U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 9415338 PUBLICATION DATE: 06/05/2013
Name: SONOMA CK.ENTR.,SAN PABLO BAY
CA
NOAA Chart: Latitude: 38° 9.4' N ( 38.15670)
USGS Quad: Longitude: 122° 24.4' W (-122.40700)
To reach the tidal bench marks proceed 3.4 km (2.1 mi) east along State Highway
37 from intersection of State Highway 121 at Sears Point thence over the Sonoma
Creek Highway Bridge to the west bank of the creek. The bench marks are in the
vicinity. The tide gage and staff were located on the bridge fender under the
navigation span.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: UNSTAMPED
DESIGNATION: 941 5338 TIDAL 3
ALIAS: 3 1931
MONUMENTATION: Survey disk VM#: 11935
AGENCY: CO-OPS IDB PID#: JT0283
SETTING CLASSIFICATION: Transmission tower foundation OPUS PID:
LATITUDE: 38° 9.3' N ( 38.15550) LONGITUDE: 122° 24.5' W (-122.40914)
THE PRIMARY BENCH MARK IS A DISK SET IN THE NORTHEAST 0.93 M (3.1 FT) X 0.93 M
(3.1 FT) CONCRETE FOOTING FOR A P.G. AND E. ELECTRICAL TOWER, 43.60 M (143.0 FT)
EAST-NORTHEAST OF BENCH MARK 941 5338 G, 24.92 M (81.8 FT) SOUTH OF THE SOUTHERN
EDGE OF THE HIGHWAY 37 BRIDGE, 6.00 M (19.7 FT) EAST-NORTHEAST OF THE NORTHWEST
LEG OF THE TOWER, 0.41 M (1.3 FT) NORTH-NORTHEAST OF THE NORTHEAST LEG OF THE
TOWER, 0.28 M (0.9 FT) SOUTH-SOUTHWEST OF THE NORTHEAST CORNER OF THE CONCRETE
AND 0.35 M (1.1 FT) ABOVE THE GROUND.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9415338 PUBLICATION DATE: 06/05/2013
Name: SONOMA CK.ENTR.,SAN PABLO BAY
CA
NOAA Chart: Latitude: 38° 9.4' N ( 38.15670)
USGS Quad: Longitude: 122° 24.4' W (-122.40700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5338 G 2012
DESIGNATION: 941 5338 G
MONUMENTATION: Bench Mark disk VM#: 20608
AGENCY: CO-OPS IDB PID#:
SETTING CLASSIFICATION: Base of viewing platform OPUS PID#: BBCW75
LATITUDE: 38° 9.3' N ( 38.15539) LONGITUDE: 122° 24.6' W (-122.40958)
THE BENCH MARK IS A DISK SET IN A 0.3 M (1.0 FT) THICK CONCRETE SLAB FOR THE
WILDLIFE VIEWING PLATFORM, 43.60 M (143.0 FT) WEST-SOUTHWEST OF BENCH MARK 941
5338 TIDAL 3, 13.67 M (44.8 FT) NORTH-NORTHEAST OF A POWER POLE, 0.65 M (2.1 FT)
SOUTH OF THE SOUTHERN EDGE OF THE PATH, 0.59 M (1.9 FT) WEST-NORTHWEST OF A
WITNESS SIGN AND THE WOODEN BASE OF THE PLATFORM, 0.57 M (1.9 FT) NORTHEAST OF
THE WOODEN BASE OF THE PLATFORM AND 0.35 M (1.1 FT) SOUTH OF THE EDGE OF THE
CONCRETE SLAB.
BENCH MARK STAMPING: 5338 H 2012
DESIGNATION: 941 5338 H
MONUMENTATION: Bench Mark disk VM#: 20609
AGENCY: CO-OPS IDB PID#:
SETTING CLASSIFICATION: Transmission tower footing OPUS PID:
LATITUDE: 38° 9.4' N ( 38.15661) LONGITUDE: 122° 24.6' W (-122.40958)
THE BENCH MARK IS A DISK SET IN THE NORTHEAST CONCRETE FOOTER OF AN ELECTRICAL
TOWER, 44.20 M (145.0 FT) NORTHWEST OF A DERELICT METAL SHACK, 12.05 M (39.5 FT)
WEST OF THE TOP OF THE LEVEE, 11.98 M (39.3 FT) EAST OF THE NORTHWEST LEG OF THE
TOWER, AND 0.65 M (2.1 FT) ABOVE GROUND.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9415338 PUBLICATION DATE: 06/05/2013
Name: SONOMA CK.ENTR.,SAN PABLO BAY
CA
NOAA Chart: Latitude: 38° 9.4' N ( 38.15670)
USGS Quad: Longitude: 122° 24.4' W (-122.40700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: EE 552 1956
DESIGNATION: EE 552
MONUMENTATION: Bench Mark disk VM#: 20610
AGENCY: IDB PID#: JT0282
SETTING CLASSIFICATION: Tower foundation OPUS PID:
LATITUDE: 38° 9.4' N ( 38.15589) LONGITUDE: 122° 24.8' W (-122.41408)
THE BENCH MARK IS A DISK SET IN THE SOUTHWEST CONCRETE FOUNDATION FOR AN
ELECTRICAL TRANSMISSION TOWER, 72.70 M (238.5 FT) WEST-SOUTHWEST OF THE
SOUTHWEST LEG OF AN ADJACENT TOWER WITH A SEPARATE POWER LINE, 17.33 M (56.9 FT)
WEST-NORTHWEST OF A WOODEN TELEPHONE POLE, 12.0 M (39.4 FT) NORTH OF THE NORTH
SIDE OF A DRAINAGE DITCH, 6.34 M (20.8 FT) WEST-NORTHWEST OF THE SOUTHEAST LEG
OF THE SAME TOWER AND 1.25 M (4.1 FT) ABOVE THE GROUND.
BENCH MARK STAMPING: TIDAL 3 RESET
DESIGNATION: 941 5338 TIDAL 3 RESET
MONUMENTATION: Tidal Station disk VM#: 20611
AGENCY: CGS IDB PID#: JT0279
SETTING CLASSIFICATION: Tower foundation OPUS PID:
LATITUDE: 38° 9.4' N ( 38.15658) LONGITUDE: 122° 25.3' W (-122.42222)
THE BENCH MARK IS A DISK SET IN THE NORTHEAST CONCRETE FOOTING OF AN ELECTRIC
LINE TOWER, 156.9 M (514.8 FT) NORTH-NORTHWEST OF THE CENTERLINE OF THE GATE AT
THE ENTRANCE TO THE DRIVEWAY OFF OF HIGHWAY 37, 50.80 M (166.7 FT)
WEST-NORTHWEST FROM THE CENTERLINE OF A DIRT ROAD, 15.77 M (51.7 FT) SOUTH OF
THE SOUTHEAST LEG OF AN ADJACENT TOWER WITH SEPARATE POWER LINES, 4.94 M (16.2
FT) EAST-NORTHEAST OF THE NORTHWEST LEG OF THE TOWER ON WHICH THE BENCH MARK IS
SET AND 1.43 M (4.7 FT) ABOVE THE GROUND.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9415338 PUBLICATION DATE: 06/05/2013
Name: SONOMA CK.ENTR.,SAN PABLO BAY
CA
NOAA Chart: Latitude: 38° 9.4' N ( 38.15670)
USGS Quad: Longitude: 122° 24.4' W (-122.40700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 941 5338 MWWL
MONUMENTATION: See descriptive text VM#: 20612
AGENCY: IDB PID#:
SETTING CLASSIFICATION: MWWL Sensor OPUS PID:
LATITUDE: 38° 9.3' N ( 38.15569) LONGITUDE: 122° 24.4' W (-122.40725)
MWWL SENSOR UNDERNEATH HIGHWAY 37 BRIDGE AT SONOMA CREEK
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9415338 PUBLICATION DATE: 06/05/2013
Name: SONOMA CK.ENTR.,SAN PABLO BAY
CA
NOAA Chart: Latitude: 38° 9.4' N ( 38.15670)
USGS Quad: Longitude: 122° 24.4' W (-122.40700)
T I D A L D A T U M S
Tidal datums at SONOMA CK.ENTR.,SAN PABLO BAY based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: November 2012 - February 2013
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9415144 PORT CHICAGO, SUISUN BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.655
MEAN HIGH WATER MHW = 1.475
MEAN TIDE LEVEL MTL = 0.839
MEAN SEA LEVEL MSL = 0.826
MEAN LOW WATER MLW = 0.203
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum NAVD88 = -0.303
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
UNSTAMPED 2.162 0.687
5338 G 2012 2.766 1.291
5338 H 2012 1.711 0.236
EE 552 1956 1.291 -0.184
TIDAL 3 RESET 1.319 -0.156
941 5338 MWWL 4.825 3.350
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9415338 PUBLICATION DATE: 06/05/2013
Name: SONOMA CK.ENTR.,SAN PABLO BAY
CA
NOAA Chart: Latitude: 38° 9.4' N ( 38.15670)
USGS Quad: Longitude: 122° 24.4' W (-122.40700)
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.