Click
to
hide
Water-Year
Summary
instructions
and
information
- Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
- For water years 2014 onward, choose a water year and parameter and an on-demand Water-Year Summary report will be generated.
- For water years 2006 through 2013, choose a water year and an Annual Water Data Report will be provided.
- For water years 2005 and earlier, Annual Water Data Reports may be available in digital format.
- Not all sites have reports available for every water year.
USGS Water-Year Summary 2024
01645704 DIFFICULT RUN ABOVE FOX LAKE NEAR FAIRFAX, VA
LOCATION - Lat 38°53'04.5", long 77°19'57.8" referenced to North American Datum of 1927, Fairfax County, VA, Hydrologic Unit 02070008, on right bank 0.8 mi downstream from State Highway 665, 0.5 mi upstream from Fox Lake, and 3.0 mi northwest of Fairfax.
DRAINAGE AREA - 5.49 mi².
REVISIONS HISTORY - WDR VA-2012: 2008-11.
SURFACE-WATER RECORDS
PERIOD OF RECORD - September 2007 to current year.
GAGE - Water-stage recorder. Datum of gage is 288.23 feet NAVD of 1988.
WATER-QUALITY RECORDS
PERIOD OF RECORD - October 2007 to current year.
PERIOD OF DAILY RECORD -
DISSOLVED OXYGEN: May 2009 to current year.
pH: October 2007 to current year.
SPECIFIC CONDUCTANCE: October 2007 to current year.
TURBIDITY: October 2007 to current year.
WATER TEMPERATURE: October 2007 to current year.
DISSOLVED OXYGEN: May 2009 to current year.
pH: October 2007 to current year.
SPECIFIC CONDUCTANCE: October 2007 to current year.
TURBIDITY: October 2007 to current year.
WATER TEMPERATURE: October 2007 to current year.
INSTRUMENTATION - Water-quality monitor. Electronic data logger with 15-minute recording interval.
EXTREMES FOR PERIOD OF DAILY RECORD -
DISSOLVED OXYGEN: Maximum: 14.7 mg/L, on several days, but may have been higher during periods of missing record; minimum: 3.5 mg/L on July 6, 2012, but may have been lower during periods of missing record.
pH: Maximum: 7.8 standard units, Feb. 26, 27, 2008, but may have been higher during periods of missing record; minimum: 5.9 standard units, Sept. 2, 2013, but may have been lower during periods of missing record.
SPECIFIC CONDUCTANCE: Maximum: 8,620 microsiemens/cm, Jan. 19, 2011, but may have been higher during periods of missing record; minimum: 42 microsiemens/cm, Sept. 6, 2008, but may have been lower during periods of missing record.
TURBIDITY: Maximum: 1,340 FNU, Aug. 16, 2016, but may have been higher during periods of missing record; minimum: 0.0 FNU on many days.
WATER TEMPERATURE: Maximum: 28.0°C, July 25, 2010 and July 25, 2011, but may have been higher during periods of missing record; minimum: -0.7°C, Mar. 4, 2014, but may have been lower during periods of missing record.
DISSOLVED OXYGEN: Maximum: 14.7 mg/L, on several days, but may have been higher during periods of missing record; minimum: 3.5 mg/L on July 6, 2012, but may have been lower during periods of missing record.
pH: Maximum: 7.8 standard units, Feb. 26, 27, 2008, but may have been higher during periods of missing record; minimum: 5.9 standard units, Sept. 2, 2013, but may have been lower during periods of missing record.
SPECIFIC CONDUCTANCE: Maximum: 8,620 microsiemens/cm, Jan. 19, 2011, but may have been higher during periods of missing record; minimum: 42 microsiemens/cm, Sept. 6, 2008, but may have been lower during periods of missing record.
TURBIDITY: Maximum: 1,340 FNU, Aug. 16, 2016, but may have been higher during periods of missing record; minimum: 0.0 FNU on many days.
WATER TEMPERATURE: Maximum: 28.0°C, July 25, 2010 and July 25, 2011, but may have been higher during periods of missing record; minimum: -0.7°C, Mar. 4, 2014, but may have been lower during periods of missing record.
