U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 8762231 PUBLICATION DATE: 04/13/2018
Name: SALVADOR WMA, LAKE SALVADOR
LA
NOAA Chart: 11352 Latitude: 29° 46.3' N ( 29.77170)
USGS Quad: LAKE CATAOUATCHE WEST Longitude: 90° 17.4' W ( -90.29000)
To reach the tidal bench marks from Pier 90 Marina at U.S. Highway 90 and Bayou
Verret, proceed by boat south through Bayou Verret, across Lake Cataouatche and
through Bayou Couba, turn right into Bayou Couba Oil Field Canal at the entrance
to Lake Salvador and go west in the canal to the third dredged canal on the
left, turn left into the canal and go south to the second slip on the left, turn
left to Salvador Wildlife Management Area (W.M.A.) Headquarters on the right.
The bench marks are in the vicinity of the W.M.A. camp complex. The tide gage
and staff were located on the west end of the wharf that is on the north side of
the camp complex.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 2231 A 1985
DESIGNATION: 876 2231 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 7246
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 46.3' N ( 29.77170) LONGITUDE: 90° 17.4' W ( -90.29000)
The primary bench mark is a disk located near the west end of the camp complex,
at the north edge of the marsh that lies to the south of the complex, 23.56 m
(77.3 ft) SSW of the NE corner pile supporting the west living quarters, 5.88 m
(19.3 ft) SW of the SW corner of the water tank platform behind the west living
quarters, and 0.46 m (1.5 ft) north of a 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 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 7
Station ID: 8762231 PUBLICATION DATE: 04/13/2018
Name: SALVADOR WMA, LAKE SALVADOR
LA
NOAA Chart: 11352 Latitude: 29° 46.3' N ( 29.77170)
USGS Quad: LAKE CATAOUATCHE WEST Longitude: 90° 17.4' W ( -90.29000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: COUBA 1972
DESIGNATION: COUBA
MONUMENTATION: Triangulation Station disk VM#: 7245
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AU2876
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 46.3' N ( 29.77170) LONGITUDE: 90° 17.4' W ( -90.29000)
The bench mark is a disk set in the top of a 0.3 m (1 ft) diameter concrete
monument near the center of the camp complex, 87.69 m (287.7 ft) SW of bench
mark 2231 C 1985, 7.96 m (26.1 ft) north of the south side of a wooden bulkhead,
7.96 m (26.1 ft) SSW of the face of the NW corner pile of a storage shed, 6.89 m
(22.6 ft) east of the SE corner of the workshop building, 5.61 m (18.4 ft) WNW
of the face of the SW corner pile of the storage shed, and 0.15 m (0.5 ft) below
ground level.
BENCH MARK STAMPING: 2231 B 1985
DESIGNATION: 876 2231 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 7247
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 46.3' N ( 29.77170) LONGITUDE: 90° 17.4' W ( -90.29000)
The bench mark is a disk located near the center of the camp complex, 67.06 m
(220.0 ft) east of bench mark 2231 A 1985, 16.76 m (55.0 ft) SW of the SW corner
of the east living quarters, 14.66 m (48.1 ft) WNW of the NW corner of the tool
shed, 7.32 m (24.0 ft) NE of the NE corner of the generator shed, and 0.37 m
(1.2 ft) north of a 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 20.7 m (68 ft)
to refusal, 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 3 of 7
Station ID: 8762231 PUBLICATION DATE: 04/13/2018
Name: SALVADOR WMA, LAKE SALVADOR
LA
NOAA Chart: 11352 Latitude: 29° 46.3' N ( 29.77170)
USGS Quad: LAKE CATAOUATCHE WEST Longitude: 90° 17.4' W ( -90.29000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2231 C 1985
DESIGNATION: 876 2231 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 7248
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 46.3' N ( 29.77170) LONGITUDE: 90° 17.4' W ( -90.29000)
The bench mark is a disk located near the NE corner of the camp complex, 70.04 m
(229.8 ft) ENE of bench mark 2231 B 1985, 32.31 m (106.0 ft) east of the SE
corner of the water tank platform near the east living quarters, 21.52 m (70.6
ft) NNE of the NW corner pile supporting the covered storage area, 9.14 m (30.0
ft) west of the northernmost cypress tree near the east end of the complex, and
0.30 m (1.0 ft) north of a 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 24.4 m
(80 ft) to substantial resistance, and encased in a 5-inch PVC pipe and concrete
kickblock.
BENCH MARK STAMPING: 2231 D 1985
DESIGNATION: 876 2231 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 7249
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 46.3' N ( 29.77170) LONGITUDE: 90° 17.4' W ( -90.29000)
The bench mark is a disk located near the SE corner of the camp complex, on the
south side of the rear slip, 103.45 m (339.4 ft) south of bench mark 2231 C
1985, 10.67 m (35.0 ft) ENE of the south end of a large log on the south bank of
the rear slip, 7.13 m (23.4 ft) south of the south bank of the rear slip, and
0.61 m (2.0 ft) north of a witness post. The bench mark is set at ground level,
crimped to the top of a stainless steel rod driven 19.5 m (64 ft) to refusal,
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 4 of 7
Station ID: 8762231 PUBLICATION DATE: 04/13/2018
Name: SALVADOR WMA, LAKE SALVADOR
LA
NOAA Chart: 11352 Latitude: 29° 46.3' N ( 29.77170)
USGS Quad: LAKE CATAOUATCHE WEST Longitude: 90° 17.4' W ( -90.29000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2231 E 1985
DESIGNATION: 876 2231 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 7250
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 46.3' N ( 29.77170) LONGITUDE: 90° 17.4' W ( -90.29000)
The bench mark is a disk located near the SW corner of the camp complex, on the
south side of the rear slip, 66.93 m (219.6 ft) WSW of bench mark 2231 D 1985,
8.38 m (27.5 ft) SSW of the west end of an 8-inch iron pipe lying on the bank of
the slip, 8.14 m (26.7 ft) SSE of the SW corner of a permanent tin shed, and
0.46 m (1.5 ft) north of a witness post. The bench mark is set at ground level,
crimped to the top of a stainless steel rod driven 20.7 m (68 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 7
Station ID: 8762231 PUBLICATION DATE: 04/13/2018
Name: SALVADOR WMA, LAKE SALVADOR
LA
NOAA Chart: 11352 Latitude: 29° 46.3' N ( 29.77170)
USGS Quad: LAKE CATAOUATCHE WEST Longitude: 90° 17.4' W ( -90.29000)
T I D A L D A T U M S
Tidal datums at SALVADOR WMA, LAKE SALVADOR based on:
LENGTH OF SERIES: 8 MONTHS
TIME PERIOD: 10/85 - 12/85, 4/86 - 6/86, 8/86 - 9/86
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)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MSL
2231 A 1985 -0.112
COUBA 1972 -0.056
2231 B 1985 -0.047
2231 C 1985 0.196
2231 D 1985 0.202
2231 E 1985 -0.164
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8762231 PUBLICATION DATE: 04/13/2018
Name: SALVADOR WMA, LAKE SALVADOR
LA
NOAA Chart: 11352 Latitude: 29° 46.3' N ( 29.77170)
USGS Quad: LAKE CATAOUATCHE WEST Longitude: 90° 17.4' W ( -90.29000)
Foot Notes:
Bench mark COUBA 1972 is based on one differential leveling connection and does
not meet the quality control standards of the NOS. Therefore, caution should be
used when deriving elevations for this mark.
This station has been determined to be Non-tidal for tidal datum purposes.
There is either no measureable periodic rise and fall of the tide at this
location, or it may be present but inconsistent, or the periodic tide is present
and consistent, however the Mean Range of Tide (MN) is negligible, that is below
the established tidal/non-tidal threshold of 0.03m (0.10ft). Only the datum of
local Mean Sea Level (MSL) is published at these stations. For Nautical
Charting Datum applications, a non-tidal Low Water Datum (LWD) is established as
0.50ft (0.15m) below MSL.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8762231 PUBLICATION DATE: 04/13/2018
Name: SALVADOR WMA, LAKE SALVADOR
LA
NOAA Chart: 11352 Latitude: 29° 46.3' N ( 29.77170)
USGS Quad: LAKE CATAOUATCHE WEST Longitude: 90° 17.4' W ( -90.29000)
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.