U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
PUBLICATION DATE: 09/03/1991
Station ID: 8779750 SUPERCEDED DATE: 04/21/2003
Name: SOUTH PADRE ISLAND, BRAZOS SANTIAGO PASS
TEXAS
NOAA Chart: 11301 Latitude: 26° 4.1' N
USGS Quad: PORT ISABEL Longitude: 97° 9.4' W
To reach the tidal bench marks from the intersection of Queen Isabella Causeway
and Padre Boulevard (also known as Texas State Park Road 100) in South Padre
Island proceed SE on Padre Boulevard to the Isla Blanca Park complex, continue
SE on the winding road to Jetties Restaurant and Lounge. The bench marks are on
the jetty, in the Isla Blanca Park complex, and at Texas Southmost College
(former U.S. Coast Guard Station). The tide gauge sensor and staff are in the
pass, SE of bench mark 1934 C-L 1+000.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 2
MONUMENTATION: Survey Disk VM#: 1700
AGENCY: PID#: AB1243
SETTING CLASSIFICATION: Boulder in a Jetty
The primary bench mark is set in the top and center of the rock jetty at the
south end of Padre Island, 68 feet (21 m) east of Bench Mark 1 and 2.7 feet (0.8
m) north of the NW corner of the southernmost concrete block.
BENCH MARK STAMPING: 1934 C-L 1+000
MONUMENTATION: Survey Disk VM#: 1695
AGENCY: PID:
SETTING CLASSIFICATION: Boulder in a Jetty
The bench mark is set in a granite boulder in the rock jetty at the south end of
South Padre Island, 191 feet (52 m) west of the south corner of Jetties
Restaurant and Lounge, 185.0 feet (56.4 m) SW of the SE corner of the building
housing restrooms, 63 feet (19 m) NW of power pole #CPL 36-35, and about level
with the top of the jetty.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
PUBLICATION DATE: 09/03/1991
Station ID: 8779750 SUPERCEDED DATE: 04/21/2003
Name: SOUTH PADRE ISLAND, BRAZOS SANTIAGO PASS
TEXAS
NOAA Chart: 11301 Latitude: 26° 4.1' N
USGS Quad: PORT ISABEL Longitude: 97° 9.4' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: N 1142 1959
MONUMENTATION: Survey Disk VM#: 1696
AGENCY: PID#: AB0258
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set in the top of a concrete foundation at the Texas Southmost
College (former U.S. Coast Guard Station office building) at the south end of
South Padre Island, 28 feet (9 m) SW of the centerline of the road around the
building, 2.4 feet (0.7 m) north of the east corner of the building, and about 1
foot (0.3 m) above the ground.
BENCH MARK STAMPING: 9750 B 1982
MONUMENTATION: Survey Disk VM#: 1697
AGENCY: PID:
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is in the Isla Blanca Park complex between Daniel L. Rocker and
Enrique N. Carrizales Roads, 282 feet (86 m) SW of the SW corner of restrooms,
50 feet (15 m) NNW of the centerline of a dead end street leading into the
mobile home park, 30 feet (9 m) south of Padre Boulevard, and 22.5 feet (6.9 m)
ESE of an aluminum light pole. The bench mark is 1 foot (0.3 m) below ground,
crimped to a stainless steel rod driven 60 feet (18 m) to substantial
resistance, and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
PUBLICATION DATE: 09/03/1991
Station ID: 8779750 SUPERCEDED DATE: 04/21/2003
Name: SOUTH PADRE ISLAND, BRAZOS SANTIAGO PASS
TEXAS
NOAA Chart: 11301 Latitude: 26° 4.1' N
USGS Quad: PORT ISABEL Longitude: 97° 9.4' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: S 1406 1982
MONUMENTATION: Metal Rod VM#: 1698
AGENCY: PID#: AB1240
SETTING CLASSIFICATION: Stainless Steel Rod in Sleeve
The bench mark is in the Isla Blanca Park complex near a large pavillion, 214
feet (65 m) east of the centerline of the paved road at the entrance to the
parking lot, 185 feet (56 m) ESE of power pole #20, 134.0 feet (40.8 m) west of
the SE corner of the patio at the pavillion, and 6 feet (2 m) SW of the patio
wall at the SW corner of the pavillion. The bench mark is 0.5 foot (0.2
m) below the ground and is the highest point of a stainless steel rod in sleeve
surrounded by a pipe with a stamped access cover.
BENCH MARK STAMPING: 1
MONUMENTATION: Survey Disk VM#: 1699
AGENCY: PID#: AB1242
SETTING CLASSIFICATION: Boulder in a Jetty
The bench mark is set in the top and center of the rock jetty at the south end
of Padre Island, 350 feet (107 m) SE of the SE corner of Jetties Restaurant and
Lounge.
BENCH MARK STAMPING: 3
MONUMENTATION: Survey Disk VM#: 1701
AGENCY: PID#: AB1244
SETTING CLASSIFICATION: Boulder in a Jetty
The bench mark is set in the top and center of the rock jetty at the south end
of Padre Island, 97 feet (30 m) east of Bench Mark 2.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
PUBLICATION DATE: 09/03/1991
Station ID: 8779750 SUPERCEDED DATE: 04/21/2003
Name: SOUTH PADRE ISLAND, BRAZOS SANTIAGO PASS
TEXAS
NOAA Chart: 11301 Latitude: 26° 4.1' N
USGS Quad: PORT ISABEL Longitude: 97° 9.4' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 5
MONUMENTATION: Survey Disk VM#: 1702
AGENCY: PID#: AB1238
SETTING CLASSIFICATION: Concrete Pavement
The bench mark is set in the concrete pavement at the Texas Southmost College
(former U.S. Coast Guard Station office building) at the south end of South
Padre Island, 40.0 feet (12.2 m) west of the road leading to the new Coast Guard
building, 4 feet (1 m) west of the east line of the building, 2 feet (1 m) west
of a set of steps, 1 foot (0.3 m) south of the north line of the building, and
about 2 feet (1 m) above ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
PUBLICATION DATE: 09/03/1991
Station ID: 8779750 SUPERCEDED DATE: 04/21/2003
Name: SOUTH PADRE ISLAND, BRAZOS SANTIAGO PASS
TEXAS
NOAA Chart: 11301 Latitude: 26° 4.1' N
USGS Quad: PORT ISABEL Longitude: 97° 9.4' W
T I D A L D A T U M S
Tidal datums at SOUTH PADRE ISLAND, BRAZOS SANTIAGO PASS based on:
LENGTH OF SERIES: 102 MONTHS
TIME PERIOD: 1980-1989
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8779770 PORT ISABEL
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (09/20/1967) = 7.40
MEAN HIGHER HIGH WATER MHHW = 1.58
MEAN HIGH WATER MHW = 1.51
MEAN TIDE LEVEL MTL = 0.86
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 0.85
MEAN LOW WATER MLW = 0.20
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (12/13/1989) = -1.81
* NGVD reference based on elevations published in Quad 260972, 1966, and NOS
leveling of 1991.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
2 5.65 4.14
1934 C-L 1+000 5.84 4.33
N 1142 1959 4.75 3.24
9750 B 1982 7.17 5.66
S 1406 1982 9.77 8.26
1 5.93 4.42
3 5.56 4.05
NO 5 4.73 3.22
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
PUBLICATION DATE: 09/03/1991
Station ID: 8779750 SUPERCEDED DATE: 04/21/2003
Name: SOUTH PADRE ISLAND, BRAZOS SANTIAGO PASS
TEXAS
NOAA Chart: 11301 Latitude: 26° 4.1' N
USGS Quad: PORT ISABEL Longitude: 97° 9.4' 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.