LOCATION.--Lat 42°29'09", long 96°24'49"
referenced to North American Datum of 1927, in NW 1/4 SE 1/4 sec.16,
T.29 N., R.9 E., Dakota County, NE, Hydrologic Unit 10230001, on
right bank on upstream side of bridge on U.S. Highway 20 and 77 in
South Sioux City, 1.9 mi downstream from Big Sioux River, and 732.2
mi upstream from mouth. Sediment samples collected by boat in
vicinity of gage. (map)
DRAINAGE AREA.--314,600 mi2.
SURFACE-WATER RECORDS
PERIOD OF RECORD.--Discharge records from October 1897 to current
year. Prior to October 1928 and October 1931 to September 1938,
monthly mean discharge published in WSP 1310. January 1879 to
December 1890, monthly mean discharge published in House Document
238, 73rd Congress, 2nd session, Missouri River. Gage-height records
collected in this vicinity from September 1878 to December 1899
published in reports of the Missouri River Commission, and since July
1889 in reports of the U.S. National Weather Service.
REVISED RECORDS.--WSP 716: 1929-30. WSP 876: Drainage area.
GAGE.--Water-stage recorder. Datum of gage is
1,057.42 ft above North American Vertical Datum of 1988. Prior to
August 1, 2016, datum of gage was 1,056.98 ft above National Geodetic
Vertical Datum of 1929. September 2, 1878, to December 31,
1905, non-recording gage at several sites within 1.7 mi of current
site at various datums; January 1, 1906, to February 14, 1935,
non-recording gage, and February 15, 1935, to September 30, 1969,
water-stage recorder, both at site 227 ft downstream at datum 19.98
ft higher; October 1, 1969, to September 30, 1970, water-stage
recorder at site 227 ft downstream at datum 20.00 ft higher; October
1, 1970, to January 30, 1981, water-stage recorder at site 227 ft
downstream at same datum.
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 1972-2000, 2004 to current year.
Daily sediment loads for October 1954 to September 1971 are in
reports of the U.S. Army Corps of Engineers.
PERIOD OF DAILY RECORD.--
SPECIFIC CONDUCTANCE: Daily instantaneous values collected in
conjunction with suspended-sediment samples, October 1972 to
September 1976, October 1977 to September 1981, October 1991 to
September 2000, October 2003 to September 2010, records fragmentary
for some periods. Beginning October 2010, daily instantaneous values
published in combined water-quality table.
WATER TEMPERATURE: Daily instantaneous values collected in
conjunction with suspended-sediment samples, October 1971 to
September 1976, October 1977 to September 1981, October 1991 to
September 2000, October 2003 to September 2010, records fragmentary
for some periods. Beginning October 2010, daily instantaneous values
published in combined water-quality table. Daily mean, October 2011
to current year.
SUSPENDED-SEDIMENT CONCENTRATION AND DISCHARGE: October 1954 to
December 1959, April to November 1960, March to November 1961, March
to November 1962, March to November 1963, March 1964 to September
1971, October 1971 to September 1976, October 1991 to September 2000,
October 2003 to current year. Prior to October 1971,
suspended-sediment discharge records only, provided by U.S. Army
Corps of Engineers.
National Weather Service River
Forecast
Advanced
Hydrologic Prediction Service
