U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 02/20/1988
Station ID: 9415111 SUPERCEDED DATE: 04/21/2003
Name: BENICIA, CARQUINEZ STRAIT
CALIFORNIA
NOAA Chart: 18657 Latitude: 38° 2.6' N
USGS Quad: BENICIA Longitude: 122° 7.8' W
To reach the tidal bench marks from Interstate 780 in Benicia, take the 5th
Street exit and proceed south for 2 blocks, turn left on M Street, then right on
Grant Street at Port of Benicia. The bench marks are located at Port of Benicia
Wharf and along Bayshore Road. The tide gage and staff were located on the east
side of the Wharf.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 9 1948
MONUMENTATION: Survey Disk VM#: 8554
AGENCY: PID#: JT0141
SETTING CLASSIFICATION: Sea Wall
The bench mark is at the junction of the sea wall, and the wooden handrail which
follows the road and railroad tracks to shore, 42 feet (13 m) north of the
easternmost of two bollards, 39 feet (12 m) south of the north end of the sea
wall, 28.3 feet (8.6 m) SE of a fire hydrant protected by red pipes, and 3 feet
(1 m) north of the south end of the sea wall.
BENCH MARK STAMPING: D 790 1946
MONUMENTATION: Survey Disk VM#: 8553
AGENCY: PID#: JT0134
SETTING CLASSIFICATION: Concrete Base
The bench mark is set in the top of a concrete base supporting the fourth steel
leg east of the west end of the Southern Pacific railroad bridge, 75 feet (23 m)
east of the centerline of Bayshore Drive, about 20 feet (6 m) west of the
shoreline, 0.5 foot (0.2 m) west of the east edge of the concrete base, and 1.5
feet (0.5 m) above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 02/20/1988
Station ID: 9415111 SUPERCEDED DATE: 04/21/2003
Name: BENICIA, CARQUINEZ STRAIT
CALIFORNIA
NOAA Chart: 18657 Latitude: 38° 2.6' N
USGS Quad: BENICIA Longitude: 122° 7.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 10 1948
MONUMENTATION: Survey Disk VM#: 8555
AGENCY: PID#: JT0139
SETTING CLASSIFICATION: Concrete Apron
The bench mark is set in the SW corner of a concrete apron for a toxic acid work
area, 23 feet (7 m) NW of the centerline of Bayshore Drive, 17 feet (5 m) SW of
the center of the concrete apron, 6 feet (2 m) north of the south end of a curb,
and level with the road.
BENCH MARK STAMPING: 5111 D 1976
MONUMENTATION: Survey Disk VM#: 8556
AGENCY: PID:
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is located near the northeast end of Port of Benicia Wharf at
Gate #23, 177 feet (54 m) south of the centerline of Bayshore Road, 147.3 feet
(44.9 m) NW of the corner of Building 54, 14.9 feet (4.5 m) WSW of the center of
Gate #23, 2.3 feet (0.7 m) south of a fire hydrant, and 2 feet (1 m) SW of a
witness post and sign. The bench mark is crimped to a copper-clad steel rod
driven 15 feet (5 m) to refusal.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 02/20/1988
Station ID: 9415111 SUPERCEDED DATE: 04/21/2003
Name: BENICIA, CARQUINEZ STRAIT
CALIFORNIA
NOAA Chart: 18657 Latitude: 38° 2.6' N
USGS Quad: BENICIA Longitude: 122° 7.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5111 E 1976
MONUMENTATION: Survey Disk VM#: 8557
AGENCY: PID:
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is located on the northern side of Bayshore Road between Oak Road
and the Benicia-Martinez highway bridge, 202 feet (62 m) NW of the intersection
of Bayshore and Oak Roads, 67.5 feet (20.6 m) north of the northernmost rail of
three railroad tracks, 47.6 feet (14.5 m) NW of the centerline of Bayshore Road,
3.5 feet (1.1 m) from telephone pole KOPPERS FP 70, W6, 4-50, and 1.5 feet (0.5
m) SE of a fence surrounding the Toyota storage lot. The bench mark is 0.8 foot
(0.2 m) above the ground, crimped to a copper-clad steel rod driven 31 feet (9
m) to refusal and encased in a PVC pipe.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 02/20/1988
Station ID: 9415111 SUPERCEDED DATE: 04/21/2003
Name: BENICIA, CARQUINEZ STRAIT
CALIFORNIA
NOAA Chart: 18657 Latitude: 38° 2.6' N
USGS Quad: BENICIA Longitude: 122° 7.8' W
T I D A L D A T U M S
Tidal datums at BENICIA, CARQUINEZ STRAIT based on:
LENGTH OF SERIES: 5 YEARS
TIME PERIOD: 1977-1981
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 9414290 SAN FRANCISCO
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (02/21/1980) = 7.47
MEAN HIGHER HIGH WATER MHHW = 5.17
MEAN HIGH WATER MHW = 4.66
MEAN TIDE LEVEL MTL = 2.75
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 2.10
MEAN LOW WATER MLW = 0.85
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (05/06/1981) = -1.04
* NGVD reference based on elevations published in Quad 381222, 1974, and NOS
leveling of 1982.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
9 1948 15.00 10.34
D 790 1946 12.93 8.27
10 1948 11.11 6.45
5111 D 1976 10.19 5.53
5111 E 1976 11.78 7.12
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 02/20/1988
Station ID: 9415111 SUPERCEDED DATE: 04/21/2003
Name: BENICIA, CARQUINEZ STRAIT
CALIFORNIA
NOAA Chart: 18657 Latitude: 38° 2.6' N
USGS Quad: BENICIA Longitude: 122° 7.8' W
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 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.