U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 10
Station ID: 8594900 PUBLICATION DATE: 04/11/2018
Name: WASHINGTON, POTOMAC RIVER
DC
NOAA Chart: 12289 Latitude: 38° 52.4' N ( 38.87333)
USGS Quad: WASHINGTON WEST Longitude: 77° 1.3' W ( -77.02167)
To reach the tidal bench marks from where I-395 northbound splits, travel 1.0 km
(0.7 mi) along I-395 northbound to the Maine Avenue S.W. exit. Take the Maine
Avenue SW exit road for 0.3 km (0.2 mi) until it dead ends into Water Street
S.W. Turn SE onto Water Street, S.W. and proceed to the end of Water Street to
the Police and Fire Harbor Patrol Office at Pier 5. The bench marks are located
along Water Street, Maine Avenue, and Pier 5. The tide station is located at the
SW end of the pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4900 K 2010
DESIGNATION: 859 4900 K
MONUMENTATION: Tidal Station disk VM#: 19670
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID#: BBBY62
LATITUDE: 38° 52.3' N ( 38.87186) LONGITUDE: 77° 1.2' W ( -77.01936)
The primary bench mark is set flush in the south corner of the concrete seawall,
southwest of the titanic memorial, 17.97 m (59.0 ft) SSE of a 1.02 m (3.3 ft)
diameter round sewer manhole, 7.18 m (23.6 ft) SW of the foundation for the
human statue in the Titanic Memorial, 2.27 m (7.4 ft) NE of the SW corner of the
seawall, and 0.11 m (0.4 ft) higher than the sidewalk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 10
Station ID: 8594900 PUBLICATION DATE: 04/11/2018
Name: WASHINGTON, POTOMAC RIVER
DC
NOAA Chart: 12289 Latitude: 38° 52.4' N ( 38.87333)
USGS Quad: WASHINGTON WEST Longitude: 77° 1.3' W ( -77.02167)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 5 1973
DESIGNATION: 859 4900 TIDAL 5
MONUMENTATION: Tidal Station disk VM#: 459
AGENCY: National Ocean Survey (NOS) IDB PID#: HV9069
SETTING CLASSIFICATION: Concrete sea wall OPUS PID#: HV9069
LATITUDE: 38° 52.5' N ( 38.87500) LONGITUDE: 77° 1.2' W ( -77.02000)
The bench mark is a disk set in the concrete seawall at the northern inshore
corner of Pier 4, 33.72 m (110.6 ft) SW of the centerline of Water Street, 24.83
m (81.5 ft) SW of the first light pole NW of the Washington Boat Lines driveway
entrance, 3.63 m (11.9 ft) NW of the center of the NW gate entrance, 2.74 m (9.0
ft) north of the NW corner of the Spirit of Washington Boat Lines building, and
0.40 m (1.3 ft) NW of the first brick fence pillar NW of the NW gate.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 10
Station ID: 8594900 PUBLICATION DATE: 04/11/2018
Name: WASHINGTON, POTOMAC RIVER
DC
NOAA Chart: 12289 Latitude: 38° 52.4' N ( 38.87333)
USGS Quad: WASHINGTON WEST Longitude: 77° 1.3' W ( -77.02167)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: RV PIER 4
MONUMENTATION: Rivet VM#: 467
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: HV1983
SETTING CLASSIFICATION: Concrete pier deck OPUS PID:
LATITUDE: 38° 52.4' N ( 38.87331) LONGITUDE: 77° 1.2' W ( -77.02000)
The bench mark is a monel rivet set near the SW corner of the Spirit of
Washington Cruises loading dock at Pier 4, 2.80 m (9.2 ft) NNE of a bumper post
with a light, 0.52 m (1.7 ft) north of the most easterly of 9 bumper posts at
the SW end of the pier, and 0.20 m (0.7 ft) NW of the SE edge of the pier.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 10
Station ID: 8594900 PUBLICATION DATE: 04/11/2018
Name: WASHINGTON, POTOMAC RIVER
DC
NOAA Chart: 12289 Latitude: 38° 52.4' N ( 38.87333)
USGS Quad: WASHINGTON WEST Longitude: 77° 1.3' W ( -77.02167)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Z 1923
DESIGNATION: Z
MONUMENTATION: Bench Mark disk VM#: 14009
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: HV1979
SETTING CLASSIFICATION: 3-Story brick building OPUS PID:
LATITUDE: 38° 52.3' N ( 38.87192) LONGITUDE: 77° 1.0' W ( -77.01742)
The bench mark is a disk set in the water table on the north side of the
headquarters building at U.S. Army Fort Lesley J. McNair Military District of
Washington, at the intersection of P Street SW and 4th Street SW, 13.01 m (42.7
ft) west of the NE corner of the building, 13.01 m (42.7 ft) east of the
extended centerline of 4th Street SW, 7.10 m (23.3 ft) south of the south curb
of P Street SW, and 1.19 m (3.9 ft) above street level.
BENCH MARK STAMPING: 4900 J 2007
DESIGNATION: 859 4900 J
MONUMENTATION: Tidal Station disk VM#: 18500
AGENCY: IDB PID#:
SETTING CLASSIFICATION: PIER OPUS PID:
LATITUDE: 38° 52.4' N ( 38.87331) LONGITUDE: 77° 1.3' W ( -77.02169)
In Washington DC, at the end of Water Street, the bench mark is set in the
concrete deck along the SW side of the DC Police and Fire Harbor Patrol Pier 5,
7.88 m (25.85 ft) east of the centerline of a bollard on the SW end of the pier,
2.10 m (6.89 ft) SW of centerline of a bollard on the SE end of the pier, 1.14 m
(3.74 ft) NW of the SE retaining wall, set flush with pier deck next Aquatrak
well and gauge house.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 10
Station ID: 8594900 PUBLICATION DATE: 04/11/2018
Name: WASHINGTON, POTOMAC RIVER
DC
NOAA Chart: 12289 Latitude: 38° 52.4' N ( 38.87333)
USGS Quad: WASHINGTON WEST Longitude: 77° 1.3' W ( -77.02167)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4900 L 2014
DESIGNATION: 859 4900 L
MONUMENTATION: Bench Mark disk VM#: 21482
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: Concrete foundatoin OPUS PID:
LATITUDE: 38° 52.4' N ( 38.87389) LONGITUDE: 77° 1.3' W ( -77.02111)
The bench mark is 24.85 m (81.5 ft) east of the northwest corner of the police
building, 7.74 m (25.4 ft) south of the north face of the concrete bulkhead,
2.95 m (9.7 ft) west of the centerline of the garage/bay door on the north face
of the building, 0.320 m (1.0 ft) north of the northern face of the building.
BENCH MARK STAMPING: 4900 M 2014
DESIGNATION: 859 4900 M
MONUMENTATION: Bench Mark disk VM#: 21483
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: Concrete pad OPUS PID:
LATITUDE: 38° 52.4' N ( 38.87381) LONGITUDE: 77° 1.2' W ( -77.02031)
The bench mark is 36.20 m (118.8 ft) south of the southeast corner of the police
building, 8.16 m (26.8 ft) east of the western face of the concrete seawall
along the Anacostia Riverwalk trail, 4.150 m (13.6 ft) west-southwest of the
concrete light pole along the Riverwalk trail, and is a disk set in a concrete
pad, 0.280 m (0.9 ft) above the sidewalk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 10
Station ID: 8594900 PUBLICATION DATE: 04/11/2018
Name: WASHINGTON, POTOMAC RIVER
DC
NOAA Chart: 12289 Latitude: 38° 52.4' N ( 38.87333)
USGS Quad: WASHINGTON WEST Longitude: 77° 1.3' W ( -77.02167)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4900 N 2014
DESIGNATION: 859 4900 N
MONUMENTATION: Bench Mark disk VM#: 21484
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 38° 52.3' N ( 38.87244) LONGITUDE: 77° 1.2' W ( -77.01972)
The bench mark is 68.78 m (225.7 ft) north of the southwest corner of the
Riverwalk sidewalk along the river, 4.58 m (15.0 ft) west of the centerline of
the Riverwalk trail, 4.56 m (15.0 ft) south of the sixth tree north of the south
end of the large statue, 0.520 m (1.7 ft) east of the west face of concrete
seawall, and is a disk set in concrete retaining wall flush with the surface.
BENCH MARK STAMPING: 4900 P 2016
DESIGNATION: 859 4900 P
MONUMENTATION: Bench Mark disk VM#: 21951
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 38° 52.4' N ( 38.87319) LONGITUDE: 77° 1.2' W ( -77.02014)
The bench mark is set atop a massive seawall along the Potomac River. The disc
is 95.8 m (314.3 ft) south of the south gate near the entrance to the police and
fire harbor rescue on Pier 5, 20.4 m (66.9 ft) SW of the SW corner of a concrete
knee high wall located near park benches outside of a 10 story apartment
building, and .5 m (1.6 ft) east of the edge of the seawall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 10
Station ID: 8594900 PUBLICATION DATE: 04/11/2018
Name: WASHINGTON, POTOMAC RIVER
DC
NOAA Chart: 12289 Latitude: 38° 52.4' N ( 38.87333)
USGS Quad: WASHINGTON WEST Longitude: 77° 1.3' W ( -77.02167)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4900 Q 2017
DESIGNATION: 859 4900 Q
MONUMENTATION: Vertical Control disk VM#: 22351
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 38° 52.5' N ( 38.87494) LONGITUDE: 77° 1.3' W ( -77.02094)
The bench mark is a disk located at the southern inshore corner of pier 4, 67.8m
(222.4 ft) North of the centerline of the police station entrance leading to the
tidal station, 4.68m (15.4 ft) south of the first brick fence pillar SE of the
building, and 0.2m (0.7 ft) east of the face of the seawall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 10
Station ID: 8594900 PUBLICATION DATE: 04/11/2018
Name: WASHINGTON, POTOMAC RIVER
DC
NOAA Chart: 12289 Latitude: 38° 52.4' N ( 38.87333)
USGS Quad: WASHINGTON WEST Longitude: 77° 1.3' W ( -77.02167)
T I D A L D A T U M S
Tidal datums at WASHINGTON, POTOMAC RIVER based on:
LENGTH OF SERIES: 19 YEARS
TIME PERIOD: January 1983 - December 2001
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION:
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/17/1942) = 3.368
MEAN HIGHER HIGH WATER MHHW = 0.965
MEAN HIGH WATER MHW = 0.896
MEAN SEA LEVEL MSL = 0.472
MEAN TIDE LEVEL MTL = 0.471
North American Vertical Datum NAVD88 = 0.425
MEAN LOW WATER MLW = 0.047
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (02/26/1967) = -1.539
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
4900 K 2010 3.281 2.384
NO 5 1973 2.733 1.837
RV PIER 4 2.750 1.854
Z 1923 7.025 6.129
4900 J 2007 2.641 1.745
4900 L 2014 2.749 1.853
4900 M 2014 3.428 2.532
4900 N 2014 2.853 1.957
4900 P 2016 2.869 1.973
4900 Q 2017 2.968 2.072
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 10
Station ID: 8594900 PUBLICATION DATE: 04/11/2018
Name: WASHINGTON, POTOMAC RIVER
DC
NOAA Chart: 12289 Latitude: 38° 52.4' N ( 38.87333)
USGS Quad: WASHINGTON WEST Longitude: 77° 1.3' W ( -77.02167)
Foot Notes:
Bench marks 4900 Q 2017 and RV PIER 4 are based on one differential leveling
connection and do not meet the quality control standards of the NOS. Therefore,
caution should be used when deriving elevations for these marks.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 10 of 10
Station ID: 8594900 PUBLICATION DATE: 04/11/2018
Name: WASHINGTON, POTOMAC RIVER
DC
NOAA Chart: 12289 Latitude: 38° 52.4' N ( 38.87333)
USGS Quad: WASHINGTON WEST Longitude: 77° 1.3' W ( -77.02167)
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.