U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 1 of 5
Station ID: 9415112 PUBLICATION DATE: 09/19/1983
Name: MALLARD ISLAND, SUISUN BAY
CALIFORNIA
NOAA Chart: 18656 Latitude: 38ø 2.6' N
USGS Quad: HONKER BAY Longitude: 121ø 55.1' W
To reach the tidal bench marks proceed west from Pittsburg on Highway 4, exit at
Willow Pass to West Pittsburg, left on Solano, continue to the end of the road,
right turn, then across the railroad tracks and follow the dirt road past the
pumphouse to the levee road. The bench marks are along the levee road. The
tide gage and staff were located at the end of the abandoned Mallard Ferry
wharf.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING:
MONUMENTATION: VM#: 8568
AGENCY: PID:
SETTING CLASSIFICATION:
BENCH MARK STAMPING: BM 1 1932
MONUMENTATION: Survey Disk VM#: 8559
AGENCY: PID#: JS1982
SETTING CLASSIFICATION: Concrete Base
The bench mark is in top of the NE corner of the concrete base of a standpipe
projecting 30 feet (9.1 m) above the ground, 130 feet (39.6 m) SW of the
California Water Service Companys Mallard pumping station, 24 feet (7.3 m) NW
of and across a wooden viaduct from the centerline of the road, and 1.5 feet
(0.5 m) above the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9415112 PUBLICATION DATE: 09/19/1983
Name: MALLARD ISLAND, SUISUN BAY
CALIFORNIA
NOAA Chart: 18656 Latitude: 38ø 2.6' N
USGS Quad: HONKER BAY Longitude: 121ø 55.1' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BM 3 1932
MONUMENTATION: Survey Disk VM#: 8560
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Culvert
The bench mark is set horizontally in concrete on top of a concrete culvert
under a dirt road leading to a pumphouse east of the road, 82 feet (25 m) south
of Bench Mark 1 1932, 29.5 feet (9.0 m) east of the center of a square gate, 18
feet (5.5 m) north of a telephone pole, 16.5 feet (5.0 m) from the NE corner of
the culvert along the north wall of the culvert, and 2.5 feet (0.5 m) above the
ground.
BENCH MARK STAMPING: 5112 E 1977
MONUMENTATION: Survey Disk VM#: 8561
AGENCY: PID:
SETTING CLASSIFICATION: Rod Mark
The bench mark is 0.4 mile (0.55 km) north along the dirt road from Bench Mark 1
1932, 50 feet (15.2 m) east of the east edge of the slough on the west side of
the road in a 20 foot (6.1 m) clearing 10 feet (3.0 m) west of the centerline
of the road, and 3 feet (0.9 m) NNE of a redwood witness post. The bench mark
is on a rod driven to 56 feet (17.1 m), crimped to the top of a rod at ground
level, and surrounded by a PVC projecting 0.5 foot (0.2 m) and concrete
kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9415112 PUBLICATION DATE: 09/19/1983
Name: MALLARD ISLAND, SUISUN BAY
CALIFORNIA
NOAA Chart: 18656 Latitude: 38ø 2.6' N
USGS Quad: HONKER BAY Longitude: 121ø 55.1' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5112 F 1977
MONUMENTATION: Survey Disk VM#: 8562
AGENCY: PID:
SETTING CLASSIFICATION: Rod Mark
The bench mark is 0.2 mile (0.32 km) NE along the dirt levee road from Bench
Mark 5112 E on the south side of the road, 10 feet (3.0 m) south of the
centerline of the road, and 4 feet (1.2 m) ENE of a redwood witness post. The
bench mark is on a rod driven to 5.9 feet (18 m), level with the ground,
surrounded by a PVC pipe projecting 0.5 foot (0.2 m) and a concrete kickblock.
BENCH MARK STAMPING: 5112 G 1977
MONUMENTATION: Survey Disk VM#: 8563
AGENCY: PID:
SETTING CLASSIFICATION: Rod Mark
The bench mark is 0.34 mile (0.55 km) east of Bench Mark 5112 F 1977, along the
south side of the levee road, 10 feet (3.0 m) south of the road, and 4 feet
(1.2 m) north of a telephone pole. The bench mark is on a rod driven to 63
feet (19.2 m), surrounded by a PVC pipe projecting 0.6 foot (0.2 m) and a
concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9415112 PUBLICATION DATE: 09/19/1983
Name: MALLARD ISLAND, SUISUN BAY
CALIFORNIA
NOAA Chart: 18656 Latitude: 38ø 2.6' N
USGS Quad: HONKER BAY Longitude: 121ø 55.1' W
T I D A L D A T U M S
Tidal datums at MALLARD ISLAND, SUISUN BAY based on:
LENGTH OF SERIES: 15 MONTHS
TIME PERIOD: JULY 1977-SEPTEMBER 1978
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 9415144 PORT CHICAGO
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (01/16/1978) = 6.08
MEAN HIGHER HIGH WATER (MHHW) = 4.10
MEAN HIGH WATER (MHW) = 3.61
MEAN TIDE LEVEL (MTL) = 2.10
MEAN LOW WATER (MLW) = 0.60
MEAN LOWER LOW WATER (MLLW) = 0.00
LOWEST OBSERVED WATER LEVEL (05/27/1983) = -0.81
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
0 0.00 0.00
BM 1 1932 9.30 5.69
BM 3 1932 5.24 1.63
5112 E 1977 6.52 2.91
5112 F 1977 8.12 4.51
5112 G 1977 7.88 4.27
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9415112 PUBLICATION DATE: 09/19/1983
Name: MALLARD ISLAND, SUISUN BAY
CALIFORNIA
NOAA Chart: 18656 Latitude: 38ø 2.6' N
USGS Quad: HONKER BAY Longitude: 121ø 55.1' 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 (NAVD 88).
NGVD 29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded. NGVD 29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads. NGVD 29 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 NGVD 29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at
National Geodetic Survey.
NAVD 88 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. NAVD 88 replaces NGVD 29 as the national
standard geodetic reference for heights. Bench mark elevations relative to
NAVD 88 are available from NGS through the World Wide Web at
National Geodetic Survey.
NGVD 29 and NAVD 88 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 NAVD 88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD 88 elevations.
The NAVD 88 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, NAVD 88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD 88 elevations listed for
each bench mark in the NGS database.