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Bench Mark Sheet for 8761487, CHEF MENTEUR, CHEF MENTEUR PASS LA

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  6

                                                                                
Station ID: 8761487                         PUBLICATION DATE:  05/07/2003
Name:       CHEF MENTEUR, CHEF MENTEUR PASS                   
            LA
NOAA Chart: 11369                           Latitude:   30°  3.9' N (  30.06500)
USGS Quad:  CHEF MENTEUR                    Longitude:  89° 48.0' W ( -89.80000)


To reach the tidal bench marks from the NE end of the U.S. Highway 90 bridge
over Chef Menteur Pass, proceed south on a shell road for 0.5 km (0.3 mi) to the
Tally-Ho Club on the right.  The bench marks are in the vicinity of the club and
north along the shell road.  The tide gage and staff were located at the NW end
of the small dock in front of the club.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  1487 A 1982
                         DESIGNATION:          876 1487 A

MONUMENTATION:           Tidal Station disk                    VM#:         7171
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   30°  3.9' N (  30.06500)          LONGITUDE:  89° 48.0' W ( -89.80000)


The primary bench mark is a disk located at the Tally-Ho Club, 15 m (48 ft) NNW
of light pole #117, 13 m (42 ft) west of the NW corner of the club house porch,
8 m (25 ft) SE of the SE wall of a tin boat shed, and 1 m (4 ft) NE of the
wooden bulkhead. The bench mark is set 12 cm (0.4 ft) below ground level,
crimped to the top of a stainless steel rod driven 23.2 m (76 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  2 of  6

                                                                                
Station ID: 8761487                         PUBLICATION DATE:  05/07/2003
Name:       CHEF MENTEUR, CHEF MENTEUR PASS                   
            LA
NOAA Chart: 11369                           Latitude:   30°  3.9' N (  30.06500)
USGS Quad:  CHEF MENTEUR                    Longitude:  89° 48.0' W ( -89.80000)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  WES 11 1978
                         DESIGNATION:          876 1487 WES 11

MONUMENTATION:           Survey disk                           VM#:         7172
AGENCY:                  US Army Corps of Engineers (USE)      IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30°  3.9' N (  30.06500)          LONGITUDE:  89° 48.0' W ( -89.80000)


The bench mark is a disk located 0.5 km (0.3 mi) south on a shell road from the
NE end of the U.S. Highway 90 bridge over Chef Menteur Pass, 26.33 m (86.4 ft)
ENE of the south corner of Harbor Cottage Camp, 19.39 m (63.6 ft) NNE of the
north corner of a grey boat shed, 3 m (9 ft) SW of the centerline of the road,
2.35 m (7.7 ft) north of a creosote post, and 0.6 m (2 ft) NE of a witness post.
 The bench mark is crimped to the top of a copper-clad steel rod driven 9.1 m
(30 ft) to substantial resistance and encased in a 6-inch PVC pipe.



                         BENCH MARK STAMPING:  WES 12 1978
                         DESIGNATION:          876 1487 WES 12

MONUMENTATION:           Survey disk                           VM#:         7173
AGENCY:                  US Army Corps of Engineers (USE)      IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30°  3.9' N (  30.06500)          LONGITUDE:  89° 48.0' W ( -89.80000)


The bench mark is a disk located 0.6 km (0.4 mi) south on a shell road from the
NE end of the U.S. Highway 90 bridge over Chef Menteur Pass, 16 m (54 ft) east
of the SE corner of the Tally-Ho Club building, 1.37 m (4.5 ft) SE of a power
pole with transformer, and 1 m (2 ft) east of a witness post and sign.  The
bench mark is crimped to a copper-clad steel rod driven 33.5 m (110 ft) to
substantial resistance and encased in a 6-inch PVC pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                                                
Station ID: 8761487                         PUBLICATION DATE:  05/07/2003
Name:       CHEF MENTEUR, CHEF MENTEUR PASS                   
            LA
NOAA Chart: 11369                           Latitude:   30°  3.9' N (  30.06500)
USGS Quad:  CHEF MENTEUR                    Longitude:  89° 48.0' W ( -89.80000)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  WES 13 1978
                         DESIGNATION:          876 1487 WES 13

MONUMENTATION:           Survey disk                           VM#:         7174
AGENCY:                  US Army Corps of Engineers (USE)      IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30°  3.9' N (  30.06500)          LONGITUDE:  89° 48.0' W ( -89.80000)


The bench mark is a disk located 0.8 km (0.5 mi) south on a shell road from the
NE end of the U.S. Highway 90 bridge over Chef Menteur Pass, 11.98 m (39.3 ft)
east of the SE corner of an elevated camp house, 5 m (16 ft) NE of power pole
#453C, 4.11 m (13.5 ft) west of the NW end of a wooden bridge, and 1 m (2 ft)
NNE of a witness post and sign.  The bench mark is crimped to a copper-clad
steel rod driven 35.1 m (115 ft) to substantial resistance, and encased in a
6-inch plastic pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                                                
Station ID: 8761487                         PUBLICATION DATE:  05/07/2003
Name:       CHEF MENTEUR, CHEF MENTEUR PASS                   
            LA
NOAA Chart: 11369                           Latitude:   30°  3.9' N (  30.06500)
USGS Quad:  CHEF MENTEUR                    Longitude:  89° 48.0' W ( -89.80000)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  E 3145
                         DESIGNATION:          E 3145

MONUMENTATION:           Survey disk                           VM#:         7175
AGENCY:                  Louisiana Geological Survey (LAGS)    IDB PID#:  BH1133
SETTING CLASSIFICATION:  Concrete bridge floor                 OPUS PID:        
LATITUDE:   30°  4.1' N (  30.06830)          LONGITUDE:  89° 48.2' W ( -89.80330)


The bench mark is a disk set in the concrete bridge floor at the NE end of the
U.S. Highway 90 bridge over Chef Menteur Pass, 75 m (247 ft) SW of the NE end of
the bridge, 3 m (9 ft) NW of the centerline of the bridge, 0.76 m (2.5 ft) NE of
the NE end of the steel span of the bridge, and 0.15 m (0.5 ft) SE of the SE
face of the NW guard rail base.



                         BENCH MARK STAMPING:  1487 B 1982
                         DESIGNATION:          876 1487 B

MONUMENTATION:           Tidal Station disk                    VM#:         9002
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   30°  3.9' N (  30.06500)          LONGITUDE:  89° 48.0' W ( -89.80000)


The bench mark is a disk located NW of the Tally-Ho Club along the shell road,
75 m (245 ft) NNW of bench mark WES 11 1978, 27 m (88 ft) ESE of the south bank
of a small, unnamed canal, 4 m (12 ft) NE of the centerline of the shell road
leading to the club, and 1 m (3 ft) SE of power pole #33.  The bench mark is set
9 cm (0.3 ft) below ground level, crimped to a stainless steel rod driven 21.9 m
(72 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  5 of  6

                                                                                
Station ID: 8761487                         PUBLICATION DATE:  05/07/2003
Name:       CHEF MENTEUR, CHEF MENTEUR PASS                   
            LA
NOAA Chart: 11369                           Latitude:   30°  3.9' N (  30.06500)
USGS Quad:  CHEF MENTEUR                    Longitude:  89° 48.0' W ( -89.80000)


                            T I D A L   D A T U M S 


Tidal datums at CHEF MENTEUR, CHEF MENTEUR PASS based on:

     LENGTH OF SERIES:      8 YEARS
     TIME PERIOD:           January 1983 - December 1990
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8747437 BAY WAVELAND YC, BAY ST. LOUIS


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     HIGHEST OBSERVED WATER LEVEL (01/20/1983)         =  1.659
     MEAN HIGHER HIGH WATER                     MHHW   =  0.323
     MEAN HIGH WATER                            MHW    =  0.311
     MEAN SEA LEVEL                             MSL    =  0.170
     MEAN TIDE LEVEL                            MTL    =  0.163
     MEAN LOW WATER                             MLW    =  0.016
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (04/12/1988)         = -0.853

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     1487 A 1982                                 0.659    0.348
     WES 11 1978                                 0.408    0.097
     WES 12 1978                                 0.525    0.214
     WES 13 1978                                 0.672    0.361
     E 3145                                      4.945    4.634
     1487 B 1982                                 0.339    0.028


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  6

                                                                                
Station ID: 8761487                         PUBLICATION DATE:  05/07/2003
Name:       CHEF MENTEUR, CHEF MENTEUR PASS                   
            LA
NOAA Chart: 11369                           Latitude:   30°  3.9' N (  30.06500)
USGS Quad:  CHEF MENTEUR                    Longitude:  89° 48.0' W ( -89.80000)


                             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.

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Products available at 8761487 CHEF MENTEUR, CHEF MENTEUR PASS, LA

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services