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USGS 01646500 POTOMAC RIVER NEAR WASH, DC LITTLE FALLS PUMP STA

PROVISIONAL DATA SUBJECT TO REVISION

Click to hidestation-specific text
Click for larger image LOCATION.--Lat 38°56'59.2", long 77°07'39.5", Montgomery County, MD, Hydrologic Unit 02070008, on left bank just upstream from Little Falls Dam, 1 mi upstream from District of Columbia boundary line, 1.2 mi upstream from Chain Bridge, 1.8 mi east of Langley, Fairfax County, and at mile 117.4.
DRAINAGE AREA.--11,560 mi2.
REVISIONS HISTORY.--
  • WSP 726: Drainage area.
  • WDR MD-DE-75-1: 1973-74(M).
  • https://waterdata.usgs.gov/nwis/dv/?site_no=01646500: 2018.
  • https://waterdata.usgs.gov/nwis/uv/?site_no=01646500: 2021.
  • Discharge for Measurement 385 made on 06/25/2021 was revised on 09/22/2021 due to an error in computation.
PERIOD OF RECORD.--March 1930 to current year.
GAGE.--Water-stage recorder, crest-stage gage, and concrete control. Datum of gage is 37.20 ft above North American Vertical Datum of 1988. Prior to Jun 7, 1930, nonrecording gage, and June 7, 1930 to Jan. 22, 1965, water-stage recorder at site 1 mi upstream on right bank at same gage datum.
REMARKS.--Diversions since June 1959. U.S. Geological Survey satellite data-collection platform at station.
EXTREMES OUTSIDE PERIOD OF RECORD.--Flood of June 2, 1889, was of approximately the same magnitude as that of March 19, 1936.
COOPERATION.--Funding for the operation of this station is provided by the U.S. Geological Survey. Access to gage site provided by the Baltimore District, U.S. Army Corps of Engineers.
Boating safety tips
This station managed by the MD-DE-DC Water Science Center Baltimore office.

Available Parameters Available Period
  
2019-07-24  2026-10-14
2007-10-01  2019-10-01
2007-10-01  2019-10-01
2007-10-01  2019-10-01
2013-11-23  2019-05-27
1972-06-09  2026-10-14
2007-10-01  2026-10-14
2019-07-24  2026-10-14
2007-10-01  2019-10-01
2013-11-23  2019-05-27
2019-07-24  2026-10-14
2013-11-23  2019-05-27
2019-07-24  2026-10-14
2013-11-23  2019-05-27
2007-10-01  2026-10-14
2019-07-24  2026-10-14
2013-11-23  2019-05-27
2019-07-24  2026-10-14
2011-12-03  2019-06-11







 (7)
 

  -- or --

 


 

Summary of all available data for this site
Instantaneous-data availability statement

Temperature, water, degrees Celsius, 1.0 ft from riverbed (bottom), [Discontinued]
 
-- Data temporarily unavailable for the time period specified --

Temperature, water, degrees Celsius, 4.1 ft from riverbed (middle), [Discontinued]
 
-- Data temporarily unavailable for the time period specified --

Temperature, water, degrees Celsius, 7.1 ft from riverbed (top), [Discontinued]
 
-- Data temporarily unavailable for the time period specified --

Most recent instantaneous value: 18.5 10-14-2026   09:50 EDT
Graph of  Temperature, water, degrees Celsius

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Temperature, water, degrees Celsius, From multiparameter sonde, [Discontinued]
 
-- Data temporarily unavailable for the time period specified --

Most recent instantaneous value: 24100 10-14-2026   09:50 EDT
Graph of  Discharge, cubic feet per second

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Daily discharge, cubic feet per second -- statistics for Oct 14 based on 96 water years of record more
Min
(1931)
25th
percen-
tile
Median 75th
percen-
tile
Mean Most Recent
Instantaneous
Value Oct 14
Max
(1980)
538 1480 2510 4130 4780 24100 51400

Most recent instantaneous value: 5.24 10-14-2026   09:50 EDT
Graph of  Gage height, feet

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Specific conductance, water, unfiltered, microsiemens per centimeter at 25 degrees Celsius, 7.1 ft from riverbed (top), [Discontinued]
 
-- Data temporarily unavailable for the time period specified --

Most recent instantaneous value: 335 10-14-2026   09:50 EDT
Graph of  Specific conductance, water, unfiltered, microsiemens per centimeter at 25 degrees Celsius

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Specific conductance, water, unfiltered, microsiemens per centimeter at 25 degrees Celsius, From multiparameter sonde, [Discontinued]
 
-- Data temporarily unavailable for the time period specified --

Most recent instantaneous value: 9.6 10-14-2026   09:50 EDT
Graph of  Dissolved oxygen, water, unfiltered, milligrams per liter

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Dissolved oxygen, water, unfiltered, milligrams per liter, From multiparameter sonde, [Discontinued]
 
-- Data temporarily unavailable for the time period specified --

Most recent instantaneous value: 8.0 10-14-2026   09:50 EDT
Graph of  pH, water, unfiltered, field, standard units

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pH, water, unfiltered, field, standard units, From multiparameter sonde, [Discontinued]
 
-- Data temporarily unavailable for the time period specified --

Most recent instantaneous value: 42.28 10-14-2026   09:50 EDT
Graph of  Stream water level elevation above NAVD 1988, in feet

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Most recent instantaneous value: 61.4 10-14-2026   09:50 EDT
Graph of  Turbidity, water, unfiltered, monochrome near infra-red LED light, 780-900 nm, detection angle 90 +-2.5 degrees, formazin nephelometric units (FNU), [(2)]

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Turbidity, water, unfiltered, monochrome near infra-red LED light, 780-900 nm, detection angle 90 +-2.5 degrees, formazin nephelometric units (FNU), From multiparameter sonde, [Discontinued]
 
-- Data temporarily unavailable for the time period specified --

Most recent instantaneous value: 1.05 10-14-2026   10:30 EDT
Graph of  Nitrate plus nitrite, water, in situ, milligrams per liter as nitrogen

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Nitrate plus nitrite, water, in situ, milligrams per liter as nitrogen, SUNA, [Discontinued]
 
-- Data temporarily unavailable for the time period specified --