U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8579997 PUBLICATION DATE: 09/17/2003
Name: BLADENSBURG, ANACOSTIA RIVER
MD
NOAA Chart: 12289 Latitude: 38° 56.0' N ( 38.93330)
USGS Quad: WASHINGTON EAST Longitude: 76° 56.3' W ( -76.93830)
To reach the tidal bench marks from the intersection of State Road 450
(Annapolis Road) and State Road 202 (Landover Road) in Bladensburg, proceed west
on Annapolis Rd 1.1 km (0.7 mi), and turn south into the entrance to the
Historic Bladensburg Waterfront - Anacostia River Park, then proceed 0.6 km (0.4
mi) south through the park to the Department of Parks and Recreation Warehouse.
The bench marks are located along the historic waterfront area and along
Annapolis Road. The gage and shelter were located at the boat hoist slip near
the south end of the marina bulkhead.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 3 TIDAL 1992
DESIGNATION: 857 9997 TIDAL 3
MONUMENTATION: Survey disk VM#: 12726
AGENCY: US Army Corps of Engineers (USE) IDB PID#:
SETTING CLASSIFICATION: Concrete filled pipe OPUS PID:
LATITUDE: 38° 56.0' N ( 38.93330) LONGITUDE: 76° 56.3' W ( -76.93830)
The primary bench mark is a disk set in a concrete filled 4-inch PVC pipe which
is part of an irregular poured mass of concrete of unspecified depth and
dimensions, located on the Anacostia River Park property, near the public boat
ramp, 0.2 km (0.1 mi) south of Annapolis Road, 85.01 m (278.9 ft) west of a fire
hydrant, 35.50 m (116.5 ft) NE of the western most 7-ft chainlink fence corner
post, 6.90 m (22.6 ft) south of the west corner of the boat ramp, 0.23 m (0.8
ft) west of a witness post, and flush with the ground surface.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8579997 PUBLICATION DATE: 09/17/2003
Name: BLADENSBURG, ANACOSTIA RIVER
MD
NOAA Chart: 12289 Latitude: 38° 56.0' N ( 38.93330)
USGS Quad: WASHINGTON EAST Longitude: 76° 56.3' W ( -76.93830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9997 A 1995
DESIGNATION: 857 9997 A
MONUMENTATION: Tidal Station disk VM#: 12727
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete manhole cover OPUS PID:
LATITUDE: 38° 56.0' N ( 38.93330) LONGITUDE: 76° 56.3' W ( -76.93830)
The bench mark is a disk set in the NW corner of a 2.5 x 2.5 m (8.2 x 8.2 ft)
concrete structure with manhole cover on the Anacostia River Park property, near
the Department of Parks and Recreation warehouse, 0.6 km (0.4 mi) south of
Annapolis Road, 34.50 m (113.2 ft) east of the river bulkhead, 13.09 m (43.0 ft)
NE of the NE corner of restroom building attached to the north side of the
warehouse, 4.30 m (14.0 ft) south of the southern most lightpole of nine along
park drive, 0.25 m (0.8 ft) SE of NW corner of concrete structure, and 0.20 m
(0.6 ft) above grade.
BENCH MARK STAMPING: 9997 B 1995
MONUMENTATION: Tidal Station disk VM#: 12728
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 38° 56.0' N ( 38.93330) LONGITUDE: 76° 56.3' W ( -76.93830)
The bench mark is a disk set flush in a concrete retaining wall at the
Bladensburg Pumping Station, near the entrance drive to the Anacostia River
Park, 65.71 m (215.6 ft) SW of flood control culvert on the south side of
Annapolis Road, 36.45 m (119.6 ft) west of the centerline of entrance drive to
the park, 3.00 m (9.8 ft) SE of the centerline of a flood control ditch, 0.15 m
(0.6 ft) west of the east corner of the retaining wall, and 0.3 m (1 ft) above
the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8579997 PUBLICATION DATE: 09/17/2003
Name: BLADENSBURG, ANACOSTIA RIVER
MD
NOAA Chart: 12289 Latitude: 38° 56.0' N ( 38.93330)
USGS Quad: WASHINGTON EAST Longitude: 76° 56.3' W ( -76.93830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9997 C 1995
DESIGNATION: 857 9997 C
MONUMENTATION: Tidal Station disk VM#: 12729
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 38° 56.0' N ( 38.93330) LONGITUDE: 76° 56.3' W ( -76.93830)
The bench mark is a disk located on the Anacostia River Park property, just
north of a creek bank near the Department of Parks and Recreation warehouse, 0.7
km (0.4 mi) south of Annapolis Rd., 53.71 m (176.2 ft) SE of south corner of the
boat hoist slip, 33.30 m (109.3 ft) south of the SE corner of warehouse, and
0.45 m (1.5 ft) NE of a witness post. The bench mark is crimped to a stainless
steel rod driven 8.1 m (26.5 ft) to refusal, and encased in a 5-inch PVC pipe
with concrete kickblock.
BENCH MARK STAMPING: 5430 T.S.
MONUMENTATION: Survey disk VM#: 12730
AGENCY: Washington Suburban Sanitary Commission
(WSSC) IDB PID#:
SETTING CLASSIFICATION: Concrete walk OPUS PID#: BBDN74
LATITUDE: 38° 56.0' N ( 38.93330) LONGITUDE: 76° 56.3' W ( -76.93830)
The bench mark is a disk set flush in the concrete walk on the SW end of the
Anacostia River bridge along Annapolis Road, 0.4 km (0.25 mi) west of the
intersection of 46th Street and Annapolis Road, 32.19 m (105.6 ft) NE of power
pole #815402-9648, 10.18 m (33.4 ft) NW of centerline of Annapolis Road, 1.50 m
(4.9 ft) east of the west corner of bridge, and 0.20 m (0.7 ft) above the
highway surface.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8579997 PUBLICATION DATE: 09/17/2003
Name: BLADENSBURG, ANACOSTIA RIVER
MD
NOAA Chart: 12289 Latitude: 38° 56.0' N ( 38.93330)
USGS Quad: WASHINGTON EAST Longitude: 76° 56.3' W ( -76.93830)
T I D A L D A T U M S
Tidal datums at BLADENSBURG, ANACOSTIA RIVER based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: April 1996 - July 1996
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 = 1.019
MEAN HIGH WATER MHW = 0.950
MEAN TIDE LEVEL MTL = 0.500
MEAN SEA LEVEL MSL = 0.495
MEAN LOW WATER MLW = 0.051
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 3 TIDAL 1992 1.763 0.813
9997 A 1995 4.071 3.121
9997 B 1995 3.622 2.672
9997 C 1995 2.832 1.882
5430 T.S. 7.932 6.982
Foot Notes:
Bench marks 9997 B 1995 and 5430 T.S. 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 5 of 5
Station ID: 8579997 PUBLICATION DATE: 09/17/2003
Name: BLADENSBURG, ANACOSTIA RIVER
MD
NOAA Chart: 12289 Latitude: 38° 56.0' N ( 38.93330)
USGS Quad: WASHINGTON EAST Longitude: 76° 56.3' W ( -76.93830)
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.