, October to December 1959, March to November 1960, March to November 1961, March to November 1962, March to November 1963, March to December 1964, April 1965 to December 1968, March to June 1969, records provided by U.S. Army Corps of Engineers.

U.S. Army Corps of Engineers - Omaha District