U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9415205 PUBLICATION DATE: 02/26/2004
Name: MONTEZUMA SLOUGH, SUISUN BAY
CA
NOAA Chart: 18656 Latitude: 38° 4.6' N ( 38.07670)
USGS Quad: HONKER BAY Longitude: 121° 53.1' W (-121.88500)
To reach the tidal bench marks from Pittsburg, proceed by boat in a NE direction
in Suisun Bay to the entrance to Montezuma Slough bordering the NE side of Van
Sickle Island, and then proceed to beyond first bend in the slough. The bench
marks are on Van Sickle Island. The tide gage and staff were located on a
wooden pier on the slough behind a building near the slough.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 5205 B 1977
DESIGNATION: 941 5205 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 8603
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 38° 5.3' N ( 38.08830) LONGITUDE: 121° 53.0' W (-121.88300)
The primary bench mark is a disk located north from three stacks at Pittsburg
and ESE of bench mark 5205 C 1977, 15.24 m (50.0 ft) SSW from the centerline of
the levee road, and 0.91 m (3.0 ft) south from a power pole. The bench mark is
crimped to the top of a copper-clad steel rod driven 19.5 m (64.0 ft) to refusal
and encased in a PVC pipe extending 9 cm (0.3 ft) above the grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9415205 PUBLICATION DATE: 02/26/2004
Name: MONTEZUMA SLOUGH, SUISUN BAY
CA
NOAA Chart: 18656 Latitude: 38° 4.6' N ( 38.07670)
USGS Quad: HONKER BAY Longitude: 121° 53.1' W (-121.88500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5205 D 1977
DESIGNATION: 941 5205 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 8605
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 38° 5.3' N ( 38.08830) LONGITUDE: 121° 53.0' W (-121.88300)
The bench mark is a disk located north from three stacks in Pittsburg and WSW
from mollasses tanks at MacDougall Feed Company, 125 m (410 ft) west of bench
mark 5205 C 1977, 15 m (49 ft) WNW from underground natural gas pipeline with
warning signs nearby, 3.66 m (12.0 ft) ENE from the centerline of the gravel
road, and 0.61 m (2.0 ft) north of a power pole. The bench mark is crimped to
the top of a copper-clad steel rod driven 19.5 m (64.0 ft) to refusal and
encased in a PVC pipe extending 9 cm (0.3 ft) above the grade.
BENCH MARK STAMPING: 5205 F 1990
DESIGNATION: 941 5205 F TIDAL
MONUMENTATION: Tidal Station disk VM#: 8607
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 38° 5.3' N ( 38.08830) LONGITUDE: 121° 53.0' W (-121.88300)
The bench mark is a disk set in a concrete monument 59 m (194 ft) SE along the
SW levee road of Montezuma Slough from a wood pier and the station, 8.81 m (28.9
ft) SW of the center of the levee road, 2.99 m (9.8 ft) NE of the extension of
the NE face of a 2-story wood hunting lodge, 10.00 m (32.8 ft) south of the
Y-Junction of the levee road and a gravel driveway, 1.49 m (4.9 ft) below the
levee road, and 0.80 m (2.6 ft) NW of a metal witness post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9415205 PUBLICATION DATE: 02/26/2004
Name: MONTEZUMA SLOUGH, SUISUN BAY
CA
NOAA Chart: 18656 Latitude: 38° 4.6' N ( 38.07670)
USGS Quad: HONKER BAY Longitude: 121° 53.1' W (-121.88500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5205 H 1990
DESIGNATION: 941 5205 H TIDAL
MONUMENTATION: Tidal Station disk VM#: 8609
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 38° 5.3' N ( 38.08830) LONGITUDE: 121° 53.0' W (-121.88300)
The bench mark is a disk set in a concrete monument 0.3 km (0.2 mi) NW along the
SW levee road of Montezuma Slough from the wood hunting lodge, 29 m (96 ft) NW
of a pipe gate, 12.71 (41.7 ft) NE of the road center, 1.01 m (3.3 ft) NE of a
119 m (3.9 ft) metal speed control sign for boaters, and 0.21 m (0.7 ft) below
ground.
BENCH MARK STAMPING: S71 (CADWR)
DESIGNATION: 941 5205 S71 (CADWR)
MONUMENTATION: Survey disk VM#: 8610
AGENCY: California Department of Water Resources
(CADWR) IDB PID#:
SETTING CLASSIFICATION: Rod mark OPUS PID#: BBCQ23
LATITUDE: 38° 5.3' N ( 38.08830) LONGITUDE: 121° 53.0' W (-121.88300)
The bench mark is 53 m (175 ft) NW along the west levee road of Montezuma Slough
from the west end of the California DWR Flood Control Gates, 6.89 m (22.6 ft) SW
of the center of the levee road, 3.29 m (10.8 ft) SE of the SE-most one of 8
metal floor gates to the roaring river slough, and 0.70 m (2.3 ft) west of a
0.46 m (1.5 ft) tall metal guard rail. The bench mark is a rod mark, encased in
a 6-inch gray plastic SCH 40 pipe which projects 15 cm (0.5 ft) above the
ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9415205 PUBLICATION DATE: 02/26/2004
Name: MONTEZUMA SLOUGH, SUISUN BAY
CA
NOAA Chart: 18656 Latitude: 38° 4.6' N ( 38.07670)
USGS Quad: HONKER BAY Longitude: 121° 53.1' W (-121.88500)
T I D A L D A T U M S
Tidal datums at MONTEZUMA SLOUGH, SUISUN BAY based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: November 1990 - December 1990
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 = 1.323
MEAN HIGH WATER MHW = 1.178
MEAN SEA LEVEL MSL = 0.702
MEAN TIDE LEVEL MTL = 0.689
MEAN LOW WATER MLW = 0.200
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
5205 B 1977 0.595 -0.583
5205 D 1977 1.219 0.041
5205 F 1990 1.374 0.196
5205 H 1990 2.217 1.039
S71 (CADWR) 2.095 0.917
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9415205 PUBLICATION DATE: 02/26/2004
Name: MONTEZUMA SLOUGH, SUISUN BAY
CA
NOAA Chart: 18656 Latitude: 38° 4.6' N ( 38.07670)
USGS Quad: HONKER BAY Longitude: 121° 53.1' W (-121.88500)
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.