LOCATION.--Lat 41°53'58", long 92°28'27"
  referenced to North American Datum of 1927, in SE 1/4 SE 1/4 NE 1/4
  sec.21, T.82 N., R.14 W., Tama County, IA, Hydrologic Unit 07080208,
  on right bank 5 ft upstream from bridge on P Avenue, 0.5 mi northeast
  of Haven, and 3.0 mi upstream from mouth. (map)
  DRAINAGE AREA.--56.1 mi2.
  SURFACE-WATER RECORDS
  PERIOD OF RECORD.--Discharge records from October 1949 to current
  year.
  REVISED RECORDS.--WSP 1708: 1950-55, 1956 (M), 1957, 1958 (M),
  1959.
  GAGE.--Water-stage recorder. Datum of gage is 788.69 ft above
  National Geodetic Vertical Datum of 1929. Prior to October 1, 1971,
  at datum 10.00 ft higher.