USGS Water-Year Summary 2019
16210500 Kaukonahua Stream at Waialua, Oahu, HI
LOCATION - Lat 21°33'55.1", long 158°07'13.3" referenced to North American Datum of 1983, Honolulu County, HI, Hydrologic Unit 20060000, 0.01 miles upstream from Farrington Highway (State HWY 930), 0.4 miles east of Waialua High School, and 1.3 miles southwest of Weed Circle.
DRAINAGE AREA - 39.26 mi². from automated delineation using 10-meter National Elevation Dataset digital elevation model data dated September 2006 and Watershed Boundary Dataset dated May 2008, using UTM Zone 4 projection, NAD 83 horizontal datum.
- WDR HI-10-1: Drainage Area.
PERIOD OF RECORD - Annual maximum, water years 1963, 1968 - 2011. September 2012 to current year.
GAGE - Water-stage recorder. Elevation of gage is 15 feet above mean sea level (from topographic map). Water years 1963, 1968-2011, crest-stage gage at same site and datum.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 15,600 ft³/s, April 15, 1963, gage height, 26.40 feet (datum in use at the time of measurement); maximum gage height, 29.11 feet, Dec. 11, 2008, (backwater, tidal effect); minimum daily discharge, 0.32 ft³/s (estimated), June 9, 2015.
PERIOD OF RECORD - Miscellaneous water quality measurements 1970 and 2000. Suspended sediment discharge and concentrations: September 2012 to current year. Turbidity: September 2014 to current year.
PERIOD OF DAILY RECORD - SUSPENDED-SEDIMENT DISCHARGE: September 2012 to current year.
TURBIDITY, water, unfiltered, monochrome near infa-red LED light, 780-900 nm, detection angle 90 +/- 2.5 degrees: September 2014 to current year.
INSTRUMENTATION - Automatic pumping sediment sampler September 2012 to current year. Turbidity sensor September 2014 to current year.
EXTREMES FOR PERIOD OF RECORD - SUSPENDED-SEDIMENT CONCENTRATION: Maximum daily mean 1,760 mg/L (estimated), November 23, 2015; minimum, 4 mg/L on many days.
SUSPENDED-SEDIMENT DISCHARGE: Maximum daily, 7,330 (estimated) tons, November 23, 2015; minimum, 0 tons on many days.
TURBIDITY, water, unfiltered, monochrome near infa-red LED light, 780-900 nm, detection angle 90 +/- 2.5 degrees: Maximum recorded, 6,600 formazin nephelometric units (FNU), April 29, 2019, but may have been higher during periods of missing record; minimum, 0.0 FNU on many days.