U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8771262 PUBLICATION DATE: 07/07/2021
Name: TEXAS CITY, GALVESTON BAY
NOAA Chart: 11324 Latitude: 29° 23.4' N ( 29.39060)
USGS Quad: TEXAS CITY Longitude: 94° 53.1' W ( -94.88490)
To reach from the U.S. Post Office at 2002 11th Ave N, in Texas City, TX, turn
left onto 21st St N and head south for 0.21 Km (0.13 mi) to 9th Ave. N., turn
left onto 9th Ave. N. (TX 1764) and proceed East for 3.1 Km (1.9 mi) to Bay St.
N., turn right onto Bay St. N. and proceed south for 0.11 Km (0.07 mi) to Texas
City Dike Rd, turn left onto Texas City Disk Rd and proceed east for 0.83 Km
(0.52 mi) to the Tackle Time Boat Launch and First Lady Pavilion, turn left into
the parking lot and proceed northwest for 91.5 m (300 ft) to the northwest shore
of a small basin for the boat launch. The bench marks are located around the
boat launch area and along Bay St N. The tide gauge is located at the NW corner
of the concrete deck for the boat launch.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1262 A 2019
DESIGNATION: 877 1662 A
MONUMENTATION: Tidal Station disk VM#: 23380
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete dock OPUS PID#: BBGS41
LATITUDE: 29° 23.4' N ( 29.39047) LONGITUDE: 94° 53.1' W ( -94.88481)
The primary bench mark is a disk set in a concrete dock near the NW corner of
the tackle time boat launch along the NE side of Texas City Dike Road, 80.29 m
(263.4 ft) NNE of a power pole, 49.82 m (163.5 ft) north of a light pole, 49.27
m (161.6 ft) east of the NE corner of First Lady Pavilion, 23.31 m (76.5 ft) NW
of the SE corner of a concrete dock, 19.24 m (63.1 ft) NW of a light pole and
8.65 m (28.4 ft) ESE of a 20 cm (8 inches) steel post with block and tackle.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8771262 PUBLICATION DATE: 07/07/2021
Name: TEXAS CITY, GALVESTON BAY
NOAA Chart: 11324 Latitude: 29° 23.4' N ( 29.39060)
USGS Quad: TEXAS CITY Longitude: 94° 53.1' W ( -94.88490)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Y 170 ELEV. 12.480 FT. 1936
DESIGNATION: Y 170
MONUMENTATION: Bench Mark disk VM#: 23381
AGENCY: US Coast and Geodetic Survey (USCGS) IDB PID#: AW1636
SETTING CLASSIFICATION: Sea wall OPUS PID#: AW1636
LATITUDE: 29° 23.5' N ( 29.39239) LONGITUDE: 94° 53.6' W ( -94.89328)
The bench mark is a disk set in a concrete wall near the SE corner of Bay St N
and Texas City Dike Road, 36.52 m (119.8 ft) ESE of a hydrant at the NW corner
of the intersection, 35.83 m (117.6 ft) east of wooden power pole f33214100a
near the SW corner of the intersection, 30.26 m (99.3 ft) east of a steel power
pole near the SW corner of the intersection, 20.66 m (67.8 ft) south of a steel
power pole at the NE corner of the intersection, 17.30 m (56.8 ft) east of the
centerline of Bay St N, 9.50 m (31.2 ft) south of the centerline of Texas City
Dike Road and 5.03 m (16.5 ft) WNW of a power pole.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8771262 PUBLICATION DATE: 07/07/2021
Name: TEXAS CITY, GALVESTON BAY
NOAA Chart: 11324 Latitude: 29° 23.4' N ( 29.39060)
USGS Quad: TEXAS CITY Longitude: 94° 53.1' W ( -94.88490)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: M 1204 1973
DESIGNATION: M 1204
MONUMENTATION: Vertical Control disk VM#: 23382
AGENCY: National Geodetic Survey (NGS) IDB PID#: AW1327
SETTING CLASSIFICATION: Bulk head OPUS PID:
LATITUDE: 29° 24.4' N ( 29.40672) LONGITUDE: 94° 53.6' W ( -94.89350)
The bench mark is a disk set in a 76 cm (30 inches) x 55 cm (22 inches) tall
concrete wall along the eastern side of Bay St N, 40.37 m (132.4 ft) SSW of a
barber pole gas pipeline sign that reads 'mc-42c', 35.67 m (117.0 ft) SE of a
power pole, 30.42 m (99.8 ft) NNE of the center of a concrete culvert headwall,
20.07 m (65.8 ft) east of a palm tree on the western side of Bay St N, 17.40 m
(57.1 ft) SSE of a man hole and 7.50 m (24.6 ft) east of of the centerline of
Bay St N.
BENCH MARK STAMPING: 1262 B 2019
DESIGNATION: 877 1262 B
MONUMENTATION: Tidal Station disk VM#: 23383
AGENCY: National Ocean Service (NGS) IDB PID:
SETTING CLASSIFICATION: Foundation OPUS PID:
LATITUDE: 29° 23.4' N ( 29.38975) LONGITUDE: 94° 53.1' W ( -94.88547)
The bench mark is a disk set in the NE corner of a 1.2 m (3.9 ft) x 0.45 m (1.5
ft) x 0.6 m (2.0 ft) high concrete sign foundation along the SW side of Texas
City Dike Road, 65.44 m (214.7 ft) WSW of a light pole, 65.44 m (214.7 ft) south
of the SE corner of the First Lady Pavilion, 35.53 m (116.6 ft) east of a power
pole with a light, 34.68 m (113.8 ft) ESE of a power pole with a light and 24.71
m (81.1 ft) WSW of a power pole.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8771262 PUBLICATION DATE: 07/07/2021
Name: TEXAS CITY, GALVESTON BAY
NOAA Chart: 11324 Latitude: 29° 23.4' N ( 29.39060)
USGS Quad: TEXAS CITY Longitude: 94° 53.1' W ( -94.88490)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1262 C 2019
DESIGNATION: 877 1262 C
MONUMENTATION: Tidal Station disk VM#: 23384
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete wall OPUS PID:
LATITUDE: 29° 23.9' N ( 29.39883) LONGITUDE: 94° 53.6' W ( -94.89342)
The bench mark is a disk set in a 0.5 m (1.6 ft) wide concrete wall of a bridge
over a concrete spillway along the eastern side of Bay St N, 62.70 m (205.7 ft)
north of the centerline of the intersection of 14th Avenue and Bay St N, 54.06 m
(177.4 ft) north of a street lamp, 31.88 m (104.6 ft) south of a railroad spike
in the center of a 22-in (56 cm) wide wall, 26.45 m (86.8 ft) ENE of a power
pole, 22.64 m (74.3 ft) WSW of the SE end of the concrete spillway and 7.25 m
(23.8 ft) east of the centerline of Bay St N.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8771262 PUBLICATION DATE: 07/07/2021
Name: TEXAS CITY, GALVESTON BAY
NOAA Chart: 11324 Latitude: 29° 23.4' N ( 29.39060)
USGS Quad: TEXAS CITY Longitude: 94° 53.1' W ( -94.88490)
T I D A L D A T U M S
Tidal datums at TEXAS CITY, GALVESTON BAY based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: December 2019 - February 2020
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8771013 EAGLE POINT, GALVESTON BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.331
MEAN HIGH WATER MHW = 0.316
MEAN SEA LEVEL MSL = 0.182
MEAN TIDE LEVEL MTL = 0.168
MEAN LOW WATER MLW = 0.020
North American Vertical Datum NAVD88 = 0.015
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1262 A 2019 1.747 1.431
Y 170 ELEV. 12.480 FT. 1936 3.163 2.847
M 1204 1973 3.450 3.134
1262 B 2019 1.997 1.681
1262 C 2019 3.203 2.887
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8771262 PUBLICATION DATE: 07/07/2021
Name: TEXAS CITY, GALVESTON BAY
NOAA Chart: 11324 Latitude: 29° 23.4' N ( 29.39060)
USGS Quad: TEXAS CITY Longitude: 94° 53.1' W ( -94.88490)
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.