U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 8771328 PUBLICATION DATE: 04/21/2003
Name: PORT BOLIVAR, BOLIVAR ROADS
TX
NOAA Chart: 11324 Latitude: 29° 21.9' N ( 29.36500)
USGS Quad: GALVESTON Longitude: 94° 46.8' W ( -94.78000)
To reach the tidal bench marks from the Point Bolivar ferry landing, proceed
east on State Highway 87 to the first asphalt road on the left (Frenchtown
Road), turn left on Frenchtown Road, continue north for 0.4 km (0.2 mi) to a
road on the left, turn left and follow the road to a fish house. The bench
marks are located along the road leading to the fish house. The tide gage is
located near the NW corner of the big dock.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: LUB 1328 A 1994
DESIGNATION: 877 1328 A
MONUMENTATION: Bench Mark disk VM#: 13635
AGENCY: Lamar University IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 21.9' N ( 29.36500) LONGITUDE: 94° 46.8' W ( -94.78000)
The primary bench mark is a disk set on the south side of the gravel/shell road
leading to the fishing dock, 91 m (300 ft) SE of the tide gage on the dock, and
0.61 m (2.0 ft) SSE of a power pole. The bench mark is crimped to the top of a
stainless steel rod driven an unspecified depth to refusal, and encased in a
6-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 8771328 PUBLICATION DATE: 04/21/2003
Name: PORT BOLIVAR, BOLIVAR ROADS
TX
NOAA Chart: 11324 Latitude: 29° 21.9' N ( 29.36500)
USGS Quad: GALVESTON Longitude: 94° 46.8' W ( -94.78000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: LUB 1328 B 1994
DESIGNATION: 877 1328 B
MONUMENTATION: Bench Mark disk VM#: 13636
AGENCY: Lamar University IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 21.9' N ( 29.36500) LONGITUDE: 94° 46.8' W ( -94.78000)
The bench mark is a disk set on the south side of the gravel/shell road leading
to the fishing dock, 59.44 m (195.0 ft) ENE of bench mark LUB 1328 A 1994, and 1
m (3 ft) south of a power pole. The bench mark is crimped to the top of a
stainless steel rod driven an unspecified depth to refusal, and encased in a
6-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: LUB 1328 C 1994
DESIGNATION: 877 1328 C
MONUMENTATION: Bench Mark disk VM#: 13637
AGENCY: Lamar University IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BBBS78
LATITUDE: 29° 21.9' N ( 29.36500) LONGITUDE: 94° 46.8' W ( -94.78000)
The bench mark is a disk set on the SE side of the gravel/shell road leading to
the fishing dock, 53.34 m (175.0 ft) NE of bench mark LUB 1328 B 1994, and 1 m
(3 ft) south of a power pole. The bench mark is crimped to the top of a
stainless steel rod driven an unspecified depth to refusal, and encased in a
6-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8771328 PUBLICATION DATE: 04/21/2003
Name: PORT BOLIVAR, BOLIVAR ROADS
TX
NOAA Chart: 11324 Latitude: 29° 21.9' N ( 29.36500)
USGS Quad: GALVESTON Longitude: 94° 46.8' W ( -94.78000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: LUB 1328 D 1994
DESIGNATION: 877 1328 D
MONUMENTATION: Bench Mark disk VM#: 13638
AGENCY: Lamar University IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 21.9' N ( 29.36500) LONGITUDE: 94° 46.8' W ( -94.78000)
The bench mark is a disk set on the north side of the asphalt road leading to
the fishing dock, 143 m (470 ft) north of bench mark LUB 1328 C 1994, 23 m (75
ft) north of the road, and 1 m (3 ft) south of a power pole. The bench mark is
crimped to the top of a stainless steel rod driven an unspecified depth to
refusal, and encased in a 6-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: LUB 1328 E 1994
DESIGNATION: 877 1328 E
MONUMENTATION: Bench Mark disk VM#: 13639
AGENCY: Lamar University IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 21.9' N ( 29.36500) LONGITUDE: 94° 46.8' W ( -94.78000)
The bench mark is a disk set on the north side of the asphalt road leading to
the fishing dock, 44 m (145 ft) east of bench mark LUB 1328 D 1994, and 1.07 m
(3.5 ft) south of a power pole. The bench mark is crimped to the top of a
stainless steel rod driven an unspecified depth to refusal, and encased in a
6-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8771328 PUBLICATION DATE: 04/21/2003
Name: PORT BOLIVAR, BOLIVAR ROADS
TX
NOAA Chart: 11324 Latitude: 29° 21.9' N ( 29.36500)
USGS Quad: GALVESTON Longitude: 94° 46.8' W ( -94.78000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: LUB 1328 F 1997
DESIGNATION: 877 1328 F
MONUMENTATION: Bench Mark disk VM#: 13640
AGENCY: Lamar University IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 21.9' N ( 29.36500) LONGITUDE: 94° 46.8' W ( -94.78000)
The bench mark is a disk set 46.21 m (151.6 ft) WSW of the SW corner of the Port
Bolivar Fisheries Dock/processing building, 45.00 m (147.6 ft) WNW of the NW
corner of the Port Bolivar Fisheries office building, 39.62 m (130.0 ft) SSE of
the SE corner of the tide gage platform. The bench mark is crimped to the top
of a stainless steel rod driven 15.2 m (50 ft) to refusal, and encased in a
6-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8771328 PUBLICATION DATE: 04/21/2003
Name: PORT BOLIVAR, BOLIVAR ROADS
TX
NOAA Chart: 11324 Latitude: 29° 21.9' N ( 29.36500)
USGS Quad: GALVESTON Longitude: 94° 46.8' W ( -94.78000)
T I D A L D A T U M S
Tidal datums at PORT BOLIVAR, BOLIVAR ROADS based on:
LENGTH OF SERIES: 5 Years
TIME PERIOD: January 1996 - December 2000
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8771450 GALVESTON PIER 21, GALVESTON CHANNEL
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (09/11/1998) = 1.627
MEAN HIGHER HIGH WATER MHHW = 0.426
MEAN HIGH WATER MHW = 0.402
MEAN SEA LEVEL MSL = 0.258
MEAN TIDE LEVEL MTL = 0.230
MEAN LOW WATER MLW = 0.059
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (12/29/1997) = -1.081
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
LUB 1328 A 1994 2.461 2.059
LUB 1328 B 1994 1.993 1.591
LUB 1328 C 1994 2.100 1.698
LUB 1328 D 1994 1.296 0.894
LUB 1328 E 1994 1.423 1.021
LUB 1328 F 1997 2.332 1.930
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8771328 PUBLICATION DATE: 04/21/2003
Name: PORT BOLIVAR, BOLIVAR ROADS
TX
NOAA Chart: 11324 Latitude: 29° 21.9' N ( 29.36500)
USGS Quad: GALVESTON Longitude: 94° 46.8' W ( -94.78000)
Foot Notes:
Galveston Bay, Texas has anomalous relative sea level trends compared to most
other geographic regions in the United States. This is due to a general
subsidence of land in this region, which has been occurring at a rapid rate.
Because of the magnitude of the sea level trends in these areas, NOAA has
adopted a procedure for computing accepted tidal datums for the National Water
Level Observation Network (NWLON) using the last several years of sea level data
rather than the 19 - year tidal epoch. The tide ranges are still based on the
1983 - 2001 National Tidal Datum Epoch (NTDE) and are applied to the five year
(1997 - 2001) mean tide level (MTL) to compute other tidal datums. The adoption
of this procedure was necessary to ensure that these tidal datums accurately
represent the existing stand of sea level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8771328 PUBLICATION DATE: 04/21/2003
Name: PORT BOLIVAR, BOLIVAR ROADS
TX
NOAA Chart: 11324 Latitude: 29° 21.9' N ( 29.36500)
USGS Quad: GALVESTON Longitude: 94° 46.8' W ( -94.78000)
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.