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National Ocean Service
Datums Page Page 1 of 6
Station ID: 8779724 PUBLICATION DATE: 05/06/2003
Name: QUEEN ISABELLA CAUSEWAY, PADRE ISLAND
TX
NOAA Chart: 11301 Latitude: 26° 4.7' N ( 26.07830)
USGS Quad: PORT ISABEL Longitude: 97° 10.2' W ( -97.17000)
To reach the tidal bench marks from the intersection of Queen Isabel Causeway
and Padre Boulevard (State Park Road 100) in South Padre Island, proceed SE on
Padre Boulevard for 0.6 km (0.4 mi) to the old State Park Road 100, turn right
and continue west on the old State Park Road 100 for 0.56 km (0.35 mi) to the
old Queen Isabel Causeway bridge (presently a state fishing pier). The bench
marks are located on the bridge, along Padre Boulevard, and at the abandoned
U.S. Coast Guard Station office building. The tide gage and staff were located
at the east end of the old causeway bridge.
T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8779724 PUBLICATION DATE: 05/06/2003
Name: QUEEN ISABELLA CAUSEWAY, PADRE ISLAND
TX
NOAA Chart: 11301 Latitude: 26° 4.7' N ( 26.07830)
USGS Quad: PORT ISABEL Longitude: 97° 10.2' W ( -97.17000)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: M 1142 1959
DESIGNATION: M 1142
MONUMENTATION: Bench Mark disk VM#: 7913
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AB0257
SETTING CLASSIFICATION: Concrete wing wall OPUS PID:
LATITUDE: 26° 4.7' N ( 26.07830) LONGITUDE: 97° 10.2' W ( -97.17000)
The primary bench mark is a disk set in the top of the concrete wingwall at the
east end of the old Queen Isabel Causeway, 17.34 m (56.9 ft) SE of the SE corner
of the state building, 15 m (49 ft) south of the centerline of the highway, 11 m
(36 ft) south of the south end of the east abutment, and level with the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8779724 PUBLICATION DATE: 05/06/2003
Name: QUEEN ISABELLA CAUSEWAY, PADRE ISLAND
TX
NOAA Chart: 11301 Latitude: 26° 4.7' N ( 26.07830)
USGS Quad: PORT ISABEL Longitude: 97° 10.2' W ( -97.17000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: N 1142 1959
DESIGNATION: N 1142
MONUMENTATION: Bench Mark disk VM#: 7914
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AB0258
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 26° 4.5' N ( 26.07500) LONGITUDE: 97° 9.9' W ( -97.16500)
The bench mark is a disk set in the top of a concrete foundation at the Texas
Southmost College (formerly the 1923 U.S. Coast Guard Station office building)
at the south end of South Padre Island, 8.53 m (28.0 ft) SW of the centerline of
the road around the building, 0.73 m (2.4 ft) north of the east corner of the
building, and 0.3 m (1 ft) above the ground.
BENCH MARK STAMPING: M 9724 1977
DESIGNATION: 877 9724 M TIDAL
MONUMENTATION: Tidal Station disk VM#: 7915
AGENCY: National Ocean Survey (NOS) IDB PID#: AB1237
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 26° 4.6' N ( 26.07670) LONGITUDE: 97° 9.9' W ( -97.16500)
The bench mark is a disk set in the top of the south corner of the most
southerly one of two abandoned concrete foundations for signs in a small grassy
area in front of Sea Ranch Grocery, 29.72 m (97.5 ft) east of the north corner
of Sea Ranch Grocery, 26.33 m (86.4 ft) north of the north corner of Sea Ranch
Motel, 24.32 m (79.8 ft) SW of the centerline of the highway, and 0.3 m (1 ft)
above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8779724 PUBLICATION DATE: 05/06/2003
Name: QUEEN ISABELLA CAUSEWAY, PADRE ISLAND
TX
NOAA Chart: 11301 Latitude: 26° 4.7' N ( 26.07830)
USGS Quad: PORT ISABEL Longitude: 97° 10.2' W ( -97.17000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 5
DESIGNATION: 877 9750 TIDAL 5
MONUMENTATION: Bench Mark disk VM#: 7916
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AB1238
SETTING CLASSIFICATION: Concrete pavement OPUS PID:
LATITUDE: 26° 4.7' N ( 26.07830) LONGITUDE: 97° 9.7' W ( -97.16170)
The bench mark is a disk set in the concrete pavement of the Texas Southmost
College South Padre Island Branch Building (formerly the 1923 U.S. Coast Guard
Station office building) located at the south end of South Padre Island, 12.19 m
(40.0 ft) west of the road leading to the new Coast Guard building, 1.22 m (4.0
ft) west of the east line of the building, 0.61 m (2.0 ft) west of a set of
steps, 0.3 m (1 ft) south of the north line of the building, and about 0.61 m
(2.0 ft) above ground.
BENCH MARK STAMPING: 8
DESIGNATION: 877 9724 TIDAL 8
MONUMENTATION: Survey disk VM#: 7917
AGENCY: Cameron County IDB PID#: AB1245
SETTING CLASSIFICATION: Concrete bridge railing OPUS PID:
LATITUDE: 26° 4.7' N ( 26.07830) LONGITUDE: 97° 10.2' W ( -97.17000)
The bench mark is a disk set in the base of the concrete railing at the east end
of the old Queen Isabel Causeway, 10.88 m (35.7 ft) NE of the NE corner of the
state building, 0.76 m (2.5 ft) west of the east end of the railing, and 0.24 m
(0.8 ft) above the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8779724 PUBLICATION DATE: 05/06/2003
Name: QUEEN ISABELLA CAUSEWAY, PADRE ISLAND
TX
NOAA Chart: 11301 Latitude: 26° 4.7' N ( 26.07830)
USGS Quad: PORT ISABEL Longitude: 97° 10.2' W ( -97.17000)
T I D A L D A T U M S
Tidal datums at QUEEN ISABELLA CAUSEWAY, PADRE ISLAND based on:
LENGTH OF SERIES: 12 MONTHS
TIME PERIOD: May 1977 - April 1978
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8779770 PORT ISABEL, LAGUNA MADRE
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (09/01/1977) = 1.100
MEAN HIGHER HIGH WATER MHHW = 0.391
MEAN HIGH WATER MHW = 0.375
MEAN SEA LEVEL MSL = 0.231
MEAN TIDE LEVEL MTL = 0.206
MEAN LOW WATER MLW = 0.038
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (01/19/1977) = -0.455
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
M 1142 1959 1.656 1.281
N 1142 1959 1.296 0.921
M 9724 1977 2.114 1.739
NO 5 1.311 0.936
8 2.447 2.072
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8779724 PUBLICATION DATE: 05/06/2003
Name: QUEEN ISABELLA CAUSEWAY, PADRE ISLAND
TX
NOAA Chart: 11301 Latitude: 26° 4.7' N ( 26.07830)
USGS Quad: PORT ISABEL Longitude: 97° 10.2' W ( -97.17000)
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.