U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9415053 PUBLICATION DATE: 03/10/2011
Name: DUTCH SLOUGH
CA
NOAA Chart: 18661 Latitude: 38° 0.7' N ( 38.01170)
USGS Quad: JERSEY ISLAND Longitude: 121° 38.3' W (-121.63800)
To reach the tidal bench marks from Highway 4 take the Bethel Island exit onto
East Cypress Road and proceed east for 5 km (3 mi), then turn left and proceed
north on Bethel Island Road for 3 km (2 mi) to the north end of Bethel Island
Bridge, then turn right and proceed east on Riverview Drive for 91 m (300 ft) to
the Farrar Park Marina property. The bench marks are located along the Dutch
Slough Road, west of the Bethel Island Road Bridge. The tide gage and staff
were located on the stairway beyond the Farrar Park Marina office.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 5053 B 1978
DESIGNATION: 941 5053 B
MONUMENTATION: Tidal Station disk VM#: 8507
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 38° 0.7' N ( 38.01170) LONGITUDE: 121° 38.3' W (-121.63800)
The primary bench mark is a disk located along Dutch Slough Road, 51 m (168 ft)
west of bench mark 69 MDC 1974, 3.66 m (12.0 ft) north from centerline of Dutch
Slough Road, and 0.76 m (2.5 ft) north from witness post. The bench mark is set
0.03 m (0.1 ft) below grade, crimped to the top of a galvanized steel rod driven
13.7 m (45 ft) to refusal, encased in a 4-inch PVC pipe and kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9415053 PUBLICATION DATE: 03/10/2011
Name: DUTCH SLOUGH
CA
NOAA Chart: 18661 Latitude: 38° 0.7' N ( 38.01170)
USGS Quad: JERSEY ISLAND Longitude: 121° 38.3' W (-121.63800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5053 A RESET 1979
DESIGNATION: 941 5053 A RESET
MONUMENTATION: Tidal Station disk VM#: 8506
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Sidewalk OPUS PID:
LATITUDE: 38° 0.7' N ( 38.01170) LONGITUDE: 121° 38.3' W (-121.63800)
The bench mark is a disk set in the corner of the sidewalk at the NW end of the
Bethel Island Road bridge over Dutch Slough, 32 m (104 ft) SSW from the center
of the intersection of Bethel Island and Riverview Roads, 21 m (68 ft) WNW of
the NE corner of the Bethel Island Yacht Sales office, and 4 m (14 ft) west of
centerline of Bethel Island Road.
BENCH MARK STAMPING: 69 MDC 1974 ELEV 10 FT
DESIGNATION: 69 MDC
MONUMENTATION: Tidal Station disk VM#: 8510
AGENCY: US Geological Survey (USGS) IDB PID#:
SETTING CLASSIFICATION: Abutment OPUS PID:
LATITUDE: 38° 0.7' N ( 38.01170) LONGITUDE: 121° 38.3' W (-121.63800)
The bench mark is a disk set on an abutment at the SW end of the Bethel Island
Road Bridge over the Slough, 14.63 m (48.0 ft) NNE from the NE corner of Keller
Liquor Store, 6.25 m (20.5 ft) east from center of Bethel Island Road, 5 m (17
ft) north from the center of Dutch Slough Road, and 0.91 m (3.0 ft) below road
level of bridge.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9415053 PUBLICATION DATE: 03/10/2011
Name: DUTCH SLOUGH
CA
NOAA Chart: 18661 Latitude: 38° 0.7' N ( 38.01170)
USGS Quad: JERSEY ISLAND Longitude: 121° 38.3' W (-121.63800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5053 E 1991
DESIGNATION: 941 5053 E
MONUMENTATION: Tidal Station disk VM#: 8513
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Asphalt parking lot OPUS PID#: BBDV90
LATITUDE: 38° 0.7' N ( 38.01170) LONGITUDE: 121° 38.3' W (-121.63800)
The bench mark is a disk set flush into the concrete which edges the
asphalt-paved parking lot on the north side of the Summit Marina showroom, 3.41
m (11.2 ft) SSW of the most SW of four yellow I-beam posts which surround a
propane tank (I-beam post stands approximately 0.91 m (3.0 ft) above pavement),
2.75 m (9.0 ft) north of the NE corner of the Summit Marina showroom building,
and 1.28 m (4.2 ft) east of a wood-clad 0.09 m x 0.15 m (0.3 ft x 0.5 ft)
stanchion which supports the roof overhang of the Summit Marina building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9415053 PUBLICATION DATE: 03/10/2011
Name: DUTCH SLOUGH
CA
NOAA Chart: 18661 Latitude: 38° 0.7' N ( 38.01170)
USGS Quad: JERSEY ISLAND Longitude: 121° 38.3' W (-121.63800)
T I D A L D A T U M S
Tidal datums at DUTCH SLOUGH based on:
LENGTH OF SERIES: 5 MONTHS
TIME PERIOD: November 1991 - March 1992
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 = 1.050
MEAN HIGH WATER MHW = 0.911
MEAN SEA LEVEL MSL = 0.539
MEAN TIDE LEVEL MTL = 0.536
MEAN LOW WATER MLW = 0.160
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
5053 B 1978 2.155 1.244
5053 A RESET 1979 3.048 2.137
69 MDC 1974 ELEV 10 FT 3.222 2.311
5053 E 1991 2.866 1.955
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9415053 PUBLICATION DATE: 03/10/2011
Name: DUTCH SLOUGH
CA
NOAA Chart: 18661 Latitude: 38° 0.7' N ( 38.01170)
USGS Quad: JERSEY ISLAND Longitude: 121° 38.3' W (-121.63800)
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.