U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
Station ID: 9415252 PUBLICATION DATE: 09/21/2016
Name: PETALUMA RIVER ENTRANCE
CA
NOAA Chart: 18654 Latitude: 38° 6.9' N ( 38.11531)
USGS Quad: PETALUMA RIVER Longitude: 122° 30.3' W (-122.50567)
To reach the tidal bench marks from the Black Point post office and general
store, proceed NE along Harbor Drive for 0.5 km (0.3 mi) to the intersection of
Harbor Drive and Grandview Avenue. The bench marks are in the vicinity of the
tide station and Harbor Drive. The tide gage and staff were located on the
north side of the northwestern Pacific Railroad swingbridge at Black Point.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 5252 E 1977
DESIGNATION: 941 5252 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 8627
AGENCY: National Ocean Survey (NOS) IDB PID#: JT9547
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID#: JT9547
LATITUDE: 38° 6.6' N ( 38.11069) LONGITUDE: 122° 30.2' W (-122.50339)
The bench mark is a disk along the the SW end of a parking lot located west of
the end of Beattie Lane, 29 m (95 ft) south of the railroad signal box, 21.1 m
(69 ft) SE of the SE rail of the existing railroad, 12.6 m (41.3 ft) SW of a
fire hydrant, and 2.5 m (8.2 ft) SW of power pole #178562/110533731 . The bench
mark is crimped to the top of a copper-clad steel rod driven 23.5 m (77 ft) to
refusal, and encased in a PVC pipe extending 0.12 m (0.4 ft) above grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 9415252 PUBLICATION DATE: 09/21/2016
Name: PETALUMA RIVER ENTRANCE
CA
NOAA Chart: 18654 Latitude: 38° 6.9' N ( 38.11531)
USGS Quad: PETALUMA RIVER Longitude: 122° 30.3' W (-122.50567)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 13 1951
DESIGNATION: 941 5252 TIDAL 13
MONUMENTATION: Tidal Station disk VM#: 8626
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: JT0903
SETTING CLASSIFICATION: Concrete head wall OPUS PID:
LATITUDE: 38° 6.5' N ( 38.10830) LONGITUDE: 122° 30.4' W (-122.50700)
The bench mark is a disk set in the top of the SE end of the SE concrete head
wall of a pipe culvert under Harbor Drive, 0.5 km (0.3 mi) SW of the
Northwestern Pacific Railroad bridge over the creek, 87 m (285 ft) NE of the
intersection of Harbor Drive and Grandview Avenue, 50 m (164 ft) NW of the Black
Point Post Office and general store, 27 m (87 ft) NW of the Northwestern Pacific
Railroad tracks, 5.03 m (16.5 ft) south of the centerline of Harbor Drive and
0.46 m (1.5 ft) below highway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 9415252 PUBLICATION DATE: 09/21/2016
Name: PETALUMA RIVER ENTRANCE
CA
NOAA Chart: 18654 Latitude: 38° 6.9' N ( 38.11531)
USGS Quad: PETALUMA RIVER Longitude: 122° 30.3' W (-122.50567)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 941 5252 TIDAL 8
ALIAS: 8 1921, NO STAMPING 1
MONUMENTATION: Tidal Station disk VM#: 8628
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: JT0907
SETTING CLASSIFICATION: Concrete pier OPUS PID:
LATITUDE: 38° 6.7' N ( 38.11170) LONGITUDE: 122° 30.1' W (-122.50200)
The primary bench mark is the top of the SE end of the NE concrete pier of the
drawbridge over the creek, 0.5 km (0.3 mi) NE along Northwestern Pacific
Railroad from the post office and general store at Black Point, 3 m (9 ft) SE of
the SE rail, and 2 m (6 ft) below track level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 9415252 PUBLICATION DATE: 09/21/2016
Name: PETALUMA RIVER ENTRANCE
CA
NOAA Chart: 18654 Latitude: 38° 6.9' N ( 38.11531)
USGS Quad: PETALUMA RIVER Longitude: 122° 30.3' W (-122.50567)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 941 5252 TIDAL 9
ALIAS: 9 1921, NO STAMPING 2
MONUMENTATION: Tidal Station disk VM#: 8629
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: JT0906
SETTING CLASSIFICATION: Concrete pier OPUS PID:
LATITUDE: 38° 6.7' N ( 38.11189) LONGITUDE: 122° 30.1' W (-122.50219)
The bench mark is located 142 m (466 ft) NE of the nearest semaphore, 67.40 m
(221.1 ft) north of the closest northerly house, 40.20 m (131.9 ft) NE of the
corner of a shed, and 1.44 m (4.72 ft) SE of the east rail. The bench mark is a
disk set on top of a concrete abutment pier, approximately 1.80 m (5.9 ft) below
the tracks.
BENCH MARK STAMPING: MARIN COUNTY BM BP 1
DESIGNATION: 941 5252 MARIN COUNTY
MONUMENTATION: Bench Mark disk VM#: 8630
AGENCY: Marin County Public Works Department IDB PID#:
SETTING CLASSIFICATION: Concrete head wall of culvert OPUS PID:
LATITUDE: 38° 6.6' N ( 38.10928) LONGITUDE: 122° 30.4' W (-122.50617)
The bench mark is located approximately 32.67 m (107.2 ft) NW of the SW railroad
signal arm, 23.96 m (78.6 ft) WSW of power pole #3636A, 20.46 m (67.1 ft) SW of
a fire hydrant. The bench mark is a 2 in. brass disk mounted on a concrete
culvert headwall on the NW side of the street, at pavement grade, near the SW
edge of the driveway for 55 Harbor Dr.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 9415252 PUBLICATION DATE: 09/21/2016
Name: PETALUMA RIVER ENTRANCE
CA
NOAA Chart: 18654 Latitude: 38° 6.9' N ( 38.11531)
USGS Quad: PETALUMA RIVER Longitude: 122° 30.3' W (-122.50567)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5252 F 2014
DESIGNATION: 9415252 F TIDAL
MONUMENTATION: Bench Mark disk VM#: 22027
AGENCY: U.S. Army Corps of Engineers (USACE) IDB PID#:
SETTING CLASSIFICATION: Concrete footer - bridge OPUS PID:
LATITUDE: 38° 6.9' N ( 38.11536) LONGITUDE: 122° 30.3' W (-122.50558)
The bench mark is located 8.3 m (27.2 ft) NW of a bridge column, 1.88 m (6.17
ft) SE of another bridge column, 1.6 m (5.2 ft) west of the east edge of a
concrete bridge footing structure. This benchmark is a brass disk set on top of
the concrete bridge footing structure on the NE side of the Petaluma River boat
channel, and it requires a boat to access.
BENCH MARK STAMPING: 5252 G 2014
DESIGNATION: 9415252 G TIDAL
MONUMENTATION: Bench Mark disk VM#: 22028
AGENCY: U.S. Army Corps of Engineers (USACE) IDB PID#:
SETTING CLASSIFICATION: Concrete walkway OPUS PID#: BBDJ92
LATITUDE: 38° 6.9' N ( 38.11455) LONGITUDE: 122° 30.4' W (-122.50633)
The bench mark is located 40.18 m (131.8 ft) NE of the NE corner of the public
restroom building, 22.86 m (75 ft) ENE of the south end of the Black Point Boat
Launch sign, and 12.21 m (40.1 ft) north of a 0.6 m (2 ft) square storm inlet.
The bench mark is a brass disk set on top of the concrete walkway structure on
the north side of the boat ramp at the most northern corner of the walkway
structure, approximately 1.0 m (3.3 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 9415252 PUBLICATION DATE: 09/21/2016
Name: PETALUMA RIVER ENTRANCE
CA
NOAA Chart: 18654 Latitude: 38° 6.9' N ( 38.11531)
USGS Quad: PETALUMA RIVER Longitude: 122° 30.3' W (-122.50567)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5252 H 2014
DESIGNATION: 9415252 H TIDAL
MONUMENTATION: Bench Mark disk VM#: 22029
AGENCY: U.S. Army Corps of Engineers (USACE) IDB PID#:
SETTING CLASSIFICATION: Concrete drainage culvert OPUS PID:
LATITUDE: 38° 6.7' N ( 38.11192) LONGITUDE: 122° 30.5' W (-122.50875)
The bench mark is located 53.44 m (175.3 ft) NE of the NE corner of the house at
300 Harbor Dr., 50.37 m (165.3 ft) north of power pole #026033 #CT 39423, and
44.62 m (146.4 ft) SE of a fire hydrant on Crest Rd. This bench mark is a brass
disk set on top of the concrete headwall for a drainage culvert, approximately
1.0 m (3.3 ft) above ground on the west side of wall and 0.4 m (1.3 ft) above
ground on the east side.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 9415252 PUBLICATION DATE: 09/21/2016
Name: PETALUMA RIVER ENTRANCE
CA
NOAA Chart: 18654 Latitude: 38° 6.9' N ( 38.11531)
USGS Quad: PETALUMA RIVER Longitude: 122° 30.3' W (-122.50567)
T I D A L D A T U M S
Tidal datums at PETALUMA RIVER ENTRANCE based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: April 2014 - June 2014
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9414290 SAN FRANCISCO, SAN FRANCISCO BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.832
MEAN HIGH WATER MHW = 1.668
MEAN SEA LEVEL MSL = 0.984
MEAN TIDE LEVEL MTL = 0.977
MEAN LOW WATER MLW = 0.286
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum NAVD88 = -0.089
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
5252 E 1977 1.681 0.013
NO 13 1951 2.258 0.590
941 5252 TIDAL 8 2.602 0.934
941 5252 TIDAL 9 2.653 0.985
MARIN COUNTY BM BP 1 2.674 1.006
5252 F 2014 3.482 1.814
5252 G 2014 2.929 1.261
5252 H 2014 14.048 12.380
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 9415252 PUBLICATION DATE: 09/21/2016
Name: PETALUMA RIVER ENTRANCE
CA
NOAA Chart: 18654 Latitude: 38° 6.9' N ( 38.11531)
USGS Quad: PETALUMA RIVER Longitude: 122° 30.3' W (-122.50567)
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.