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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
Information Water-quality 1981-11-17 1987-08-24
Inorganics, Major, Metals Water-quality 1964-05-22 1964-05-22
Inorganics, Major, Non-metals Water-quality 1964-05-22 1964-05-22
Inorganics, Minor, metals Water-quality 1964-05-22 1964-05-22
Nutrient Water-quality 1964-05-22 1964-05-22
Physical Daily Values, Unit Values, Water-quality 1946-06-21 2024-11-15
n/a Peak Measurements 1947-04-16 2023-05-01
n/a Site Visits 1946-06-21 2024-11-15
n/a USGS Annual Water Data Reports Site 2007-01-01 2023-01-01
Water Data for the Nation inventory

Monitoring location 01661500 is associated with a Stream in St. Mary's County, Maryland. Current conditions of Discharge and Gage height are available. Water data back to 1946 are available online.

Metadata Element Location Metadata Metadata Code
Agency
U.S. Geological Survey USGS
Site identification number
01661500 n/a
Site name
ST MARYS RIVER AT GREAT MILLS, MD n/a
Site type
Stream
ST
DMS latitude 381430.3 n/a
DMS longitude 0763013.2 n/a
Decimal latitude 38.24175 n/a
Decimal longitude -76.5036667 n/a
Latitude-longitude method
Interpolated from MAP. M
Latitude-longitude accuracy
Accurate to + or - 1 sec. S
Latitude-longitude datum
North American Datum of 1983 NAD83
Decimal Latitude-longitude datum North American Datum of 1983 NAD83
District
Maryland 24
State
Maryland 24
County
St. Mary's County 037
Country US n/a
Land net location description n/a
Name of location map n/a
Scale of location map n/a
Altitude of Gage/land surface 6.86 feet n/a
Method altitude determined Differentially corrected Global Positioning System. D
Altitude accuracy .01 feet n/a
Altitude datum
North American Vertical Datum of 1988 NAVD88
Subbasin hydrologic unit
Lower Potomac 02070011
Drainage basin
n/a
Topographic setting
n/a
Flags for instruments at site YNNNYNNNNYNNNNNNYNNNNNNNNNNNNN n/a
Date of first construction
n/a
Date site established or inventoried n/a
Drainage area
24.0 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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logo for Maryland Department of Natural Resources, Maryland Geological Survey
Maryland Department of Natural Resources, Maryland Geological Survey
logo for USGS - Cooperative Matching Funds
USGS - Cooperative Matching Funds