U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
Station ID: 8762184 PUBLICATION DATE: 04/24/2018
Name: GOLDEN MEADOW, PLAISANCE CANAL
LA
NOAA Chart: 11352 Latitude: 29° 22.4' N ( 29.37330)
USGS Quad: BAY COURANT Longitude: 90° 15.9' W ( -90.26500)
To reach the tidal bench marks from the intersection of State Highways 1 and
3235, proceed south on State Highway 3235 to the Golden Meadow water tower on
the right, then turn right and proceed west past the hurricane protection wall
to Texaco Dock. The bench marks are on the Texaco Dock property and outside the
floodwall. The tide gage and staff were at the east end of a dock in front of a
valve shop on the north side of the Texaco slip.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 2184 A 1986
DESIGNATION: 876 2184 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 7234
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 22.4' N ( 29.37330) LONGITUDE: 90° 15.9' W ( -90.26500)
The primary bench mark is a disk located 28.83 m (94.6 ft) east of the SE corner
of a tin shed utilized as a valve shop, 12.74 m (41.8 ft) north of a freshwater
waterline on a small dock east of the valve shop, 12 m (39 ft) SW of the second
light pole west of a concrete platform supporting one large and two small tanks,
3.81 m (12.5 ft) NE of a 1-inch PVC water valve on the north side of the board
walkway between the valve shop and parking area, and 0.43 m (1.4 ft) south of a
witness post. The bench mark is set 6 cm (0.2 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.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 8762184 PUBLICATION DATE: 04/24/2018
Name: GOLDEN MEADOW, PLAISANCE CANAL
LA
NOAA Chart: 11352 Latitude: 29° 22.4' N ( 29.37330)
USGS Quad: BAY COURANT Longitude: 90° 15.9' W ( -90.26500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Y 220 1965
DESIGNATION: Y 220
MONUMENTATION: Bench Mark disk VM#: 7232
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AU1226
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 22.6' N ( 29.37670) LONGITUDE: 90° 15.6' W ( -90.26000)
The bench mark is a disk set in the top of a concrete monument 1.8 km (1.1 mi)
south of the Golden Meadow Post Office on the west side of State Highway 1, 16 m
(54 ft) east of the SE corner of the house at 2016 W. Lathrop (State Highway 1),
10 m (33 ft) west of the centerline of the highway, 3.41 m (11.2 ft) west of the
west edge of a sidewalk, 2.38 m (7.8 ft) north of a pipe fence post at the
corner of a steel mesh fence, 0.40 m (1.3 ft) east of a fence with a witness
sign attached, 0.3 m (1 ft) east of the fence, and level with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 8762184 PUBLICATION DATE: 04/24/2018
Name: GOLDEN MEADOW, PLAISANCE CANAL
LA
NOAA Chart: 11352 Latitude: 29° 22.4' N ( 29.37330)
USGS Quad: BAY COURANT Longitude: 90° 15.9' W ( -90.26500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Z 220 1965
DESIGNATION: Z 220
MONUMENTATION: Bench Mark disk VM#: 7233
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AU1229
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 29° 21.7' N ( 29.36170) LONGITUDE: 90° 15.3' W ( -90.25500)
The bench mark is a disk located 3.5 km (2.2 mi) SE of the Golden Meadow Post
Office on the SW side of State Highway 1 at a Lousiana Power and Light
substation, 24 m (79 ft) west of the centerline of the highway, 10.30 m (33.8
ft) north of the SE corner of the chain link fence surrounding the substation,
6.68 m (21.9 ft) south of the NE corner of the fence, 0.58 m (1.9 ft) east of
the fence, and 0.30 m (1.0 ft) NE of a witness post. The bench mark is set 0.61
m (2.0 ft) below the level of the highway, crimped to the top of a copper-clad
steel rod driven 31.7 m (104 ft), and encased in a 5-inch cast iron pipe.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 8762184 PUBLICATION DATE: 04/24/2018
Name: GOLDEN MEADOW, PLAISANCE CANAL
LA
NOAA Chart: 11352 Latitude: 29° 22.4' N ( 29.37330)
USGS Quad: BAY COURANT Longitude: 90° 15.9' W ( -90.26500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2184 B 1986
DESIGNATION: 876 2184 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 7235
AGENCY: National Ocean Service (NOS) IDB PID#: AU3526
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 22.4' N ( 29.37330) LONGITUDE: 90° 15.8' W ( -90.26330)
The bench mark is a disk located 64 m (210 ft) ENE of bench mark 2184 A 1986,
21.15 m (69.4 ft) NE of the NE corner of the concrete platform supporting one
large and two small tanks, 12.68 m (41.6 ft) NNW of a light pole with sign
Private Walk for the use of Texaco Employees, 10.76 m (35.3 ft) WSW of the
westernmost pile of a row of piles driven along the north side of the parking
area, and 0.37 m (1.2 ft) east of a witness post. The bench mark is set 6 cm
(0.2 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.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 8762184 PUBLICATION DATE: 04/24/2018
Name: GOLDEN MEADOW, PLAISANCE CANAL
LA
NOAA Chart: 11352 Latitude: 29° 22.4' N ( 29.37330)
USGS Quad: BAY COURANT Longitude: 90° 15.9' W ( -90.26500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2184 C 1986
DESIGNATION: 876 2184 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 7236
AGENCY: National Ocean Service (NOS) IDB PID#: AU3285
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 22.4' N ( 29.37330) LONGITUDE: 90° 15.8' W ( -90.26330)
The bench mark is a disk located 64 m (210 ft) ENE of bench mark 2184 B 1986,
29.26 m (96.0 ft) NNW of the NW corner of a loading crane west of the Texaco
office, 21.79 m (71.5 ft) NE of the NE corner of a metal loading ramp west of
the Texaco office, 9.60 m (31.5 ft) ESE of the south end of the westernmost
parking rail, 5.67 m (18.6 ft) SSW of a light pole in the parking area NW of the
Texaco office, and 0.37 m (1.2 ft) ESE of a witness post. The bench mark is set
at 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.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 8762184 PUBLICATION DATE: 04/24/2018
Name: GOLDEN MEADOW, PLAISANCE CANAL
LA
NOAA Chart: 11352 Latitude: 29° 22.4' N ( 29.37330)
USGS Quad: BAY COURANT Longitude: 90° 15.9' W ( -90.26500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2184 G 1987
DESIGNATION: 876 2184 G TIDAL
MONUMENTATION: Tidal Station disk VM#: 7238
AGENCY: National Ocean Service (NOS) IDB PID#: AU3524
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: AU3524
LATITUDE: 29° 22.4' N ( 29.37330) LONGITUDE: 90° 15.7' W ( -90.26170)
The bench mark is a disk located at the NE corner of the intersection of State
Highway 3235 and Lefort Lane, across the highway from the Golden Meadow water
tower, 12.19 m (40.0 ft) north of the centerline of Lefort Lane, 11.49 m (37.7
ft) east of the centerline of the northbound lane of State Highway 3235, 2.47 m
(8.1 ft) west of a red and green fire hydrant, and 0.64 m (2.1 ft) NW of a
concrete right-of-way post and witness post. The bench mark is set 9 cm (0.3
ft) below ground level, crimped to the top of a stainless steel rod driven 25.6
m (84 ft) to refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 8762184 PUBLICATION DATE: 04/24/2018
Name: GOLDEN MEADOW, PLAISANCE CANAL
LA
NOAA Chart: 11352 Latitude: 29° 22.4' N ( 29.37330)
USGS Quad: BAY COURANT Longitude: 90° 15.9' W ( -90.26500)
T I D A L D A T U M S
Tidal datums at GOLDEN MEADOW, PLAISANCE CANAL based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: November 1986 - October 1987
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 (03/24/1987) = 0.334
MEAN HIGHER HIGH WATER MHHW = 0.171
MEAN HIGH WATER MHW = 0.170
MEAN SEA LEVEL MSL = 0.092
MEAN TIDE LEVEL MTL = 0.086
MEAN LOW WATER MLW = 0.001
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (02/09/1987) = -0.629
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
2184 A 1986 0.234 0.064
Y 220 1965 0.111 -0.059
Z 220 1965 -0.074 -0.244
2184 B 1986 0.187 0.017
2184 C 1986 0.445 0.275
2184 G 1987 0.095 -0.075
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 8762184 PUBLICATION DATE: 04/24/2018
Name: GOLDEN MEADOW, PLAISANCE CANAL
LA
NOAA Chart: 11352 Latitude: 29° 22.4' N ( 29.37330)
USGS Quad: BAY COURANT Longitude: 90° 15.9' W ( -90.26500)
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.