U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8764044 PUBLICATION DATE: 05/19/2020
Name: BERWICK, ATCHAFALAYA RIVER, LA
LA
NOAA Chart: 11355 Latitude: 29° 40.1' N ( 29.66750)
USGS Quad: MORGAN CITY Longitude: 91° 14.3' W ( -91.23761)
To reach the tidal bench marks from Berwick, proceed west on US Highway 90 for
1.3 km (0.8 mi) to the intersection of Parish Road 27 and Berwick Road South,
turn left (south) on Road 27 and continue 1.6 km (1.0 mi) to the intersection
with River Road, then turn right on River Road and continue for 0.8 km (0.5 mi)
to the intersection with Spirit Lane and the Star Enterprises Marine Terminal.
The bench marks are located on the terminal property and along River Road.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4044 E 2003
DESIGNATION: 876 4044 E
MONUMENTATION: Flange-encased Rod VM#: 17167
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBBB76
LATITUDE: 29° 40.0' N ( 29.66697) LONGITUDE: 91° 14.4' W ( -91.23997)
The primary bench mark is a flanged-encased rod located in a grassy area between
River Road and a small canal, located 10.56 m (34.6 ft) SE of the canals edge,
9.35 m (30.68 ft ) west of the centerline of River road, 2.75 m (9.02 ft) south
of the center of a power pole with guy wire, 2.64 m (8.7 ft) NW of a manhole
cover and 1.0 m ( 3.28 ft ) east of a witness post. The datum point is the top
of the stainless steel rod driven 33.80 m (110.89 ft) to refusal and encased in
a 5-inch NOS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8764044 PUBLICATION DATE: 05/19/2020
Name: BERWICK, ATCHAFALAYA RIVER, LA
LA
NOAA Chart: 11355 Latitude: 29° 40.1' N ( 29.66750)
USGS Quad: MORGAN CITY Longitude: 91° 14.3' W ( -91.23761)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4044 C 2003
DESIGNATION: 876 4044 C
MONUMENTATION: Flange-encased Rod VM#: 17336
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBFX57
LATITUDE: 29° 40.7' N ( 29.67797) LONGITUDE: 91° 14.4' W ( -91.23922)
The bench mark is a flange-encased rod located 12.00 m (39.37 ft ) SE of the
centerline of River Road, 9.51 m (31.20 ft ) NE of a fire hydrant, 6.75 m (22.15
ft) north of a power pole numbered 02990-36409, power pole has a transformer and
light attached, 6.51 m (21.36 ft) south of spirit lane and 1.0 m (3.28 ft) west
of a witness post. The datum point is set 10 cm (0.3 ft) below grade, being the
top of the stainless steel rod driven 28.6 m (93.8 ft) to refusal, and encased
in a 5-inch NOS logo cap.
BENCH MARK STAMPING: 4044 D 2003
DESIGNATION: 876 4044 D
MONUMENTATION: Flange-encased Rod VM#: 17337
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBFX58
LATITUDE: 29° 39.9' N ( 29.66553) LONGITUDE: 91° 14.5' W ( -91.24089)
The bench mark is a flange-encased rod located in a grassy area between River
Road and a canal, 25.26 m (82.9 ft) south of the bigger of two concrete and
metal manhole covers, 11.25 m (36.91 ft) west of the centerline of River Road,
10.50 m (34.449 ft) east of the west bank of a canal that leads to the
Achafalaya River, 2.85 m (9.35 ft) SW of a power pole with a transformer, and
0.90 m (2.95 ft) east of a witness post. The datum point is 12 cm (0.40 ft)
below grade, being the top of a stainless steel rod driven 27.8 m (91.2 ft) to
refusal, and encased in a 5-inch NOS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8764044 PUBLICATION DATE: 05/19/2020
Name: BERWICK, ATCHAFALAYA RIVER, LA
LA
NOAA Chart: 11355 Latitude: 29° 40.1' N ( 29.66750)
USGS Quad: MORGAN CITY Longitude: 91° 14.3' W ( -91.23761)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4044 H 2015
DESIGNATION: 876 4044 H
MONUMENTATION: Flange-encased Rod VM#: 21595
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 29° 39.8' N ( 29.66414) LONGITUDE: 91° 14.5' W ( -91.24178)
The bench mark is a flange-encased rod located 30.98 m (101.6 ft) NE of a
manhole cover over a concrete sewer drain, 7.32 m (24.0 ft) west of the
centerline of River Road, 1.7 m (5.6 ft) east of a utility pole, and 1.33 m (4.4
ft) east of a carsonite witness post. The datum point is the top of a stainless
steel rod driven 34.0 M (112 ft) to refusal, and encased in a 5 inch PVC pipe.
BENCH MARK STAMPING: 4044 J 2015
DESIGNATION: 876 4044 J
MONUMENTATION: Flange-encased Rod VM#: 21596
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 29° 39.7' N ( 29.66219) LONGITUDE: 91° 14.6' W ( -91.24339)
The bench mark is a flange-encased rod located 31.71 m (104.0 ft) west of a
utility pole on the eastern edge of River Road, 18.86 m (61.9 ft) SW of the
southernmost yellow marker for an underground pipeline, 13.69 m (44.9 ft) WNW of
the centerline of River Road, and 8.90 m (29.2 ft) SSE of a chain link fence
surrounding a concrete pad. The datum point is the top of a stainless steel rod
driven 27.4 m (90 ft) to refusal, and encased in a 5 inch PVC pipe.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8764044 PUBLICATION DATE: 05/19/2020
Name: BERWICK, ATCHAFALAYA RIVER, LA
LA
NOAA Chart: 11355 Latitude: 29° 40.1' N ( 29.66750)
USGS Quad: MORGAN CITY Longitude: 91° 14.3' W ( -91.23761)
T I D A L D A T U M S
Tidal datums at BERWICK, ATCHAFALAYA RIVER, LA based on:
LENGTH OF SERIES: 12 YEARS
TIME PERIOD: 12/03-11/04, 7/07-6/08, 11/08-10/12, 2/13-1/19
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8770570 SABINE PASS NORTH
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (07/13/2019) = 2.214
MEAN HIGHER HIGH WATER MHHW = 0.162
MEAN HIGH WATER MHW = 0.150
MEAN SEA LEVEL MSL = 0.088
MEAN TIDE LEVEL MTL = 0.081
MEAN LOW WATER MLW = 0.013
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum NAVD88 = -0.504
LOWEST OBSERVED WATER LEVEL (08/29/2012) = -0.831
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
4044 E 2003 -0.972 -1.122
4044 C 2003 -0.723 -0.873
4044 D 2003 -0.869 -1.019
4044 H 2015 -1.044 -1.194
4044 J 2015 0.315 0.165
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8764044 PUBLICATION DATE: 05/19/2020
Name: BERWICK, ATCHAFALAYA RIVER, LA
LA
NOAA Chart: 11355 Latitude: 29° 40.1' N ( 29.66750)
USGS Quad: MORGAN CITY Longitude: 91° 14.3' W ( -91.23761)
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.