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Bench Mark Sheet for 9414632, ALAMEDA CREEK, SAN FRANCISCO BAY 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  5

                                                                                
Station ID: 9414632                         PUBLICATION DATE:  01/24/2018
Name:       ALAMEDA CREEK, SAN FRANCISCO BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 35.7' N (  37.59500)
USGS Quad:  REDWOOD POINT                   Longitude: 122°  8.7' W (-122.14500)


To reach the tidal bench marks from State Road 17 and the Alvarado-Niles
Boulevard exit, proceed west on Alvarado-Niles Boulevard for 1.8 km (1.1 mi) to
Union City Boulevard, turn left onto Union City Boulevard and take the second
right, then 1.21 km (0.75 mi) to a T junction, turn left and go 0.1 mile (0.2
km) to a one lane road on the right (between an auto junkyard and sewage plant),
go through the gate to the sewage plant and then to the T junction at end of the
narrow road, turn right and then go behind the pump house, turn left and go up
onto the top of the levee, then left on the levee road for 5.6 km (3.5 mi) to
the end of the road.  The bench marks are on the south side of the creek. The
tide gage and staff were on a small platform about 0.40 km (0.25 mi) east of the
entrance to the creek.


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


                 PRIMARY BENCH MARK STAMPING:  4632 A 1976
                         DESIGNATION:          941 4632 A

MONUMENTATION:           Tidal Station disk                    VM#:         8372
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  HT2362
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   37° 35.7' N (  37.59500)          LONGITUDE: 122°  8.7' W (-122.14500)


The primary bench mark is a disk located on the southern levee road along the
creek, about 122 m (400 ft) east of the end of the levee road, 16.61 m (54.5 ft)
north of the south edge of the levee, 7 m (24 ft) south of the vegetation, and
0.55 m (1.8 ft) south of a witness post. The bench mark is crimped to the top of
a copper-clad steel rod driven 17.1 m (56 ft) to refusal.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 9414632                         PUBLICATION DATE:  01/24/2018
Name:       ALAMEDA CREEK, SAN FRANCISCO BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 35.7' N (  37.59500)
USGS Quad:  REDWOOD POINT                   Longitude: 122°  8.7' W (-122.14500)


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


                         BENCH MARK STAMPING:  4632 B 1976
                         DESIGNATION:          941 4632 B

MONUMENTATION:           Tidal Station disk                    VM#:         8373
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  HT2361
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   37° 35.7' N (  37.59500)          LONGITUDE: 122°  8.7' W (-122.14500)


The bench mark is a disk located 110 m (360 ft) east of bench mark 4632 A 1976,
16 m (54 ft) north of the south side of the levee, 12 m (38 ft) south of the
vegetation on the south bank of the creek, 1.19 m (3.9 ft) SSE of a witness
post, and 0.15 m (0.5 ft) above the ground. The bench mark is crimped to the top
of a copper-clad steel rod driven 14.6 m (48 ft) to refusal and encased in a PVC
pipe.



                         BENCH MARK STAMPING:  4632 C 1976
                         DESIGNATION:          941 4632 C

MONUMENTATION:           Tidal Station disk                    VM#:         8374
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  HT2360
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   37° 35.7' N (  37.59500)          LONGITUDE: 122°  8.7' W (-122.14500)


The bench mark is a disk located on the levee road along the south side of the
creek, 119 m (390 ft) east of bench mark 4632 B 1976, about 20 m (65 ft) south
of the centerline of the creek, 7 m (23 ft) north of the centerline of the road,
and 1 m (4 ft) south of a witness post. The bench mark is set 0.15 m (0.5 ft)
above ground crimped to the top of a copper-clad steel rod driven 17.1 m (56 ft)
to refusal, and encased in a PVC pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 9414632                         PUBLICATION DATE:  01/24/2018
Name:       ALAMEDA CREEK, SAN FRANCISCO BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 35.7' N (  37.59500)
USGS Quad:  REDWOOD POINT                   Longitude: 122°  8.7' W (-122.14500)


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


                         BENCH MARK STAMPING:  4632 D 1976
                         DESIGNATION:          941 4632 D

MONUMENTATION:           Tidal Station disk                    VM#:         8375
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  HT2358
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   37° 35.7' N (  37.59500)          LONGITUDE: 122°  8.7' W (-122.14500)


The bench mark is a disk located 84 m (275 ft) ESE of bench mark 4632 C 1976,
about 23 m (75 ft) south of the centerline of the creek, and 1.07 m (3.5 ft) SSW
of a witness post. The bench mark is set 0.15 m (0.5 ft) above ground, crimped
to the top of a copper-clad steel rod driven 24.4 m (80 ft) to refusal and
encased in a 4 inch PVC pipe.



                         BENCH MARK STAMPING:  4632 E 1976
                         DESIGNATION:          941 4632 E

MONUMENTATION:           Tidal Station disk                    VM#:         8376
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  HT2357
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   37° 35.7' N (  37.59500)          LONGITUDE: 122°  8.7' W (-122.14500)


The bench mark is a disk located on the north side of the levee at a T-junction
of the levee road on the south side of the creek, near a levee road heading
south, 134 m (440 ft) ESE of bench mark 4632 D 1976, 36 m (119 ft) NNE of two
wooden gate posts, about 30 m (100 ft) SSW of the centerline of the creek, and
1.37 m (4.5 ft) south of a witness post. The bench mark is crimped to the top of
a copper-clad steel rod driven 15.3 m (50 ft) to refusal.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 9414632                         PUBLICATION DATE:  01/24/2018
Name:       ALAMEDA CREEK, SAN FRANCISCO BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 35.7' N (  37.59500)
USGS Quad:  REDWOOD POINT                   Longitude: 122°  8.7' W (-122.14500)


                            T I D A L   D A T U M S 


Tidal datums at ALAMEDA CREEK, SAN FRANCISCO BAY based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           December 1976 - February 1977
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9414458 SAN MATEO BRIDGE, WEST SIDE


Elevations of tidal datums referred to Mean High Water (MHW), in METERS:

     MEAN HIGHER HIGH WATER                     MHHW   =  0.190
     MEAN HIGH WATER                            MHW    =  0.000
     North American Vertical Datum              NAVD88 = -1.947

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                                MHW

     4632 A 1976                                          1.265
     4632 B 1976                                          1.210
     4632 C 1976                                          0.874
     4632 D 1976                                          1.960
     4632 E 1976                                          0.824


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

                                                                                
Station ID: 9414632                         PUBLICATION DATE:  01/24/2018
Name:       ALAMEDA CREEK, SAN FRANCISCO BAY                  
            CA
NOAA Chart: 18651                           Latitude:   37° 35.7' N (  37.59500)
USGS Quad:  REDWOOD POINT                   Longitude: 122°  8.7' W (-122.14500)


                             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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Products available at 9414632 ALAMEDA CREEK, SAN FRANCISCO BAY, CA

Revised: 10/15/2013
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services