LOCATION.--Lat 40°40'55", long 95°50'48" referenced to North American Datum of 1927, in NE 1/4 NW 1/4 NE 1/4 sec.9, T.8 N., R.14 E., Otoe County, NE, Hydrologic Unit 10240001, on right bank 0.7 mi upstream from bridge on State Highway 2 in Nebraska City, and 562.6 mi upstream from mouth. Sediment samples collected by boat in vicinity of gage. (map)

DRAINAGE AREA.--410,000 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD.--Discharge records from August 1929 to current year. Stage-only records collected in this vicinity from August 1878 to December 1899 in reports of Missouri River Commission.

REVISED RECORDS.--WSP 761: Drainage area.

GAGE.--Water-stage recorder. Datum of gage is 905.61 ft above North American Vertical Datum 0f 1988. Prior to August 1, 2016, datum of gage was 905.36 ft above National Geodetic Vertical Datum of 1929, supplementary adjustment of 1954. August 1, 1878, to October 30, 1888, non-recording gage at site 1.2 mi downstream at datum 493.22 ft lower (St. Louis directrix); October 31, 1888, to December 31, 1899, non-recording gage at site 0.7 mi downstream at datum 493.22 ft lower (St. Louis directrix); August 12, 1929, to October 21, 1931, non-recording gage, and October 22, 1931, to March 31, 1963, water-stage recorder, both at site 0.7 mi downstream at datum 1.42 ft lower.

REMARKS.--Flow regulated by upstream main-stem reservoirs. Fort Randall Dam was completed in July 1952, with storage beginning in December 1952. Gavins Point Dam was completed in July 1955, with storage beginning in December 1955.

WATER-QUALITY RECORDS

PERIOD OF RECORD.--Water years 1951 to current year.

PERIOD OF DAILY RECORD.--
SPECIFIC CONDUCTANCE: Daily instantaneous values collected in conjunction with suspended-sediment samples, January 1951 to December 1977, October 1991 to September 2010, records fragmentary for some periods. Beginning October 2010, daily instantaneous values published in combined water-quality table. Daily mean, March 2006 to November 2007.
WATER TEMPERATURE: Daily instantaneous values collected in conjunction with suspended-sediment samples, May 1951 to December 1977, October 1991 to September 2010, records fragmentary for some periods. Beginning October 2010, daily instantaneous values published in combined water-quality table. Daily mean, March 2006 to November 2007, September 2012.
DISSOLVED OXYGEN: March 2006 to November 2007.
pH: March 2006 to October 2007.
TURBIDITY: March 2006 to November 2007.
SUSPENDED-SEDIMENT CONCENTRATION AND DISCHARGE: August 1957 to December 1959, March to November 1960, March to November 1961, March to November 1962, March to November 1963, March to November 1964, April to December 1965, March 1966 to December 1967, March to December 1968, March 1969 to September 1971, October 1971 to September 1976, October 1991 to current year. Prior to October 1971, suspended-sediment discharge records only, provided by the U.S. Army Corps of Engineers.

Advanced Hydrologic Prediction Service

U.S. Army Corps of Engineers - Omaha District

National Streamflow Information Program