USGS Water-Year Summary 2024
16213000 Waikele Stream at Waipahu, Oahu, HI
LOCATION - Lat 21°23'00.5", long 158°00'39.3" referenced to North American Datum of 1983, Honolulu County, HI, Hydrologic Unit 20060000, on left bank 300 ft upstream from bridge on Highway 90, and 0.3 mi southwest of former sugar refinery at Waipahu.
DRAINAGE AREA - 45.14 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.
REVISIONS HISTORY - WSP 1639: 1955(M). WSP 1937: Drainage Area. WSP 2137: 1965. WDR HI-06-01, 2000-2005 (P).WDR HI-10-1: Drainage Area.
SURFACE-WATER RECORDS
PERIOD OF RECORD - June to October 1951, December 1951 to October 1959, July 1960 to current year.
GAGE - Water-stage recorder and concrete control. Datum of gage is 1.37 ft above mean sea level (by stadia survey). Prior to July 1, 1960, at site 300 ft downstream at datum 1.30 ft higher.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 22,600 ft³/s, December 11, 2008, gage height, 18.85 feet, from rating curve extended above 730 ft³/s on basis of slope-area measurement of peak flow; no flow for part of February 25, 1978.
WATER-QUALITY RECORDS
PERIOD OF RECORD - Specific conductance and water temperature 1973-1981, 1999-2001; Suspended sediment concentrations and discharge 1972-1993, 2008-2010, October 2017 to September 2021; Miscellaneous water quality measurements 1967 to current year; Turbidity October 2017 to September 2021.
PERIOD OF DAILY RECORD - Specific conductance and water temperature 1973-1981, 1999-2001; Suspended sediment concentrations and discharge 1972-1993, 2008-2010, October 2017 to September 2021; Turbidity October 2017 to September 2021.
INSTRUMENTATION - Water-quality monitor 1973 to 1981, 1999-2001. Automatic pumping sediment sampler 1972-1993, 2008-2010, October 2017 to September 2021. Automatic pumping water quality sampler 1999-2001, August 2017 to September 2021. Turbidity sensor October 2017 to September 2021.
EXTREMES FOR PERIOD OF RECORD - SUSPENDED-SEDIMENT CONCENTRATION: maximum daily mean, 6,620 mg/L, December 11, 2008; minimum daily mean, 1 mg/L, March 20-22, 1989. SUSPENDED-SEDIMENT DISCHARGE: maximum daily, 227,000 tons, December 11, 2008; minimum daily, 0.01 tons, August 29-30, 1992. Turbidity: Maximum 5,830 FNU March 9, 2021; minimum 0 FNU on many days.