U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8761294 PUBLICATION DATE: 04/23/2010
Name: WEST PEARL RIVER
LA
NOAA Chart: 11371 Latitude: 30° 13.8' N ( 30.23000)
USGS Quad: RIGOLETS Longitude: 89° 40.1' W ( -89.66830)
To reach the tidal bench marks from the NE end of the U.S. Highway 90 bridge
over the Rigolets, proceed NE on U.S. Highway 90 for 8.4 km (5.2 mi) to the west
end of the bridge over the West Pearl River. The bench marks are located along
the highway west of the bridge. The tide gage and staff were located on a small
pier at the SW corner of the bridge, next to the bridge tender's house.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1294 A 1980
DESIGNATION: 876 1294 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 15781
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 13.8' N ( 30.23000) LONGITUDE: 89° 40.1' W ( -89.66830)
The primary bench mark is a disk located near the SW corner of the U.S. Highway
90 bridge over the West Pearl River, 49 m (162 ft) west of the east end of the
boat landing dock, 19 m (63 ft) south of the centerline of U.S. Highway 90, 16 m
(52 ft) SSE of the SW end of the bridge, 11 m (36 ft) east of the NE corner of
the bridge tender's residence, 10 m (34 ft) NNE of a 0.85 m (2.8 ft) DBH oak
tree, and 1.13 m (3.7 ft) SE of a three trunk black locust tree. The bench mark
is set 9 cm (0.3 ft) below ground level, crimped to the top of a stainless steel
rod, driven 14.0 m (46 ft) to refusal 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 2 of 6
Station ID: 8761294 PUBLICATION DATE: 04/23/2010
Name: WEST PEARL RIVER
LA
NOAA Chart: 11371 Latitude: 30° 13.8' N ( 30.23000)
USGS Quad: RIGOLETS Longitude: 89° 40.1' W ( -89.66830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1294 B 1980
DESIGNATION: 876 1294 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 15782
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 13.8' N ( 30.23000) LONGITUDE: 89° 40.1' W ( -89.66830)
The bench mark is a disk located near the bridge tender's house, 80 m (263 ft)
WSW of bench mark 141, 61 m (201 ft) WSW of the SW end of the U.S. Highway 90
bridge over the Pearl River, 43 m (140 ft) west of the west wall of the bridge
tender's house, and 30 m (97 ft) south of the centerline of U.S. Highway 90.
The bench mark is set 9 cm (0.3 ft) below ground level, crimped to the top of a
stainless steel rod driven 14.3 m (47 ft) to refusal and encased in a 4-inch PVC
pipe and concrete kickblock.
BENCH MARK STAMPING: 1294 C 1980
DESIGNATION: 876 1294 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 15783
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 13.8' N ( 30.23000) LONGITUDE: 89° 40.1' W ( -89.66830)
The bench mark is a disk located 115 m (376 ft) WNW of the NW end of the U.S.
Highway 90 bridge over the West Pearl River, 75 m (247 ft) NW of bench mark 1294
B 1980, 64 m (211 ft) NE of a power pole on the south side of U.S. Highway 90,
and on the west side of a shell road leading south from the highway to an oil
well site, and 15 m (49 ft) north of the centerline of U.S. Highway 90. The
bench mark is set 9 cm (0.3 ft) below ground level, crimped to the top of a
stainless steel rod, driven 15.8 m (52 ft) 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
Station ID: 8761294 PUBLICATION DATE: 04/23/2010
Name: WEST PEARL RIVER
LA
NOAA Chart: 11371 Latitude: 30° 13.8' N ( 30.23000)
USGS Quad: RIGOLETS Longitude: 89° 40.1' W ( -89.66830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 141
DESIGNATION: 141
MONUMENTATION: Survey disk VM#: 15784
AGENCY: Louisiana Geodetic Survey (LAGS) IDB PID#: BH1219
SETTING CLASSIFICATION: Curb OPUS PID:
LATITUDE: 30° 13.9' N ( 30.23170) LONGITUDE: 89° 40.1' W ( -89.66830)
The bench mark is a disk set flush in the top of the curb on the north side of
the westbound lane of the U.S. Highway 90 bridge over the West Pearl River, 70 m
(229 ft) west of the center of the draw bridge span, 32 m (105 ft) NE of the
center of the front porch door of the bridge tender's residence, 17.31 m (56.8
ft) east of the west end of the bridge, and 3.68 m (12.1 ft) north of the
centerline of the highway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8761294 PUBLICATION DATE: 04/23/2010
Name: WEST PEARL RIVER
LA
NOAA Chart: 11371 Latitude: 30° 13.8' N ( 30.23000)
USGS Quad: RIGOLETS Longitude: 89° 40.1' W ( -89.66830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Q 92 1938
DESIGNATION: Q 92
MONUMENTATION: Bench Mark disk VM#: 15785
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: BH1220
SETTING CLASSIFICATION: Concrete post OPUS PID:
LATITUDE: 30° 13.9' N ( 30.23170) LONGITUDE: 89° 40.6' W ( -89.67670)
The bench mark is a disk set flush in a concrete post projecting 0.21 m (0.7 ft)
above ground level, 91 m (300 ft) ENE of the centerline intersection of U.S.
Highways 90 and 190 W, 19.51 m (64.0 ft) north of the centrerline of Highway 90,
12 m (39 ft) west of the west end of a drainage pond, 11 m (36 ft) NW of a power
pole, 5 m (15 ft) east of the centerline of a shell road leading to a "Rest
Area", 3.51 m (11.5 ft) WSW of an 0.46 m (1.5 ft) DBH pine tree, and 0.30 m (1
ft) north of a witness post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8761294 PUBLICATION DATE: 04/23/2010
Name: WEST PEARL RIVER
LA
NOAA Chart: 11371 Latitude: 30° 13.8' N ( 30.23000)
USGS Quad: RIGOLETS Longitude: 89° 40.1' W ( -89.66830)
T I D A L D A T U M S
Tidal datums at WEST PEARL RIVER based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: January 1981 - December 1981
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8747437 BAY WAVELAND YACHT CLUB, BAY ST. LOUIS
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (05/05/1981) = 0.444
MEAN HIGHER HIGH WATER MHHW = 0.189
MEAN HIGH WATER MHW = 0.187
MEAN SEA LEVEL MSL = 0.102
MEAN TIDE LEVEL MTL = 0.094
MEAN LOW WATER MLW = 0.001
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (10/19/1981) = -0.388
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1294 A 1980 1.600 1.413
1294 B 1980 1.649 1.462
1294 C 1980 1.945 1.758
141 4.028 3.841
Q 92 1938 2.253 2.066
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8761294 PUBLICATION DATE: 04/23/2010
Name: WEST PEARL RIVER
LA
NOAA Chart: 11371 Latitude: 30° 13.8' N ( 30.23000)
USGS Quad: RIGOLETS Longitude: 89° 40.1' W ( -89.66830)
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.