U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 10
Station ID: 8762372 PUBLICATION DATE: 03/07/2018
Name: EAST BANK 1, NORCO, BAYOU LABRANCHE
LA
NOAA Chart: 11369 Latitude: 30° 3.0' N ( 30.05033)
USGS Quad: LABRANCHE Longitude: 90° 22.1' W ( -90.36800)
To reach the tidal bench marks from U.S. Highway I 10, proceed west on I 10 to
exit 220 (310 south), proceed on 310 south for 4.8 km (3.0 mi) to LA HWY 61 to
Norco, LA, go 10.6 km (6.6 mi) along LA 61 to the Bonnet Carre Spillway Road,
continue 5.5 km (3.4 mi) along Spillway Road to a steel gate with a lock,
proceed thru the gate turn right and proced to the Marsh Duck Hunt Club. The
bench marks are in the vicinity of the Marsh Duck Hunt Club and west along the
railroad and I-10 East. The tide gauge is located at the wooden pier on the
north side of the Hunt Club.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 2372 E 2003
DESIGNATION: 876 2372 E
MONUMENTATION: Flange-encased Rod VM#: 17089
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: DH3786
LATITUDE: 30° 3.0' N ( 30.05003) LONGITUDE: 90° 22.1' W ( -90.36786)
The primary bench mark is a flange-encased rod located 35.47 m (116.37 ft) east
from the ENE corner of the boat dock on the west side of the Hunt Club property,
9.27 m (30.41 ft) ENE from the NE corner of a storage shead, 6.90 m (22.64 ft)
WSW from the SW corner of a covered boat slip, and 0.30 m (0.98 ft) west of a
witness post. The datum point is the top of a stainless steel rod driven 30.5 m
(100.1 ft) to refusal, in a sleeve extending to a depth of 1.5 m (4.9 ft) and
encased in a 5-inch PVC pipe with an aluminum cover and concrete kickblock.
Note - sleeve depth does not meet specifications for a class A rod mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 10
Station ID: 8762372 PUBLICATION DATE: 03/07/2018
Name: EAST BANK 1, NORCO, BAYOU LABRANCHE
LA
NOAA Chart: 11369 Latitude: 30° 3.0' N ( 30.05033)
USGS Quad: LABRANCHE Longitude: 90° 22.1' W ( -90.36800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2372 F 2003
DESIGNATION: 876 2372 F TIDAL
MONUMENTATION: Flange-encased Rod VM#: 17090
AGENCY: National Ocean Service (NOS) IDB PID#: DH3787
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 30° 3.0' N ( 30.05064) LONGITUDE: 90° 22.1' W ( -90.36792)
The bench mark is a flange-encased rod located 54.0 m (177.2 ft) SSW from the
southern rail road track, 16.90 m (55.45 ft) NNE from the NE corner of the fish
cleaning station on the pier, 14.70 m (48.23 ft) NW of the NW corner of the
Marsh Duck Hunt Club building, 5.61 m (18.41 ft) SSW from the centerline of the
boat ramp on the west side of the Hunt Club, and 0.32 m (1.05 ft) north of the
witness post. The datum point is the top of a stainless steel rod driven 23.2 m
(76 ft) to refusal, in a sleeve extending to a depth of 1.5 m (4.9 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 a class A rod mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 10
Station ID: 8762372 PUBLICATION DATE: 03/07/2018
Name: EAST BANK 1, NORCO, BAYOU LABRANCHE
LA
NOAA Chart: 11369 Latitude: 30° 3.0' N ( 30.05033)
USGS Quad: LABRANCHE Longitude: 90° 22.1' W ( -90.36800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2372 G 2003
DESIGNATION: 876 2372 G
MONUMENTATION: Flange-encased Rod VM#: 17091
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless Steel Rod in Sleeve OPUS PID:
LATITUDE: 30° 3.0' N ( 30.05061) LONGITUDE: 90° 22.1' W ( -90.36764)
The bench mark is flange-encased rod located along the ILLINOIS center rail
road, 39.00 m (127.95 ft) SSW from the southern rail road track, 29.30 m (96.13
ft) south of the power pole with transformer at the NW side of the entrance
leading into the Marsh Duck Hunt Club, 18.20 m (59.71 ft) NNW from the NE corner
of the Marsh Duck Hunt Club, and 9.51 m (31.20 ft) WNW of the centerline of the
dirt drive leading into Marsh Duck Hunt Club. The datum point is the top of a
stainless steel rod driven 30.5 m (100.1 ft) to refusal, in a sleeve extending
to a depth of 1.5 m (4.92 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 a class A rod mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 10
Station ID: 8762372 PUBLICATION DATE: 03/07/2018
Name: EAST BANK 1, NORCO, BAYOU LABRANCHE
LA
NOAA Chart: 11369 Latitude: 30° 3.0' N ( 30.05033)
USGS Quad: LABRANCHE Longitude: 90° 22.1' W ( -90.36800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2372 H 2006
DESIGNATION: 876 2372 H
MONUMENTATION: Flange-encased Rod VM#: 18273
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 30° 3.1' N ( 30.05214) LONGITUDE: 90° 22.1' W ( -90.36889)
The bench mark is a flange encased rod located along the Illinois Central
Railroad, 224.20 m (735.56 ft) SW of utility pole number 657541, 101.20 m
(332.02 ft) NW of bench mark G 178, 46.33 m (152.00 ft) NW of a "W2" sign along
the railroad track, 15.54 m (50.98 ft) NNE of the centerline of the tracks, 6.40
m (21.00 ft) south of the high water mark of a nearby creek, and 0.91 m (2.99
ft) south of a witness post, and 0.31 m (1.02 ft) above the ground level. The
bench mark is the top of a stainless steel rod driven 27.40 m (89.9 ft) to
refusal resistance, in a sleeve extending to a depth of 0.91 m (2.98 ft) and
encased in a 5 - inch PVC pipe with an aluminum cover and concrete kickblock.
Note - Sleeve depth does not meet specifications for a class A rod mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 10
Station ID: 8762372 PUBLICATION DATE: 03/07/2018
Name: EAST BANK 1, NORCO, BAYOU LABRANCHE
LA
NOAA Chart: 11369 Latitude: 30° 3.0' N ( 30.05033)
USGS Quad: LABRANCHE Longitude: 90° 22.1' W ( -90.36800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2372 M 2006
DESIGNATION: 876 2372 M
MONUMENTATION: Flange-encased Rod VM#: 18274
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 30° 3.2' N ( 30.05300) LONGITUDE: 90° 22.2' W ( -90.37042)
The bench mark is a flange encased rod located along the Illinios Central
Railroad, 173.43 m (568.99 ft) WNW of bench mark 876 2372 H, 40.20 m (131.89 ft)
east of utility pole number 657541, 38.60 m (126.64 ft) SE of the SE corner of
the railroad control house, 15.46 m (50.72 ft) NE of the centerline of the
tracks, 3.66 m (12.01 ft) SE of the high water mark of the nearby creek, 2.74 m
(8.99 ft) east of a large 3-truncked tree, and 0.91 m (2.99 ft) SE of a witness
post, and 0.31 m (1.02 ft) above the ground level. The datum point is the top
of stainless steel rod driven 27.4 m (89.9 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 specifications
for a class A rod mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 10
Station ID: 8762372 PUBLICATION DATE: 03/07/2018
Name: EAST BANK 1, NORCO, BAYOU LABRANCHE
LA
NOAA Chart: 11369 Latitude: 30° 3.0' N ( 30.05033)
USGS Quad: LABRANCHE Longitude: 90° 22.1' W ( -90.36800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2372 J 2006
DESIGNATION: 876 2372 J
MONUMENTATION: Flange-encased Rod VM#: 18275
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 30° 3.2' N ( 30.05342) LONGITUDE: 90° 22.3' W ( -90.37101)
The bench mark is a flange-encased located along the Illinios Central Railroad,
67.05 m (219.98 ft) NW of bench mark 876 2372 I, 55.60 m (182.41 ft) NW of
utility pole number 657541, 39.20 m (128.61 ft) NW of the NW corner of railroad
control house, 36.90 m (121.06 ft) ENE of a fiber-optic warning pole, 31.00 m
(101.71 ft) east of a "railroad X-ing" sign, 3.35 m (10.99 ft) SE of the SE face
of a concrete foundation block, 2.90 m (9.51 ft) ENE of a group of multi-trunked
trees, and 0.31 m (1.02 ft) above the ground level. The bench mark is the top
of a stainless steel rod driven 27.4 m (89.9 ft) to refusal resistance, in a
sleeve extending to a depth of 0.91 m (2.99 ft) and encased in a 5 - inch PVC
pipe with aluminum cover and concrete kickblock. Note - sleeve depth does not
meet specifications for a class A rod mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 10
Station ID: 8762372 PUBLICATION DATE: 03/07/2018
Name: EAST BANK 1, NORCO, BAYOU LABRANCHE
LA
NOAA Chart: 11369 Latitude: 30° 3.0' N ( 30.05033)
USGS Quad: LABRANCHE Longitude: 90° 22.1' W ( -90.36800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2372 L 2006
DESIGNATION: 876 2372 L
MONUMENTATION: Flange-encased Rod VM#: 18277
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 30° 0.3' N ( 30.00531) LONGITUDE: 90° 22.3' W ( -90.37233)
The bench mark is a flange-encased rod located 94.49 m (310.01 ft) NE of the
northernmost leg of the railroad bridge support structure in the center of the
road, 68.28 m (224.015 ft) NW of bench mark 876 2372 K, 53.04 m (174.02 ft)
SSW of south corner of boatramp, 14.33 m (47.01 ft) SW of utility pole with
attached meter with NO number, 9.45 m (31.00 ft) NW of center of road, 1.52 m
(4.99 ft) NW of a utility pole with NO number, and 0.31 m (1.02 ft) above the
ground level. The datum point is the top of a stainless steel rod driven 27.4 m
(89.9 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 specifications for a class A rod mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 10
Station ID: 8762372 PUBLICATION DATE: 03/07/2018
Name: EAST BANK 1, NORCO, BAYOU LABRANCHE
LA
NOAA Chart: 11369 Latitude: 30° 3.0' N ( 30.05033)
USGS Quad: LABRANCHE Longitude: 90° 22.1' W ( -90.36800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Z 274 1969
DESIGNATION: Z 274
MONUMENTATION: Bench Mark disk VM#: 18278
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: BJ1478
SETTING CLASSIFICATION: Concrete pile supporting OPUS PID:
LATITUDE: 30° 3.3' N ( 30.05522) LONGITUDE: 90° 22.3' W ( -90.37183)
The bench mark is a disk set in a support concrete pile of the I-10 freeway,
located 49.38 m (162.0 ft) east of bench mark 876 2372 L, 36.27 m (119.00 ft) NW
of nearby freeway leg that rests in standing water, 25.60 m (83.99 ft) north of
utility pole number 5-55, 21.95 m (72.01 ft) SE of the road at the top of the
Levy, and 1.52 m (4.99 ft) above the ground level.
BENCH MARK STAMPING: 381 1986
DESIGNATION: 381 1986
MONUMENTATION: Flange-encased Rod VM#: 18279
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Steel rod OPUS PID:
LATITUDE: 30° 3.3' N ( 30.05442) LONGITUDE: 90° 22.4' W ( -90.37261)
The bench mark is a flange-encased rod located 188.97 m (619.98 ft) NW of bench
mark 876 2372 J, 21.03 m (69.00 ft) SW of the largest and southwesternmost tree
of the nearby copse, 18.29 m (60.01 ft) SE of the road at the top of the Levy,
5.49 m (18.01 ft) NW of a utility pole with NO number, and 3.35 m (10.99 ft)
NNW of a survey marker. The datum point is the top of a stainless steel rod
driven into the the ground to an unknown depth and encased in a 5 -inch PVC pipe
with aluminum cover and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 10
Station ID: 8762372 PUBLICATION DATE: 03/07/2018
Name: EAST BANK 1, NORCO, BAYOU LABRANCHE
LA
NOAA Chart: 11369 Latitude: 30° 3.0' N ( 30.05033)
USGS Quad: LABRANCHE Longitude: 90° 22.1' W ( -90.36800)
T I D A L D A T U M S
Tidal datums at EAST BANK 1, NORCO, BAYOU LABRANCHE based on:
LENGTH OF SERIES: 3 YEARS
TIME PERIOD: 11/03-10/04, 5/07-4/08, 9/10-8/11
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 (08/30/2005) = 1.654
MEAN HIGHER HIGH WATER MHHW = 0.140
MEAN HIGH WATER MHW = 0.139
MEAN SEA LEVEL MSL = 0.077
MEAN TIDE LEVEL MTL = 0.070
MEAN LOW WATER MLW = 0.001
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (12/14/2010) = -0.704
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
2372 E 2003 0.090 -0.049
2372 F 2003 0.351 0.212
2372 G 2003 0.201 0.062
2372 H 2006 1.078 0.939
2372 M 2006 0.780 0.641
2372 J 2006 0.848 0.709
2372 L 2006 0.456 0.317
Z 274 1969 1.948 1.809
381 1986 1.348 1.209
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 10 of 10
Station ID: 8762372 PUBLICATION DATE: 03/07/2018
Name: EAST BANK 1, NORCO, BAYOU LABRANCHE
LA
NOAA Chart: 11369 Latitude: 30° 3.0' N ( 30.05033)
USGS Quad: LABRANCHE Longitude: 90° 22.1' W ( -90.36800)
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.