Bench Mark Sheet for 9414523, Redwood City CA

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  7

                                                                                
Station ID: 9414523                         PUBLICATION DATE:  06/22/2020
Name:       REDWOOD CITY, WHARF 5, S. F. BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 30.4' N (  37.50670)
USGS Quad:  REDWOOD POINT                   Longitude: 122° 12.6' W (-122.21000)


To reach the tidal bench marks from U.S. Highway 101 exit at Seaport Boulevard
to Port of Redwood City, go 1.6 km (1 mi) NE of the freeway on the Seaport
Boulevard to the entrance gate to Wharf No 5 near the SW end of the port.  The
bench marks are in the general vicinity along the coast.  The tide gage is
located on the pier.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  4508 A 1997
                         DESIGNATION:          941 4508 A

MONUMENTATION:           Tidal Station disk                    VM#:        13852
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID#: BBBF96
LATITUDE:   37° 30.5' N (  37.50861)          LONGITUDE: 122° 12.6' W (-122.21033)


The primary bench mark is a disk located at the S bend dirt area along Kerkner
Road, west of post office, 8 m (26 ft) east of centerline of the N/S running
segment of Herkner Road, 5.30 m (17.4 ft) SW of center of railroad tracks, 4.91
m (16.1 ft)  NE of a fence with witness sign attached.  The bench mark is set 
0.20 m (0.7 ft) below grade, crimped to a stainless steel rod driven 15.5 m (51
ft) to refusal and encased in a 6 inch (15 cm) PVC pipe with a concrete kick
block.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 9414523                         PUBLICATION DATE:  06/22/2020
Name:       REDWOOD CITY, WHARF 5, S. F. BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 30.4' N (  37.50670)
USGS Quad:  REDWOOD POINT                   Longitude: 122° 12.6' W (-122.21000)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  4508 B 1997
                         DESIGNATION:          941 4508 B

MONUMENTATION:           Tidal Station disk                    VM#:        13853
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   37° 30.4' N (  37.50733)          LONGITUDE: 122° 12.6' W (-122.20925)


The bench mark is a disk located at the SW corner of the intersection of Seaport
Boulevard and Herkner Road, S of the post office, 20.70 m (67.9 ft) W of center
of Seaport Boulevard, 5.70 m (18.7 ft) W of center of railroad tracks, 4.39 m
(14.4 ft) S of  the SE corner of the westernmost of two vault boxes, 2.59 m (8.5
ft) slope distance E of the top of a metal witness sign on a chain link fence, 2
m (7 ft) E of a chain link fence with witness sign attached and 0.33 m (1.1 ft)
E of an orange fiberglass witness post. The bench mark is set  0.40 m (1.3 ft)
below ground level, and crimped to the top of a rod driven 18.3 m (60 ft) to
refusal.



                         BENCH MARK STAMPING:  4508 C 1997
                         DESIGNATION:          941 4508 C

MONUMENTATION:           Tidal Station disk                    VM#:        13854
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AH7470
SETTING CLASSIFICATION:  Concrete pad                          OPUS PID#: AH7470
LATITUDE:   37° 30.5' N (  37.50797)          LONGITUDE: 122° 12.7' W (-122.21086)


The bench mark is a disk set in the SE corner of a 1.35 m x 1.35 m (4.4 ft x 4.4
ft) concrete block supporting a bollard located between Wharfs 4 and 5 at the
Port of Redwood City, 15.20 m (49.9 ft) W of junction of two railroad tracks,
10.12 m (33.2 ft) E of the concrete breakwater, 5.48 m (18.0 ft) north of a fire
hydrant with four yellow guard posts, and 0.50 m (1.6 ft) above ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  7

                                                                                
Station ID: 9414523                         PUBLICATION DATE:  06/22/2020
Name:       REDWOOD CITY, WHARF 5, S. F. BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 30.4' N (  37.50670)
USGS Quad:  REDWOOD POINT                   Longitude: 122° 12.6' W (-122.21000)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  WHARF 4 1985
                         DESIGNATION:          941 4523 WHARF 4

MONUMENTATION:           Bench Mark disk                       VM#:        13856
AGENCY:                  US Geological Survey (USGS)           IDB PID:         
SETTING CLASSIFICATION:  Sea wall                              OPUS PID:        
LATITUDE:   37° 30.6' N (  37.50939)          LONGITUDE: 122° 12.7' W (-122.21167)


The bench mark is a disk set into the seaward bullrail on the N end of the
catwalk leading to the S dolphin on Wharf 4, 5.80 m (19.0 ft) S of high voltage
box "E2", 2.20 m (7.2 ft) S of the second southernmost bollard, 1.70 m (5.6 ft)
from W wharf face, and 0.30 m (1.0 ft) above wharf deck.



                         BENCH MARK STAMPING:  4508 T 1998
                         DESIGNATION:          941 4508 T

MONUMENTATION:           Tidal Station disk                    VM#:        14824
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Curb                                  OPUS PID:        
LATITUDE:   37° 30.4' N (  37.50739)          LONGITUDE: 122° 12.7' W (-122.21125)


The bench mark is a disk set in the S curb of the N ramp leading to Wharf 5 at
the Port of Redwood City, 14.60 m (47.9 ft) W of a light pole leading to the
pier, 10.0 m (32.8 ft) NW of SE end of curb, and 4.6 m (15.1 ft) S of center of
ramp.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  7

                                                                                
Station ID: 9414523                         PUBLICATION DATE:  06/22/2020
Name:       REDWOOD CITY, WHARF 5, S. F. BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 30.4' N (  37.50670)
USGS Quad:  REDWOOD POINT                   Longitude: 122° 12.6' W (-122.21000)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  4508 U 1998
                         DESIGNATION:          941 4508 U

MONUMENTATION:           Tidal Station disk                    VM#:        14825
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Sea wall                              OPUS PID:        
LATITUDE:   37° 30.5' N (  37.50867)          LONGITUDE: 122° 12.7' W (-122.21100)


The bench mark is a disk set in a sea wall near a boat ramp at the Port of
Redwood City between Wharfs 4 and 5, 15.24 m (50.0 ft) W of center of road
leading to the Wharf 4, 5.50 m (18.0 ft) E of center of boat ramp, and 4.90 m
(16.1 ft) S of the N end of the sea wall.



                         BENCH MARK STAMPING:  4523 A 2009
                         DESIGNATION:          945 4523 A

MONUMENTATION:           Metal Rod                             VM#:        19575
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   37° 30.5' N (  37.50786)          LONGITUDE: 122° 12.6' W (-122.20942)


The benchmark is set on the S side of Herkner Road, 20.8 m (68.2 ft) E of the
railroad switch along the S side of Hernker Road, 5.48 m (18.0 ft) S of the
center of Herkner Road, 3.0 m (9.8 ft) N of the center of the Port of Redwood
City railroad tracks, and 0.17 m (0.6 ft) N of the orange NOAA witness marker.
The bench mark is driven 17.1 m (56 ft) to refusal, encased in a 6-inch NOS logo
cap.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  7

                                                                                
Station ID: 9414523                         PUBLICATION DATE:  06/22/2020
Name:       REDWOOD CITY, WHARF 5, S. F. BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 30.4' N (  37.50670)
USGS Quad:  REDWOOD POINT                   Longitude: 122° 12.6' W (-122.21000)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  4523 B 2015
                         DESIGNATION:          941 4523 B

MONUMENTATION:           Tidal Station disk                    VM#:        21819
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Power pole foundation                 OPUS PID:        
LATITUDE:   37° 30.4' N (  37.50672)          LONGITUDE: 122° 12.6' W (-122.20917)


The bench mark is a NOS disk set in the SE corner of the concrete foundation of
a large metal power pole, # 0-8 40871287 between frontage road and seaport
boulevard, S of the entrance to port of redwood city, located 5.85 m (19.2 ft) W
of centerline of Frontage Road, 1.08 m (3.5 ft) N of S side of foundation, 0.75
m (2.5 ft) SE of power pole.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  7

                                                                                
Station ID: 9414523                         PUBLICATION DATE:  06/22/2020
Name:       REDWOOD CITY, WHARF 5, S. F. BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 30.4' N (  37.50670)
USGS Quad:  REDWOOD POINT                   Longitude: 122° 12.6' W (-122.21000)


                            T I D A L   D A T U M S 


Tidal datums at REDWOOD CITY, WHARF 5, S. F. BAY based on:

     LENGTH OF SERIES:      21 YEARS
     TIME PERIOD:           October 1997 - September 2018
     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:

     HIGHEST OBSERVED WATER LEVEL (12/03/1983)         =  3.289
     MEAN HIGHER HIGH WATER                     MHHW   =  2.500
     MEAN HIGH WATER                            MHW    =  2.307
     MEAN SEA LEVEL                             MSL    =  1.342
     MEAN TIDE LEVEL                            MTL    =  1.336
     MEAN LOW WATER                             MLW    =  0.365
     North American Vertical Datum              NAVD88 =  0.360
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/11/2009)         = -0.848

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     4508 A 1997                                 2.787    0.480
     4508 B 1997                                 2.048   -0.259
     4508 C 1997                                 3.882    1.575
     WHARF 4 1985                                4.618    2.311
     4508 T 1998                                 4.109    1.802
     4508 U 1998                                 3.535    1.228
     4523 A 2009                                 2.328    0.021
     4523 B 2015                                 2.256   -0.051


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  7

                                                                                
Station ID: 9414523                         PUBLICATION DATE:  06/22/2020
Name:       REDWOOD CITY, WHARF 5, S. F. BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 30.4' N (  37.50670)
USGS Quad:  REDWOOD POINT                   Longitude: 122° 12.6' W (-122.21000)


                             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.

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