LOCATION.--Lat 42°09'25", long 95°48'35" referenced to North American Datum of 1927, in NW 1/4 SE 1/4 SE 1/4 sec.23, T.85 N., R.43 W., Monona County, IA, Hydrologic Unit 10230005, on right bank on downstream side of bridge on State Highway 175, 1.1 mi southwest of intersection of State Highways 175 and 141 in Mapleton, 1.0 mi downstream from Simmons Creek, 2.1 mi upstream from McCleery Creek, and 16.0 mi upstream from mouth. (map)

DRAINAGE AREA.--669 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD.--Discharge records from October 1941 to current year.

REVISED RECORDS.--WSP 1310: 1942 (M), 1946 (M), 1948 (M). WSP 1440: Drainage area.

GAGE.--Water-stage recorder. Datum of gage is 1,080.86 ft above National Geodetic Vertical Datum of 1929. Prior to August 20, 1952, non-recording gage at same site at datum 5.0 ft higher, with supplementary water-stage recorder in operation above 9.5 ft from June 8, 1949, to August 19, 1952; August 20, 1952, to June 20, 1954, water-stage recorder at same site at datum 5.0 ft higher; June 21,1954, to September 6, 1955, non-recording gage at site 1.4 mi upstream at datum 9.05 ft higher; September 7, 1955, to September 20, 1956, non-recording gage, and September 21, 1956, to May 16, 2000, water-stage recorder, both at same site at datum 5.0 ft higher.

WATER-QUALITY RECORDS

PERIOD OF DAILY RECORD.--
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