U.S. DEPARTMENT OF COMMERCE
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National Ocean Service
Datums Page Page 1 of 7
Station ID: 9414509 PUBLICATION DATE: 09/27/2012
Name: DUMBARTON BRIDGE, SAN FRANCISCO BAY
CA
NOAA Chart: 18651 Latitude: 37° 30.4' N ( 37.50670)
USGS Quad: NEWARK Longitude: 122° 6.9' W (-122.11500)
To reach the tidal bench marks from I-80, take the Dumbarton Bridge West exit,
then turn left on Thorton Avenue West, follow the signs to the wildlife refuge
which will lead to a frontage road and then to the Old Dumbarton bridge. The
bench marks are along the roadway of the Old Dumbarton bridge. The tide gauge
was located at the SW end of the old State Road 84 bridge. Special use permit or
authorization is required to visit the bench marks or the station.
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 7
Station ID: 9414509 PUBLICATION DATE: 09/27/2012
Name: DUMBARTON BRIDGE, SAN FRANCISCO BAY
CA
NOAA Chart: 18651 Latitude: 37° 30.4' N ( 37.50670)
USGS Quad: NEWARK Longitude: 122° 6.9' W (-122.11500)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: U 553 1956
DESIGNATION: U 553
MONUMENTATION: Tidal Station disk VM#: 8150
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: HT0308
SETTING CLASSIFICATION: Concrete curb OPUS PID:
LATITUDE: 37° 30.4' N ( 37.50669) LONGITUDE: 122° 7.0' W (-122.11678)
The primary bench mark is a disk set in top of the concrete curb along the old
Dumbarton bridge, at the SW end, 9.14 m (30.0 ft) SW of the tide house, 3.51 m
(11.5 ft) SE of the centerline of the road, 0.30 m (1 ft) NE of the stairs
leading to fishing pier, and 0.25 m (0.8 ft) above the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 9414509 PUBLICATION DATE: 09/27/2012
Name: DUMBARTON BRIDGE, SAN FRANCISCO BAY
CA
NOAA Chart: 18651 Latitude: 37° 30.4' N ( 37.50670)
USGS Quad: NEWARK Longitude: 122° 6.9' W (-122.11500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: V 553 1956
DESIGNATION: V 553
MONUMENTATION: Tidal Station disk VM#: 8151
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: HT0309
SETTING CLASSIFICATION: Concrete curb OPUS PID:
LATITUDE: 37° 30.6' N ( 37.51003) LONGITUDE: 122° 6.7' W (-122.11178)
The bench mark is a disk set in top of the concrete curb over BENT 117 on the SE
side of old Dumbarton Bridge, 54.10 m (177.5 ft) SW of the NE end of the bridge,
5.10 m (16.7 ft) NE of a concrete bench, 3.50 m (11.5 ft) SE of the centerline
of the bridge, and 0.25 m (0.8 ft) above the road.
BENCH MARK STAMPING: 4509 H 1983
DESIGNATION: 941 4509 H
MONUMENTATION: Tidal Station disk VM#: 8154
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID#: DG6880
LATITUDE: 37° 30.7' N ( 37.51186) LONGITUDE: 122° 6.6' W (-122.10950)
The bench mark is a disk located on the south side of the road that leads to the
pier, 274.00 m (898.9 ft) NE of the shore end of the pier, 10.36 m (34.0 ft) SE
of the centerline of the road, 4.27 m (14.0 ft) east of the guard rail, and 0.12
m (0.4 ft) north of an orange witness post. The bench mark is set 9 cm (0.3 ft)
below ground, crimped to a galvanized rod driven to a depth of 14.63 m (48.0
ft), and encased in a 4-inch PVC pipe with black cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 9414509 PUBLICATION DATE: 09/27/2012
Name: DUMBARTON BRIDGE, SAN FRANCISCO BAY
CA
NOAA Chart: 18651 Latitude: 37° 30.4' N ( 37.50670)
USGS Quad: NEWARK Longitude: 122° 6.9' W (-122.11500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4509 K 1996
DESIGNATION: 941 4509 K
MONUMENTATION: Tidal Station disk VM#: 13327
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete curb OPUS PID:
LATITUDE: 37° 30.5' N ( 37.50833) LONGITUDE: 122° 6.9' W (-122.11450)
The bench mark is a disk set in top of a concrete curb of the old Dumbarton
Bridge, on the NE side of the road, 274.00 m (898.9 ft) NE of the SW end of the
bridge, 6.10 m (20.0 ft) west of the seventh wood bench from the shore end of
the pier, 0.30 m (1.0 ft) SE of the NW face of the bridge, and 0.25 m (0.8 ft)
above the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 9414509 PUBLICATION DATE: 09/27/2012
Name: DUMBARTON BRIDGE, SAN FRANCISCO BAY
CA
NOAA Chart: 18651 Latitude: 37° 30.4' N ( 37.50670)
USGS Quad: NEWARK Longitude: 122° 6.9' W (-122.11500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: SEA SURVEYOR #3 2005
DESIGNATION: SEA SURVEYOR #3
MONUMENTATION: Tidal Station disk VM#: 20201
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Concrete curb OPUS PID:
LATITUDE: 37° 30.4' N ( 37.50706) LONGITUDE: 122° 7.0' W (-122.11686)
The bench mark is a disk set in top of a concrete support leg for the Dumbarton
Bridge, on the center of the support leg, 77.2 m (253.3 ft) south of the
southern leg of PG&E electrical tower, 34.00 m (111.5 ft) north of the NW end of
the Old Dumbarton bridge, and 27.50 m (90.2 ft) NW of the USGS instrument shed.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 9414509 PUBLICATION DATE: 09/27/2012
Name: DUMBARTON BRIDGE, SAN FRANCISCO BAY
CA
NOAA Chart: 18651 Latitude: 37° 30.4' N ( 37.50670)
USGS Quad: NEWARK Longitude: 122° 6.9' W (-122.11500)
T I D A L D A T U M S
Tidal datums at DUMBARTON BRIDGE, SAN FRANCISCO BAY based on:
LENGTH OF SERIES: 5 MONTHS
TIME PERIOD: February 2011 and April thru July 2011
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9414750 ALAMEDA, SAN FRANCISCO BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 2.625
MEAN HIGH WATER MHW = 2.437
MEAN SEA LEVEL MSL = 1.427
MEAN TIDE LEVEL MTL = 1.410
MEAN LOW WATER MLW = 0.383
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
U 553 1956 7.310 4.873
V 553 1956 7.196 4.759
4509 H 1983 3.345 0.908
4509 K 1996 7.138 4.701
SEA SURVEYOR #3 2005 3.844 1.407
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 9414509 PUBLICATION DATE: 09/27/2012
Name: DUMBARTON BRIDGE, SAN FRANCISCO BAY
CA
NOAA Chart: 18651 Latitude: 37° 30.4' N ( 37.50670)
USGS Quad: NEWARK Longitude: 122° 6.9' W (-122.11500)
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.