U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8593005 PUBLICATION DATE: 09/30/2010
Name: WASHINGTON NAVY YARD,D.C.
DC
NOAA Chart: 12285 Latitude: 38° 52.3' N ( 38.87170)
USGS Quad: ANACOSTIA Longitude: 76° 59.7' W ( -76.99500)
To reach the tidal bench marks from the intersection of South Capitol Street and
M Street in the District of Columbia, proceed east on M Street to the Parsons
Avenue entrance (across from 9th Street SE) to the Washington Navy Yard, turn
right and continue south on Parsons Avenue, then turn right on N Street and left
on Harwood Street, and continue south past the Navy Museum to the waterfront.
The bench marks are located on the Navy Yard property. The tide gage was located
at the foot of the easternmost pier.
T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8593005 PUBLICATION DATE: 09/30/2010
Name: WASHINGTON NAVY YARD,D.C.
DC
NOAA Chart: 12285 Latitude: 38° 52.3' N ( 38.87170)
USGS Quad: ANACOSTIA Longitude: 76° 59.7' W ( -76.99500)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: G 2
DESIGNATION: G 2
MONUMENTATION: Bolt VM#: 12744
AGENCY: CGS IDB PID#: HV1399
SETTING CLASSIFICATION: Brass bolt in granite foundation OPUS PID:
LATITUDE: 38° 52.3' N ( 38.87170) LONGITUDE: 76° 59.7' W ( -76.99500)
The bench mark is the highest point of a barrel-shaped knob on the projecting
end of a brass bolt, the exposed end of which is stamped G 2, in SE Washington
on the grounds of the Naval Gun Factory, on Paulding Street, at the SW corner of
building 76 (museum), 12.20 m (40.0 ft) west of the south entrance to the
museum, 0.12 m (0.4 ft) east of the corner, and in the south side of the granite
foundation.
BENCH MARK STAMPING: NO 101 1940
DESIGNATION: 101 WNY RESET 1955
MONUMENTATION: Survey disk VM#: 12742
AGENCY: US Army Corps of Engineers (USE) IDB PID#: HV1402
SETTING CLASSIFICATION: Brick and concrete retaining wall OPUS PID:
LATITUDE: 38° 52.3' N ( 38.87170) LONGITUDE: 76° 59.7' W ( -76.99500)
The bench mark is a disk in the top of a brick retaining wall (old yard wall),
in SE Washington on the grounds of the Naval Gun Factory, on Parsons Avenue,
south of building 101, east of the NE corner of Building 130, and 0.30 m (1.0
ft) south of the north end of the wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8593005 PUBLICATION DATE: 09/30/2010
Name: WASHINGTON NAVY YARD,D.C.
DC
NOAA Chart: 12285 Latitude: 38° 52.3' N ( 38.87170)
USGS Quad: ANACOSTIA Longitude: 76° 59.7' W ( -76.99500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 2 1940
DESIGNATION: 2 WNY
MONUMENTATION: Survey disk VM#: 12743
AGENCY: US Army Corps of Engineers (USE) IDB PID#: HV1397
SETTING CLASSIFICATION: Concrete doorsill OPUS PID:
LATITUDE: 38° 52.3' N ( 38.87170) LONGITUDE: 76° 59.7' W ( -76.99500)
The bench mark is a disk set on the concrete doorsill of the east door on the
south side of building 142, in SE Washington on the grounds of the Naval Gun
Factory, at the NW corner of the intersection of Patterson Avenue and Sicard
Street, 0.24 m (0.8 ft) south of the door, and 0.06 m (0.2 ft) from the west
edge of the doorway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8593005 PUBLICATION DATE: 09/30/2010
Name: WASHINGTON NAVY YARD,D.C.
DC
NOAA Chart: 12285 Latitude: 38° 52.3' N ( 38.87170)
USGS Quad: ANACOSTIA Longitude: 76° 59.7' W ( -76.99500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: X
DESIGNATION: X
MONUMENTATION: Bench Mark disk VM#: 12745
AGENCY: CGS IDB PID#: HV1400
SETTING CLASSIFICATION: Granite doorsill OPUS PID:
LATITUDE: 38° 52.3' N ( 38.87170) LONGITUDE: 76° 59.7' W ( -76.99500)
The bench mark is a disk set in the granite doorsill of the first doorway from
the south end of building 108, on the west side of the building, in SE
Washington on the grounds of the Naval Gun Factory, near the NE corner of the
intersection of Dahlgren Avenue and Montgomery Square, 0.27 m (0.9 ft) west of
the door, and 0.09 m (0.3 ft) north of the south end of the doorway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8593005 PUBLICATION DATE: 09/30/2010
Name: WASHINGTON NAVY YARD,D.C.
DC
NOAA Chart: 12285 Latitude: 38° 52.3' N ( 38.87170)
USGS Quad: ANACOSTIA Longitude: 76° 59.7' W ( -76.99500)
T I D A L D A T U M S
Tidal datums at WASHINGTON NAVY YARD,D.C. based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: August 1995 - October 1995
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8594900 WASHINGTON, POTOMAC RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.976
MEAN HIGH WATER MHW = 0.905
MEAN TIDE LEVEL MTL = 0.475
MEAN SEA LEVEL MSL = 0.475
North American Vertical Datum NAVD88 = 0.455
MEAN LOW WATER MLW = 0.047
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
G 2 3.131 2.226
NO 101 1940 4.615 3.710
NO 2 1940 2.296 1.391
X 3.798 2.893
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8593005 PUBLICATION DATE: 09/30/2010
Name: WASHINGTON NAVY YARD,D.C.
DC
NOAA Chart: 12285 Latitude: 38° 52.3' N ( 38.87170)
USGS Quad: ANACOSTIA Longitude: 76° 59.7' W ( -76.99500)
D E F I N I T I O N S
Mean Sea Level (MSL) is a tidal datum determined over a 19-year National Tidal
Datum Epoch. It pertains to local mean sea level and should not be confused
with the fixed datums of North American Vertical Datum of 1988 (NAVD88).
NAVD88 is a fixed datum derived from a simultaneous, least squares, minimum
constraint adjustment of Canadian/Mexican/United States leveling observations.
Local mean sea level observed at Father Point/Rimouski, Canada was held fixed as
the single initial constraint. NAVD88 replaces NGVD29 as the national
standard geodetic reference for heights. Bench mark elevations relative to
NAVD88 are available from NGS through the World Wide Web at
National Geodetic Survey.
NGVD29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded. NGVD29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads. NGVD29 was originally derived from a general
adjustment of the first-order leveling networks of the U.S. and Canada after
holding mean sea level observed at 26 long term tide stations as fixed.
Numerous local and wide-spread adjustments have been made since establishment in
1929. Bench mark elevations relative to NGVD29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at
National Geodetic Survey.
NAVD88 and NGVD29 are fixed geodetic datums whose elevation relationships to
local MSL and other tidal datums may not be consistent from one location to
another.
The Vertical Mark Number (VM#) and PID# shown on the bench mark sheet are unique
identifiers for bench marks in the tidal and geodetic databases, respectively.
Each bench mark in either database has a single, unique VM# and/or PID# assigned.
Where both VM# and PID# are indicated, both tidal and geodetic elevations are
available for the bench mark listed. The NGS's Integrated Data Base (IDB PID)
provides geodetic datum based on traditionally leveled and bluebooked ties to
the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/.
The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based
on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/.
The NAVD88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD88 elevations.
The NAVD88 elevation relationship shown in the table is derived from an average
of several bench mark elevations relative to tide station datum. As a result of
this averaging, NAVD88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD88 elevations listed for
each bench mark in the NGS database.