U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 9
Station ID: 8762482 PUBLICATION DATE: 01/08/2021
Name: WEST BANK 1, BAYOU GAUCHE
LA
NOAA Chart: 11352 Latitude: 29° 47.3' N ( 29.78861)
USGS Quad: DES ALLEMANDS Longitude: 90° 25.2' W ( -90.42028)
From the intersection of Interstate 310 South and US Highway 90 West, proceed
west on US Highway 90 for 4.8 km (3.0 mi) to the intersection of LA 306, take LA
306 South for 9.6 km (6.0 mi) to Bayou Gauche, LA. The tide gauge and benchmarks
are in the vicinity of the Bayou Gauche Volunteer Fire Department Boat house.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 2482 A 2003
DESIGNATION: 876 2482 A
MONUMENTATION: Tidal Station disk VM#: 17092
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 47.3' N ( 29.78864) LONGITUDE: 90° 25.2' W ( -90.41986)
The primary bench mark is a disk located 7.30 m (23.95 ft) SSW from the
centerline of LA HWY 306, 6.85 m (22.47 ft) NNE from the NE corner of the
boathouse, 1.81 m (5.94 ft) east of a power pole, and 0.84 m (2.76 ft) NE of a
orange witness post, driven 25.1 m (82.3 ft) to refusal and encased in 5" PVC
pipe with a concrete kick block.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 9
Station ID: 8762482 PUBLICATION DATE: 01/08/2021
Name: WEST BANK 1, BAYOU GAUCHE
LA
NOAA Chart: 11352 Latitude: 29° 47.3' N ( 29.78861)
USGS Quad: DES ALLEMANDS Longitude: 90° 25.2' W ( -90.42028)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2482 B 2003
DESIGNATION: 876 2482 B
MONUMENTATION: Tidal Station disk VM#: 17093
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 47.3' N ( 29.78883) LONGITUDE: 90° 25.2' W ( -90.41958)
The bench mark is tidal disk located 6.85 m (22.47 ft) NNE from the centerline
of LA HWY 306, 6.05 m (19.85 ft) WSW from the SW corner of the residence at
3629, 1.50 m (4.92 ft) NNW of a power pole, and 0.45 m (1.48 ft) WSW from an
orange withness post, driven 26.82 m (87.99 ft) to refusal and encased in 5" PVC
pipe with a concrete kick block.
BENCH MARK STAMPING: 2482 C 2003
DESIGNATION: 876 2482 C
MONUMENTATION: Tidal Station disk VM#: 17094
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 47.4' N ( 29.78972) LONGITUDE: 90° 25.3' W ( -90.42144)
The bench mark is a disk located 8.30 m (27.23 ft) west of the NW corner the
porch at residence NO. 3571, 5.60 m (18.37 ft) NNE of the centerline of LA HWY
306, 0.60 m (1.97 ft) NNW of a power pole, and 0.45 m (1.48 ft) SSW from an
orange withness post, driven 19.5 m (64.0 ft) to refusal and encased in 5" PVC
pipe with a concrete kick block.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 9
Station ID: 8762482 PUBLICATION DATE: 01/08/2021
Name: WEST BANK 1, BAYOU GAUCHE
LA
NOAA Chart: 11352 Latitude: 29° 47.3' N ( 29.78861)
USGS Quad: DES ALLEMANDS Longitude: 90° 25.2' W ( -90.42028)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2482 D 2003
DESIGNATION: 876 2482 D
MONUMENTATION: Tidal Station disk VM#: 17095
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Bridge foundation OPUS PID#: BBFX45
LATITUDE: 29° 47.4' N ( 29.79039) LONGITUDE: 90° 25.4' W ( -90.42325)
The bench mark is a disk set in a concrete bridge foundation located 10.40 m
(34.12 ft) SSW from power pole #710, 5.75 m (18.86 ft) NE from the centerline of
LA HWY 306, 0.55 m (1.80 ft) NNE from the NE corner of bridgewall footing, and
0.18 m (0.59 ft) SE from the NW side of bridge footing.
BENCH MARK STAMPING: 2482 E 2003
DESIGNATION: 876 2482 E
MONUMENTATION: Flange-encased Rod VM#: 17096
AGENCY: National Ocean Service (NOS) IDB PID#: DJ9385
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: DJ9385
LATITUDE: 29° 47.4' N ( 29.79061) LONGITUDE: 90° 25.4' W ( -90.42397)
The bench mark is a flange-encased rod located 43.7 m (143.4 ft) ESE from
Badeaux Lane, 28.5 m (93.5 ft) north of the NW corner of residence at #80, and
0.45 m (1.48 ft) north of a witness post, driven 20.7 m (67.9 ft) to refusal and
encased in 5" PVC and has a concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 9
Station ID: 8762482 PUBLICATION DATE: 01/08/2021
Name: WEST BANK 1, BAYOU GAUCHE
LA
NOAA Chart: 11352 Latitude: 29° 47.3' N ( 29.78861)
USGS Quad: DES ALLEMANDS Longitude: 90° 25.2' W ( -90.42028)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2482 G 2006
DESIGNATION: 876 2482 G
MONUMENTATION: Tidal Station disk VM#: 18282
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Steel rod OPUS PID#: BBCN89
LATITUDE: 29° 47.3' N ( 29.78806) LONGITUDE: 90° 25.1' W ( -90.41803)
The bench mark is a disk located along LA HWY 306, 78.94 m (258.99 ft) ESE of
bench mark 876 2482 F, 17.06 m (55.97 ft) ESE of the mailbox at 3683 LA HWY 306,
22.55 m (73.98 ft) WNW of of mailbox at 3701 LA 306, 9.44 m (30.97 ft) SSE of
the SE corner of the house at 3683 LA HWY 306, 4.57 m (14.99 ft) NE of center of
LA 306, and 0.60 m (1.97 ft) WSW of witness post. The datum point is the top of
a stainless steel rod driven 27.40 m (89.89 ft) to refusal, in a sleeve
extending to a depth of 0.91 m (2.99 ft) and encased in a 5-inch PVC pipe with
an aluminum cover and concrete kickblock. Note - sleeve depth does not meet the
specifications for class A rod mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 9
Station ID: 8762482 PUBLICATION DATE: 01/08/2021
Name: WEST BANK 1, BAYOU GAUCHE
LA
NOAA Chart: 11352 Latitude: 29° 47.3' N ( 29.78861)
USGS Quad: DES ALLEMANDS Longitude: 90° 25.2' W ( -90.42028)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2482 H 2006
DESIGNATION: 876 2482 H
MONUMENTATION: Tidal Station disk VM#: 18283
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Steel rod OPUS PID:
LATITUDE: 29° 47.3' N ( 29.78817) LONGITUDE: 90° 25.0' W ( -90.41697)
The bench mark is a disk located along LA HWY 306, 106.98 m (350.98 ft) SE of
bench mark 876 2482 G, 12.49 m (40.98 ft) south of utility pole (no number) in
front of 3727 LA HWY 306, 9.75 m (31.99 ft) NW of NW corner of dock across
street from 3727 LA HWY 306, 21.94 m (71.98 ft) west of mailbox at 3727 LA HWY
306, 5.18 m (16.99 ft) south of center of LA HWY 306, and 0.60 m (1.97 ft) north
of the witness post. The datum point is the top of a stainless steel rod driven
27.40 m (89.89 ft) to refusal, in a sleeve extending to a depth of 0.91 m (2.99
ft) and encased in a 5 -inch PVC pipe with an aluminum cover and concrete
kickblock. Note - Sleeve depth does not meet the specifications for class A rod
mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 9
Station ID: 8762482 PUBLICATION DATE: 01/08/2021
Name: WEST BANK 1, BAYOU GAUCHE
LA
NOAA Chart: 11352 Latitude: 29° 47.3' N ( 29.78861)
USGS Quad: DES ALLEMANDS Longitude: 90° 25.2' W ( -90.42028)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2482 K 2006
DESIGNATION: 876 2482 K
MONUMENTATION: Tidal Station disk VM#: 18284
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Steel rod OPUS PID:
LATITUDE: 29° 47.3' N ( 29.78753) LONGITUDE: 90° 24.9' W ( -90.41564)
The bench mark is a disk located along LA HWY 306, 89.61 m (294.00 ft) east of
bench mark 876 2482 H, 17.67 m (57.97 ft) NW of large split-trunk tree across
street from 3755 LA HWY 306, 11.27 m (36.97 ft) SSE of the SE corner of the
house at 3751 LA HWY 306, 7.62 m (25.00 ft) North of center of road, 1.21 m
(3.97 ft) NNE of the witness post, and 0.91 m (2.99 ft) north of light pole (no
number) in yard of 3751 LA HWY 306. The datum point is the top of a stainless
steel rod driven 27.40 m (89.89 ft) to refusal, in a sleeve extending to a depth
of 0.91 m (2.99 ft) and encased in a 5 -inch PVC pipe with an aluminum cover and
concrete kickblock. Note - sleeve depth does not meet the specifications for
class A rod mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 9
Station ID: 8762482 PUBLICATION DATE: 01/08/2021
Name: WEST BANK 1, BAYOU GAUCHE
LA
NOAA Chart: 11352 Latitude: 29° 47.3' N ( 29.78861)
USGS Quad: DES ALLEMANDS Longitude: 90° 25.2' W ( -90.42028)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2482 M 2016
DESIGNATION: 876 2482 M
MONUMENTATION: Flange-encased Rod VM#: 22330
AGENCY: NOS IDB PID:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 47.3' N ( 29.78750) LONGITUDE: 90° 24.9' W ( -90.41500)
The bench mark is located along LA HWY 306, 30.4 m (99.7 ft) NW of a 5 cm (2 in)
chlorinator regulator pipe sticking approximately 1 m (3.3 ft) above ground,
30.2 m (99.1 ft) east of telephone pole # P1013, 4.7 m (15.4 ft) north of
centerline of Bayou Gauche Rd, 15 cm (6 in) west of a witness post, and is a
stainless steel rod driven 27.1 m (88.8 ft) to substantial resistance, in a
sleeve extending to a depth of 1 m (3.3 ft) and encased in a 13 cm (5 in) PVC
pipe with an aluminum cover and concrete kick block.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 9
Station ID: 8762482 PUBLICATION DATE: 01/08/2021
Name: WEST BANK 1, BAYOU GAUCHE
LA
NOAA Chart: 11352 Latitude: 29° 47.3' N ( 29.78861)
USGS Quad: DES ALLEMANDS Longitude: 90° 25.2' W ( -90.42028)
T I D A L D A T U M S
Tidal datums at WEST BANK 1, BAYOU GAUCHE based on:
LENGTH OF SERIES: 9 YEARS
TIME PERIOD: June 2003 - August 2018
TIDAL EPOCH: 2012-2016
CONTROL TIDE STATION: 8761724 GRAND ISLE, EAST POINT
Elevations of tidal datums referred to Mean Sea Level (MSL), in METERS:
MEAN SEA LEVEL MSL = 0.000
North American Vertical Datum NAVD88 = -0.145
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MSL
2482 A 2003 0.247
2482 B 2003 0.345
2482 C 2003 0.308
2482 D 2003 1.448
2482 E 2003 1.217
2482 G 2006 0.322
2482 H 2006 0.478
2482 K 2006 0.147
2482 M 2016 0.267
Foot Notes:
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 9
Station ID: 8762482 PUBLICATION DATE: 01/08/2021
Name: WEST BANK 1, BAYOU GAUCHE
LA
NOAA Chart: 11352 Latitude: 29° 47.3' N ( 29.78861)
USGS Quad: DES ALLEMANDS Longitude: 90° 25.2' W ( -90.42028)
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.