U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 05/03/1983
Station ID: 9413624 SUPERCEDED DATE: 04/21/2003
Name: ELKHORN SLOUGH, PACIFICMARICULTURE DOCK
CALIFORNIA
NOAA Chart: 18680 Latitude: 36° 38.8' N
USGS Quad: MOSSLANDING Longitude: 121° 45.5' W
To reach the tidal bench marks proceed east along levee road on south bank of
Elkhorn from State Highway 1 in Moss Landing to the Pacific Mariculture yard and
dock. The tide gage and staff were located on the SE corner of the east
extension of the pier in the slough.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 3624 A 1977
MONUMENTATION: Survey Disk VM#: 8063
AGENCY: PID:
SETTING CLASSIFICATION: Copper-Clad Steel Rod
The bench mark is NE of Pacific Gas and Electric stacks at Moss Landing, 140
feet (42.7 m) SE of Elkhorn Slough, 8 feet (2.4 m) west of the centerline of
road leading to Pacific Mariculture yard and dock, 3 feet (0.9 m) SSE of a
wooden witness post, 1 foot (0.3 m) north of a steel witness post, and 0.2 foot
(0.06 m) above the grade. The bench mark is on a rod driven 80 feet (24.4 m)
and inside a PVC pipe.
BENCH MARK STAMPING: 3624 B 1977
MONUMENTATION: Survey Disk VM#: 8064
AGENCY: PID:
SETTING CLASSIFICATION: Steel Rod
The bench mark is NE of Pacific Gas and Electric stacks at Moss Landing, 389.5
feet (118.7 m) west along levee road from Bench Mark 3624 C 1977, 332.5 feet
(101.3 m) east of Bench Mark 3624 A 1977, 250 feet (76.2 m) south of the slough,
9.0 feet (2.7 m) north of the centerline of the levee road, and flush with the
grade. The bench mark is on a rod driven to 64 feet (19.5 m) and inside a PVC
pipe.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 05/03/1983
Station ID: 9413624 SUPERCEDED DATE: 04/21/2003
Name: ELKHORN SLOUGH, PACIFICMARICULTURE DOCK
CALIFORNIA
NOAA Chart: 18680 Latitude: 36° 38.8' N
USGS Quad: MOSSLANDING Longitude: 121° 45.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3624 C 1977
MONUMENTATION: Survey Disk VM#: 8065
AGENCY: PID:
SETTING CLASSIFICATION: Copper-Clad Steel Rod
The bench mark is NE from the Pacific Gas and Electric power plant stacks, 389.6
feet (118.7 m) east along levee road from Bench Mark 3624 B 1977, 17 feet (5.2
m) NE of centerline of road leading to Pacific Mariculture levee, 7.2 feet (2.2
m) NW from west corner post of fence running to NE side of access road leading
to levee, and 0.4 foot (0.1 m) below grade. The bench mark is on a rod driven
to 64 feet (19.5 m) and inside a PVC pipe.
BENCH MARK STAMPING: 3624 D 1977
MONUMENTATION: Survey Disk VM#: 8066
AGENCY: PID:
SETTING CLASSIFICATION: Copper-Clad Steel Rod
The bench mark is NNE of NNE corner of easternmost of two barns in line with
each other, SE of Pacific Mariculture building, 350 feet (107 m) WSW from Bench
Mark 3624 C 1977, 3.5 feet (1.1 m) ENE of a witness post, 1 foot (0.3 m) NW of a
fence post, and flush with the grade. The bench mark is on a rod driven to 56
feet (17 m) and encased in a PVC pipe.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 05/03/1983
Station ID: 9413624 SUPERCEDED DATE: 04/21/2003
Name: ELKHORN SLOUGH, PACIFICMARICULTURE DOCK
CALIFORNIA
NOAA Chart: 18680 Latitude: 36° 38.8' N
USGS Quad: MOSSLANDING Longitude: 121° 45.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3624 E 1977
MONUMENTATION: Survey Disk VM#: 8067
AGENCY: PID:
SETTING CLASSIFICATION: Copper-Clad Steel Rod
The bench mark is 300 feet (91.4 m) SW of Pacific Mariculture facility, 260 feet
(79.2 m) WSW of Bench Mark 3624 A 1977, 160 feet (48.8 m) west of Y-junction of
levee roads, 3.1 feet (0.9 m) NE of No Hunting or Shooting, County Ordinance,
sign, 0.8 foot (0.2 m) from top of pipe, and 0.5 foot (0.2 m) below the grade.
The bench mark is on a rod driven to 88 feet (27 m) and encased in a PVC pipe.
BENCH MARK STAMPING: NO STAMPING 1
MONUMENTATION: Survey Disk VM#: 8068
AGENCY: PID:
SETTING CLASSIFICATION: Utility Pole
The bench mark is set in the east face of a utility pole, on west side of levee
road leading to hatchery shed, NW of Bench Mark 3624 A 1977, 120 feet (36.6 m)
south of the shed and 0.5 foot (0.2 m) above ground.
BENCH MARK STAMPING: NO STAMPING 2
MONUMENTATION: Survey Disk VM#: 8069
AGENCY: PID:
SETTING CLASSIFICATION: Utility Pole
The bench mark is in the west face of a utility pole located at the SW corner of
the hatchery shed NW of Bench Mark 3624 A 1977 and 0.5 foot (0.2 m) above
ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 05/03/1983
Station ID: 9413624 SUPERCEDED DATE: 04/21/2003
Name: ELKHORN SLOUGH, PACIFICMARICULTURE DOCK
CALIFORNIA
NOAA Chart: 18680 Latitude: 36° 38.8' N
USGS Quad: MOSSLANDING Longitude: 121° 45.5' W
T I D A L D A T U M S
Tidal datums at ELKHORN SLOUGH, PACIFICMARICULTURE DOCK based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: APRIL-MAY 1977
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 9413450 MONTEREY, CA
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (05/31/1977) = 6.40
MEAN HIGHER HIGH WATER MHHW = 5.39
MEAN HIGH WATER MHW = 4.72
MEAN TIDE LEVEL MTL = 2.91
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 2.69
MEAN LOW WATER MLW = 1.09
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (05/05/1977) = -1.66
* NGVD reference based on adjustment of 1976 and NOS levels of1977.
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
3624 A 1977 8.91 4.19
3624 B 1977 9.46 4.74
3624 C 1977 11.75 7.03
3624 D 1977 13.32 8.60
3624 E 1977 8.94 4.22
NO STAMPING 1 9.49 4.77
NO STAMPING 2 8.33 3.61
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 05/03/1983
Station ID: 9413624 SUPERCEDED DATE: 04/21/2003
Name: ELKHORN SLOUGH, PACIFICMARICULTURE DOCK
CALIFORNIA
NOAA Chart: 18680 Latitude: 36° 38.8' N
USGS Quad: MOSSLANDING Longitude: 121° 45.5' W
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 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.