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Important for you to know:

  • New to WDFN: see current water conditions throughout the state using the new State Pages. Filter by continuous data type and age of data, view latest values, and link to graphing options to explore the data further. To learn more, read our announcement on the Water Data for the Nation blog.
Important Legacy real-time page

USGS Parameter Group Data Types Start Date End Date
Biological Water-quality 2014-06-27 2014-06-27
Information Water-quality 2011-07-13 2024-03-07
Inorganics, Major, Metals Water-quality 1945-04-03 2023-11-08
Inorganics, Major, Non-metals Daily Values, Unit Values, Water-quality 1945-04-03 2024-11-21
Inorganics, Minor, Non-metals Water-quality 2014-06-27 2014-06-27
Inorganics, Minor, metals Water-quality 1945-04-03 2019-09-11
Microbiological Water-quality 2013-01-10 2023-11-08
Nutrient Daily Values, Unit Values, Water-quality 1945-04-03 2024-11-21
Organics, other Water-quality 2014-04-07 2014-07-02
Organics, pesticide Water-quality 2014-04-07 2014-07-02
Physical Daily Values, Unit Values, Water-quality 1935-04-01 2024-11-21
Radiochemistry Water-quality 2014-06-27 2014-06-27
Sediment Water-quality 2011-07-13 2023-11-08
Stable Isotopes Water-quality 2011-09-14 2018-09-28
n/a Peak Measurements 1935-09-06 2022-12-23
n/a Site Visits 1935-02-12 2024-10-15
n/a USGS Annual Water Data Reports Site 2006-01-01 2023-01-01
Water Data for the Nation inventory

Monitoring location 01646000 is associated with a Stream in Fairfax County, Virginia. Current conditions of Discharge, Dissolved oxygen, Gage height, and more are available. Water data back to 1935 are available online.

Metadata Element Location Metadata Metadata Code
Agency
U.S. Geological Survey USGS
Site identification number
01646000 n/a
Site name
DIFFICULT RUN NEAR GREAT FALLS, VA n/a
Site type
Stream
ST
DMS latitude 385833 n/a
DMS longitude 0771446 n/a
Decimal latitude 38.97594346 n/a
Decimal longitude -77.24581439 n/a
Latitude-longitude method
Interpolated from MAP. M
Latitude-longitude accuracy
Unknown or unspecified. U
Latitude-longitude datum
North American Datum of 1927 NAD27
Decimal Latitude-longitude datum North American Datum of 1983 NAD83
District
Virginia 51
State
Virginia 51
County
Fairfax County 059
Country US n/a
Land net location description n/a
Name of location map FALLS CHURCH n/a
Scale of location map 24000 n/a
Altitude of Gage/land surface 150.94 feet n/a
Method altitude determined GNSS3 - Level 3 Quality Survey Grade Global Navigation Satellite System Y
Altitude accuracy .13 feet n/a
Altitude datum
North American Vertical Datum of 1988 NAVD88
Subbasin hydrologic unit
Middle Potomac-Catoctin 02070008
Drainage basin
n/a
Topographic setting
n/a
Flags for instruments at site NNNNYNNNNNNNNNNNNNNNNNNNNNNNNN n/a
Date of first construction
n/a
Date site established or inventoried 19901213 n/a
Drainage area
57.8 square miles n/a
Contributing drainage area n/a
Time Zone abbreviation EST n/a
Site honors Daylight Saving Time
Y n/a
Data reliability
n/a
Data-other GW files NNNNNNNN n/a
National aquifer n/a
Local aquifer n/a
Local aquifer type
n/a
Well depth n/a
Hole depth
n/a
Source of depth data n/a
Project number n/a

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US Environmental Protection Agency (EPA)