USGS Water-Year Summary 2022
06800500 Elkhorn River at Waterloo, Nebr.
LOCATION - Lat 41°17'36", long 96°17'02" referenced to North American Datum of 1983, in SE 1/4 SW 1/4 sec.03, T.15 N., R.10 E., Douglas County, NE, Hydrologic Unit 10220003, on right bank downstream of Nebraska Highway 64 bridge at north edge of Waterloo, 3.5 mi downstream from Rawhide Creek, and at mile 13.8.
DRAINAGE AREA - 6,900 mi² of which 1,030 mi² probably is noncontributing.
REVISIONS HISTORY - WSP 1390: 1914 (M), 1915, 1936, 1943(M). WDR NE-94-1: Drainage area.
SURFACE-WATER RECORDS
PERIOD OF RECORD - April 1899 to November 1903, May 1911 to September 1915, August 1928 to current year. Published as "at Arlington" 1899-1903, July 1913 to September 1915. Monthly discharge only for some periods, published in WSP 1310.
GAGE - Water-stage recorder with satellite telemetry. Datum of gage is 1,105.19 ft above North American Vertical Datum of 1988. Prior to September 12, 2016, datum of gage was 1,104.73 ft above National Geodetic Vertical Datum of 1929. See WSP 1918 for history of changes prior to Oct. 1, 1960. Oct. 1, 1960 to July 27, 1978, at datum 2.00 ft higher (1,106.73 ft NGVD29). July 28, 1978 to Nov. 17, 1993, at site 800 ft downstream at present datum.
EXTREMES OUTSIDE PERIOD OF RECORD - Stage and discharge of the flood of June 12, 1944, are the greatest known since at least 1880.
EXTREMES FOR PERIOD OF RECORD - Maximum peak flow, 117,000 ft³/s, March 15, 2019, gage height, 24.23 ft. Peak gage height, 24.68 ft, March 16, 2019, backwater from ice.
WATER-QUALITY RECORDS
PERIOD OF RECORD - Water years 1948-49, 1960, 1967-95, 2003 to current year.
PERIOD OF DAILY RECORD -
WATER TEMPERATURE: October to September 2003, June 2007 to present (seasonal records only).
SPECIFIC CONDUCTANCE: Limited daily records of poor quality during water years 1967 to 1970; March to September 2003, June 2007 to present (seasonal records only).
TURBIDITY: March 2008 to present (seasonal records only).
DISSOLVED OXYGEN: March 2008 to present (seasonal records only).
Nitrate: March 2016 to present (seasonal records only).
INSTRUMENTATION - Seasonal deployment of a continuous water-quality monitor.
Measured parameters include water temperature, specific conductance, dissolved oxygen, turbidity, and nitrate. Turbidity measurements conform to ISO 7027 standards. Dissolved oxygen measurements were collected using a luminescent sensor. Nitrate measurements were collected using a Hach Nitratax sensor with 2 mm wavelength sensing. YSI Exo instrumentation used beginning 2016 and moving forward.
EXTREMES FOR PERIOD OF RECORD -
Extremes computed from periods of approved record since 2002, and may have been exceeded during non-measured periods.
WATER TEMPERATURE: Maximum, 38.3 °C, July 14, 2002; minimum, 0.0 °C, various days during winter periods.
SPECIFIC CONDUCTANCE: Maximum, 796 uS/cm, June 25, 2003 and July 13, 2014; minimum, 105 uS/cm, Aug 16, 2002.
DISSOLVED OXYGEN: Maximum, 22.6 mg/L, September 25, 2012; minimum, 1.2 mg/L, June 4, 2014.
TURBIDITY: Maximum, 3,700 FNU, May 31, 2018 ; minimum, 4.0 FNU, October 8, 2012.
NITRATE: Maximum, 9.7 mg/L N, June 28, 2021; minimum, <0.5 mg/L N on numerous dates