U.S. DEPARTMENT OF COMMERCE
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National Ocean Service
Datums Page Page 1 of 5
Station ID: 8761484 PUBLICATION DATE: 04/27/2018
Name: LEASE VB #4, BAYOU DULAC
LA
NOAA Chart: 11364 Latitude: 29° 27.4' N ( 29.45670)
USGS Quad: BAY BATISTE Longitude: 89° 48.0' W ( -89.80000)
To reach the tidal bench marks by boat from Hi Ridge Marina on the north side of
Port Sulphur, proceed SW on the marina canal to Grand Bayou, then turn right and
proceed NW on Grand Bayou for 5.1 km (3.2 mi) to Socola Canal #2, then turn left
and proceed SW on the canal to and across Bay Sansbois for 5.6 km (3.5 mi), then
enter Bayou Dulac and continue west for about 1.6 km (1.0 mi) to Angelo Camp
with Lease V.B. #4 sign on its front (south) side on the right, with a small
bayou along the east side of the camp. The bench marks are located in the
vicinity of the camp and westward along the same continuous section of marsh
that the camp is on. The gage and staff were on the front wharf of Angelo Camp.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1484 A 1985
DESIGNATION: 876 1484 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 7166
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 27.4' N ( 29.45670) LONGITUDE: 89° 48.0' W ( -89.80000)
The primary bench mark is a disk located in the marsh just west of Angelo Camp,
18.17 m (59.6 ft) NNW of the NW corner pile supporting Angelo Camp, 7.56 m (24.8
ft) west of the face of the NW corner pile supporting the water tank at the rear
of the camp, and 0.40 m (1.3 ft) south of an NOS witness post. The bench mark
is set 0.21 m (0.7 ft) above ground level, crimped to the top of a stainless
steel rod driven 21.9 m (72 ft) to substantial resistance, and encased in a
5-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8761484 PUBLICATION DATE: 04/27/2018
Name: LEASE VB #4, BAYOU DULAC
LA
NOAA Chart: 11364 Latitude: 29° 27.4' N ( 29.45670)
USGS Quad: BAY BATISTE Longitude: 89° 48.0' W ( -89.80000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1484 B 1985
DESIGNATION: 876 1484 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 7167
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 27.4' N ( 29.45670) LONGITUDE: 89° 48.0' W ( -89.80000)
The bench mark is a disk located 76.29 m (250.3 ft) west of bench mark 1484 A
1985, 6 m (20 ft) north of the north bank of Bayou Dulac, 5 m (18 ft) west of a
2-inch square wood post standing 2 m (7 ft) above the marsh, 3.66 m (12.0 ft)
south of a 2-inch square wood post standing 2 m (7 ft) above the marsh, and 0.37
m (1.2 ft) south of an NOS witness post. The bench mark is set 12 cm (0.4 ft)
above ground level, crimped to the top of a stainless steel rod driven 24.4 m
(80 ft) to substantial resistance, and encased in a 5-inch PVC pipe and concrete
kickblock.
BENCH MARK STAMPING: 1484 C 1985
DESIGNATION: 876 1484 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 7168
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 27.4' N ( 29.45670) LONGITUDE: 89° 48.0' W ( -89.80000)
The bench mark is a disk located 76.20 m (250.0 ft) west of bench mark 1484 B
1985, 7.10 m (23.3 ft) south of a 2-inch square wood post standing 2 m (7 ft)
above the marsh, 6.77 m (22.2 ft) north of the north bank of Bayou Dulac, 3.35 m
(11.0 ft) west of a 2-inch square wood post standing 2 m (7 ft) above the marsh,
and 0.37 m (1.2 ft) south of an NOS witness post. The bench mark is set 0.15 m
(0.5 ft) above ground level, crimped to the top of a stainless steel rod driven
20.7 m (68 ft) to substantial resistance, and encased in a 5-inch PVC pipe and
concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8761484 PUBLICATION DATE: 04/27/2018
Name: LEASE VB #4, BAYOU DULAC
LA
NOAA Chart: 11364 Latitude: 29° 27.4' N ( 29.45670)
USGS Quad: BAY BATISTE Longitude: 89° 48.0' W ( -89.80000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1484 D 1985
DESIGNATION: 876 1484 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 7169
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 27.4' N ( 29.45670) LONGITUDE: 89° 48.0' W ( -89.80000)
The bench mark is a disk located 76.2 m (250.0 ft) west of bench mark 1484 C
1985, 11.46 m (37.6 ft) NE of the NW corner pile supporting Camp Lease B-14,
6.19 m (20.3 ft) north of the NE face of the NE corner pile, 3.81 m (12.5 ft) NE
of the NE corner pile supporting the generator shed, and 0.37 m (1.2 ft) SE of
an NOS witness post. The bench mark is set 12 cm (0.4 ft) above ground level,
crimped to the top of a stainless steel rod driven 20.7 m (68 ft) to refusal,
and encased in a 5-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 1484 E 1985
DESIGNATION: 876 1484 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 7170
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 27.4' N ( 29.45670) LONGITUDE: 89° 48.0' W ( -89.80000)
The bench mark is a disk located 76.20 m (250.0 ft) NW of bench mark 1484 D
1985, 69.49 m (228.0 ft) NW of the NW corner pile supporting the water tank at
the rear of Camp Lease B-14, 22 m (73 ft) NE of the bank of a small north-south
canal immediately west of Camp Lease B-14, 7.71 m (25.3 ft) SW of a 2-inch
square wood post standing 2 m (7 ft) above the marsh, 4.51 m (14.8 ft) NW of a
2-inch square wood post standing 2 m (7 ft) above the marsh, and 0.37 m (1.2 ft)
SW of an NOS witness post. The bench mark is set 9 cm (0.3 ft) above ground
level, crimped to the top of a stainless steel rod driven 20.7 m (68 ft) to
refusal, and encased in a 5-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8761484 PUBLICATION DATE: 04/27/2018
Name: LEASE VB #4, BAYOU DULAC
LA
NOAA Chart: 11364 Latitude: 29° 27.4' N ( 29.45670)
USGS Quad: BAY BATISTE Longitude: 89° 48.0' W ( -89.80000)
T I D A L D A T U M S
Tidal datums at LEASE VB #4, BAYOU DULAC based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: September 1985 - August 1986
TIDAL EPOCH: 2012-2016
CONTROL TIDE STATION: 8761724 GRAND ISLE, EAST POINT
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/28/1985) = 1.371
MEAN HIGHER HIGH WATER MHHW = 0.320
MEAN HIGH WATER MHW = 0.319
MEAN SEA LEVEL MSL = 0.164
MEAN TIDE LEVEL MTL = 0.163
MEAN LOW WATER MLW = 0.006
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (03/01/1986) = -0.738
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1484 A 1985 0.176 -0.143
1484 B 1985 0.164 -0.155
1484 C 1985 0.123 -0.196
1484 D 1985 0.130 -0.189
1484 E 1985 0.092 -0.227
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8761484 PUBLICATION DATE: 04/27/2018
Name: LEASE VB #4, BAYOU DULAC
LA
NOAA Chart: 11364 Latitude: 29° 27.4' N ( 29.45670)
USGS Quad: BAY BATISTE Longitude: 89° 48.0' W ( -89.80000)
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.