U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8760889 PUBLICATION DATE: 04/13/2018
Name: OLGA COMPRESSOR STATION, GRAND BAY
LA
NOAA Chart: 11364 Latitude: 29° 23.2' N ( 29.38656)
USGS Quad: COQUILLE POINT Longitude: 89° 22.8' W ( -89.38014)
To reach the tidal bench marks from Venice, LA, proceed by boat from The Jump
1.9 km (1.0 nm) north upstream on the Mississippi River to the first channel on
the right leading to Baptiste Collette Bayou, turn right and proceed 9.0 km (4.8
nm) NE through Baptiste Collette Bayou and Main Pass to a dredged east-west
canal near the end of Main Pass, then turn left and proceed west for 2.9 km (1.6
nm) and exit the canal, and proceed NW across Grand Bay for 6.1 km (3.3 nm) to
Olga Compressor Station. The bench marks are located on the platforms
throughout the station. The tide gauges were located at the eastern most corner
of the communication tower platform, the platform closest to and with stairs
down to the crew boat dock. The tide staff was on a pile just NW of the tide
gauges.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 0889 J 2008
DESIGNATION: 876 0889 J
MONUMENTATION: Tidal Station disk VM#: 19114
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Elevated concrete platform OPUS PID:
LATITUDE: 29° 23.2' N ( 29.38644) LONGITUDE: 89° 22.8' W ( -89.37961)
The primary bench mark is a disk set flush in the northern corner along the NW
edge of the largest platform (former compressor platform), 23.03 m (75.6 ft) NW
of SE outside face of platform, 6.15 m (20.2 ft) SW of NE outside face of
platform, and 0.52 m (1.7 ft) SE of NW outside face of platform.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8760889 PUBLICATION DATE: 04/13/2018
Name: OLGA COMPRESSOR STATION, GRAND BAY
LA
NOAA Chart: 11364 Latitude: 29° 23.2' N ( 29.38656)
USGS Quad: COQUILLE POINT Longitude: 89° 22.8' W ( -89.38014)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0889 F 2008
DESIGNATION: 876 0889 F
MONUMENTATION: Tidal Station disk VM#: 19115
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Elevated concrete platform OPUS PID:
LATITUDE: 29° 23.1' N ( 29.38561) LONGITUDE: 89° 22.8' W ( -89.38067)
The bench mark is a disk set flush in concrete near the east edge of the most SW
platform (Discharge Platform), 7.90 m (25.9 ft) north of the southern outside
face of platform, 6.77 m (22.2 ft) south of the north outside face of platform,
0.38 m (1.2 ft) west of the east outside face of platform, and 0.20 m (0.7 ft)
west of centerline of curb on eastern edge of platform.
BENCH MARK STAMPING: 0889 G 2008
DESIGNATION: 876 0889 G
MONUMENTATION: Tidal Station disk VM#: 19116
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Elevated concrete platform OPUS PID:
LATITUDE: 29° 23.1' N ( 29.38572) LONGITUDE: 89° 22.8' W ( -89.37939)
The bench mark is a disk set flush in the top of the curb on the northern edge
of the most western of two adjacent platforms at SE end of facility (receiving
platforms), 12.29 m (40.3 ft) west of the eastern outside face of platform, 9.07
m (29.8 ft) north of the southern outside face of platform, 1.36 m (4.5 ft) east
of the western outside face of platform, and 0.22 m (0.7 ft) above deck of
platform.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8760889 PUBLICATION DATE: 04/13/2018
Name: OLGA COMPRESSOR STATION, GRAND BAY
LA
NOAA Chart: 11364 Latitude: 29° 23.2' N ( 29.38656)
USGS Quad: COQUILLE POINT Longitude: 89° 22.8' W ( -89.38014)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0889 H 2008
DESIGNATION: 876 0889 H
MONUMENTATION: Tidal Station disk VM#: 19117
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Elevated concrete platform OPUS PID#: BBBG69
LATITUDE: 29° 23.2' N ( 29.38614) LONGITUDE: 89° 22.8' W ( -89.37975)
The bench mark is a disk set flush in concrete on the SE edge of the largest
platform (former compressor platform), 22.12 m (72.6 ft) SE of the centerline of
the SE end of the walkway to the communication tower platform, 9.02 m (29.6 ft)
NE of the SW outside edge of platform, and 0.33 m (1.08 ft) NW of the SE outside
edge of platform.
BENCH MARK STAMPING: 0889 K 2008
DESIGNATION: 876 0889 K
MONUMENTATION: Tidal Station disk VM#: 19118
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Elevated concrete platform OPUS PID:
LATITUDE: 29° 23.2' N ( 29.38656) LONGITUDE: 89° 22.8' W ( -89.38017)
The bench mark is set above the surface of the concrete deck and faired with
cement along the SE side of the communication tower platform, 4.50 m (14.8 ft)
east of the center of the communication tower, 0.90 m (3.0 ft) NNE from the
center of an access gate at the top of a steel stairway, and 0.17 m (0.6 ft) NW
of the concrete curb along the SE side of the platform.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8760889 PUBLICATION DATE: 04/13/2018
Name: OLGA COMPRESSOR STATION, GRAND BAY
LA
NOAA Chart: 11364 Latitude: 29° 23.2' N ( 29.38656)
USGS Quad: COQUILLE POINT Longitude: 89° 22.8' W ( -89.38014)
T I D A L D A T U M S
Tidal datums at OLGA COMPRESSOR STATION, GRAND BAY based on:
LENGTH OF SERIES: 6 MONTHS
TIME PERIOD: 6/08 - 8/08, 10/08, 12/08 - 1/09
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:
MEAN HIGHER HIGH WATER MHHW = 0.391
MEAN HIGH WATER MHW = 0.387
MEAN SEA LEVEL MSL = 0.204
MEAN TIDE LEVEL MTL = 0.198
MEAN LOW WATER MLW = 0.009
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
0889 J 2008 4.398 4.011
0889 F 2008 2.627 2.240
0889 G 2008 2.888 2.501
0889 H 2008 4.433 4.046
0889 K 2008 4.517 4.130
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8760889 PUBLICATION DATE: 04/13/2018
Name: OLGA COMPRESSOR STATION, GRAND BAY
LA
NOAA Chart: 11364 Latitude: 29° 23.2' N ( 29.38656)
USGS Quad: COQUILLE POINT Longitude: 89° 22.8' W ( -89.38014)
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.