USGS Water-Year Summary 2024
04137500 AU SABLE RIVER NEAR AU SABLE, MI
LOCATION - Lat 44°26'11", long 83°26'02" referenced to North American Datum of 1927, in NE 1/4 NW 1/4 sec.35, T.24 N., R.8 E., Iosco County, MI, Hydrologic Unit 04070007, at bridge on Rea Road, 5.5 mi northwest of Au Sable, and 10.4 mi upstream from mouth.
DRAINAGE AREA - 1,739 mi².
REVISIONS HISTORY - WDR MI-96-1: Drainage area.
SURFACE-WATER RECORDS
PERIOD OF RECORD - August 1987 to current year. Records for July 1939 to September 1940, published in WSP 874, 894, and 1307, have been found to be unreliable and should not be used.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 583.36 ft above NAVD88, converted on July 9, 2020 from NGVD29.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 5,850 ft³/s, Mar. 28, 1991, gage height, 16.27 ft; minimum discharge, 117 ft³/s, Apr. 12, 2007, discharge less than indicated value, which is a minimum recordable discharge at this site, result of regulation.
WATER-QUALITY RECORDS
PERIOD OF RECORD - Water years 1978-94, 1996 to current year.
PERIOD OF DAILY RECORD - SPECIFIC CONDUCTANCE: April 1978 to September 1981, March 2011 to October 2014.
pH: March 2011 to October 2014.
WATER TEMPERATURE: April 1978 to September 1981, July 1996 to current year.
DISSOLVED OXYGEN: July 1996 to current year.
TURBIDITY: March 2011 to October 2014.
INSTRUMENTATION - Water-quality monitor since July 11, 1996. Automatic (event-driven) pump sampler from Nov. 30, 2010 to Sept. 9, 2013. Data for parameter code 63680 (Turbidity) was collected using a probe with the following specifications: turbidity, water, monochrome near infrared LED light, 780-900 nm, detection angle 90 +/- 2.5 degrees, FNU (Formazin Nephelometric Units).
EXTREMES FOR PERIOD OF DAILY RECORD - SPECIFIC CONDUCTANCE (water years 1978-79, 2011-15): Maximum, 347 microsiemens, Apr. 10, 2014; minimum, 216 microsiemens, May 3, 2014.
pH: Maximum, 8.5 units, on several days in water year 2012; minimum, 7.6 units, Mar. 8, 2014.
WATER TEMPERATURE (water years 1979-80, 1996 to current year): Maximum, 28.0°C, Aug. 8, 1979; minimum, 0.0°C, on many days during winter periods.
DISSOLVED OXYGEN: Maximum, 14.7 mg/L, Mar. 10, 2011; minimum, 5.5 mg/L, July 19, 2002.
TURBIDITY: Maximum, 100 FNU, Nov. 28, 2011; minimum, 0.0 FNU, on many days.
EXTREMES OUTSIDE OF PERIOD OF DAILY RECORD.--Specific conductance of 354 microsiemens was measured Feb. 3, 1988. A pH of 7.4 units was measured Mar. 14, 1979 and Jan. 17, 1984.