U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
Station ID: 8765171 PUBLICATION DATE: 09/22/2009
Name: NEW IBERIA DRAINAGE CANAL
LA
NOAA Chart: 11349 Latitude: 29° 56.9' N ( 29.94830)
USGS Quad: NEW IBERIA SOUTH Longitude: 91° 50.3' W ( -91.83830)
To reach the tidal bench marks from the intersection of US Highway 90 and State
Road 83 in New Iberia, proceed south on State Road 83 (Weeks Island Road) for
1.3 km (0.8 mi), then turn right and continue west on Port Road for 1.3 km (0.8
mi), then left on S. Lewis Street for 0.3 km (0.2 mi) to the Port of Iberia. The
bench marks are located along S. Lewis Street. The tide gauge was located on the
south side of the canal at the port.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 5171 A 2001
DESIGNATION: 876 5171 A
MONUMENTATION: Tidal Station disk VM#: 16559
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Light pole base OPUS PID:
LATITUDE: 29° 56.7' N ( 29.94500) LONGITUDE: 91° 50.3' W ( -91.83830)
The primary bench mark is set flush in the SE corner of the foundation of a
light pole in the NW corner of the property of the Port of Iberia, 24.24 m (79.5
ft) north of the NW corner of the Port of Iberia office building, 21.37 m (70.1
ft) west of the SE corner of a small brick building in the NE corner of the Port
of Iberia property, 12.57 m (41.2 ft) south of the centerline of Lewis Street,
and 1.52 m (5.0 ft) SW of a witness post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
Station ID: 8765171 PUBLICATION DATE: 09/22/2009
Name: NEW IBERIA DRAINAGE CANAL
LA
NOAA Chart: 11349 Latitude: 29° 56.9' N ( 29.94830)
USGS Quad: NEW IBERIA SOUTH Longitude: 91° 50.3' W ( -91.83830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5171 B 2001
DESIGNATION: 876 5171 B
MONUMENTATION: Tidal Station disk VM#: 16560
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Sign foundation OPUS PID:
LATITUDE: 29° 56.8' N ( 29.94670) LONGITUDE: 91° 50.2' W ( -91.83670)
The bench mark is set flush in a large concrete pad and sign foundation for the
Unifab sign, 63.44 m (208.1 ft) north of the NW corner of a red block building,
15.01 m (49.2 ft) WSW of the centerline of Lewis Street, 3.05 m (10.0 ft) SW of
a witness post, 1.32 m (4.3 ft) ESE of the west leg of the Unifab sign, and 1.22
m (4.00 ft) SW of the east leg of the Unifab sign.
BENCH MARK STAMPING: 5171 C 2001
DESIGNATION: 876 5171 C
MONUMENTATION: Tidal Station disk VM#: 16561
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Small bridge OPUS PID#: BBBX72
LATITUDE: 29° 56.9' N ( 29.94830) LONGITUDE: 91° 50.2' W ( -91.83670)
The bench mark is set flush on top of a small concrete bridge at the second
pier, 81.63 m (267.8 ft) west of the intersection of Port Road and Lewis Street,
25.89 m (84.9 ft) east of the west end of the bridge, and 3.61 m (11.8 ft) south
of the centerline of Port Road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
Station ID: 8765171 PUBLICATION DATE: 09/22/2009
Name: NEW IBERIA DRAINAGE CANAL
LA
NOAA Chart: 11349 Latitude: 29° 56.9' N ( 29.94830)
USGS Quad: NEW IBERIA SOUTH Longitude: 91° 50.3' W ( -91.83830)
T I D A L D A T U M S
Tidal datums at NEW IBERIA DRAINAGE CANAL based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: August 2001 - September 2001
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8771510 GALVESTON PLEASURE PIER, GULF OF MEXICO
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.588
MEAN HIGH WATER MHW = 0.560
MEAN SEA LEVEL MSL = 0.329
MEAN TIDE LEVEL MTL = 0.322
MEAN LOW WATER MLW = 0.084
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
5171 A 2001 2.049 1.489
5171 B 2001 1.737 1.177
5171 C 2001 2.214 1.654
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
Station ID: 8765171 PUBLICATION DATE: 09/22/2009
Name: NEW IBERIA DRAINAGE CANAL
LA
NOAA Chart: 11349 Latitude: 29° 56.9' N ( 29.94830)
USGS Quad: NEW IBERIA SOUTH Longitude: 91° 50.3' W ( -91.83830)
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.