USGS Water-Year Summary for Site 01648010

USGS Water-Year Summary 2024

01648010 ROCK CREEK AT JOYCE RD WASHINGTON, DC

LOCATION - Lat 38°57'36.6", long 77°02'31.4" referenced to North American Datum of 1983, Washington, DC, Hydrologic Unit 02070010, on right bank at downstream side of bridge on Joyce Road in Rock Creek Park in Washington, DC, and 6.4 miles upstream from mouth.

DRAINAGE AREA - 63.7 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD - April 2007 to September 2012 (gage heights and discharge measurements only). October 2012 to current year.

GAGE - Water stage recorder and crest-stage gage. Datum of gage is 136.78 ft above North American Vertical Datum of 1988.

REMARKS -

Water Year 2022-2024: Records fair, except those for estimated discharges, which are poor.

Water Year 2021: Records good, except those for estimated discharges, which are poor.

Water Year 2020: Records good, except those above 2,000 ft³/s, which are poor.

Water Years 2017-2019: Records good, except those above 2,000 ft³/s, and those for estimated discharges, which are poor.

Water Year 2016: Records good, except those above 2,000 ft³/s, and those for estimated daily discharges, which are poor.

Water Years 2014-2015: Records good, except those for estimated daily discharges, which are poor.

Water Year 2013 and prior years’ accuracy statements can be found in Annual Water Data Reports.

Flow affected by two upstream reservoirs which control flow from about 25 mi², Needwood Lake on Rock Creek since Sept. 1966 and Bernard Frank Lake on North Branch Rock Creek since February 1968. U.S. Geological Survey water-data telemeter at station.

WATER-QUALITY RECORDS

PERIOD OF DAILY RECORD - WATER TEMPERATURE: June 2012 to current year. SPECIFIC CONDUCTANCE: June 2012 to current year. DISSOLVED OXYGEN: June 2012 to current year. pH: June 2012 to current year. TURBIDITY: June 2012 to current year. CDOM: December 2015 to current year. NITRATE: November 2015 to 03/14/2019.

COOPERATION - Funding for water-quality data collection is provided by the Montgomery County Department of Environmental Protection and the U.S. Geological Survey.

INSTRUMENTATION - Water-quality monitor: 06/2012 to 10/01/2014: YSI 6920V2; 10/01/2014 to 10/01/2021: YSI EXO2; 10/01/2021 to present: YSI EXO3

REMARKS -

Turbidity values greater than 1,000 formazin nepthelometric units (FNU) exceed the instrument calibration range. Values above 1,000 FNU are included in the record but are presumed to have lower precision.

The accuracy limit of the turbidity sensor in low turbidity water is +/- 0.3.

October 1, 2024: Values are censored and qualified as less than (<) 0.3 FNU if they are recorded below 0.3 FNU.

EXTREMES FOR PERIOD OF DAILY RECORD -

SPECIFIC CONDUCTANCE (downstream location): Maximum, 6334 microsiemens per centimeter, February 13, 2025; minimum, 39 microsiemens per centimeter, December 23, 2022.

WATER TEMPERATURE (downstream location): Maximum, 29.27°C on July 10, 2024; minimum, -0.2 °C on many days.

pH(downstream location): Maximum, 8.8 standard units, March 18, 2023; minimum, 6.3 standard units, September 01, 2021.

TURBIDITY (downstream location): Maximum, 794 formazin nephelometric units (FNU), September 01, 2021; minimum, 0.0 formazin nephelometric units (FNU), on July 28, 2023.

DISSOLVED OXYGEN (downstream location): Maximum, 16.14 milligrams per liter, March 4, 2025; minimum, 4.36 milligrams per liter, August 10, 2022.

SPECIFIC CONDUCTANCE (upstream location, discontinued): Maximum, 11700 microsiemens per centimeter, February 2, 2021; minimum, 10 microsiemens per centimeter, October 30, 2012.

WATER TEMPERATURE(upstream location, discontinued): Maximum, 29.6°C, on many days, first occurrence on July 21, 2019; minimum, -0.1°C, on many days, first occurrence on December 28, 2017.

pH(upstream location, discontinued): Maximum, 11.8 standard units, December 13, 2013; minimum, 5.7 standard units, June 27, 2015.

TURBIDITY(upstream location, discontinued): Maximum, 1,500 formazin nephelometric units (FNU), April 20, 2015; minimum, 0.0 formazin nephelometric units (FNU), on several days.

DISSOLVED OXYGEN(upstream location, discontinued): Maximum, 16.2 milligrams per liter, March 27, 2014; minimum, 3.19 milligrams per liter, July 18, 2017.

NITRATE(discontinued): Maximum 1.94 milligrams per liter, on many days, first occurrence on February 07, 2019; minimum 0.15 milligrams per liter, on many days, first occurrence on November 06, 2018.

MEAN VELOCITY FROM 1500kHz ACOUSTIC UNIT: Maximum, 5.58 feet per second, May 3, 2016; minimum, -0.04 feet per second, on September 6&9, 2015.

MEAN VELOCITY FROM 3000kHz ACOUSTIC UNIT: Maximum, 4.63 feet per second, May 3, 2016; minimum,-0.15 feet per second, on January 4, 2016.

	Available Parameters
	00010 Temperature, water(Max.,Min.,Mean) [Discontinued]
	00010 Temperature, water(Max.,Mean,Min.)
	00060 Discharge(Mean)
	00095 Specific cond at 25C(Max.,Min.,Mean) [Discontinued]
	00095 Specific cond at 25C(Max.,Mean,Min.)
	00300 Dissolved oxygen(Max.,Min.,Mean) [Discontinued]
	00300 Dissolved oxygen(Max.,Mean,Min.)
	00400 pH(Max.,Min.,Med.) [Discontinued]
	00400 pH(Min.,Max.,Med.)
	63680 Turbidity, Form Neph(Min.,Max.,Mean) [Discontinued]
	63680 Turbidity, Form Neph(Max.,Mean,Min.)
	72254 Sensor velocity(Max.,Min.,Mean) [Discontinued]
	72254 Sensor velocity(Max.,Min.,Mean) [Discontinued]
	99133 NO3+NO2,water,insitu(Max.,Min.,Mean) [Discontinued]