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Bench Mark Sheet for 8668223, BROAD RIVER BRIDGE SC

Superseded Epoch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Small blue map location marker Unpublished bench mark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  4

                                                                                
Station ID: 8668223                         PUBLICATION DATE:  03/09/2004
Name:       BROAD RIVER BRIDGE                                
            SC
NOAA Chart: 11513                           Latitude:   32° 23.2' N (  32.38670)
USGS Quad:  LAUREL BAY                      Longitude:  80° 46.6' W ( -80.77670)


To reach the tidal bench marks from the intersection of U.S. Highway 21 and
State Highway 280 in Burton, proceed south on State Highway 280 for 2.1 km (1.3
mi), then SW on State Highway 170 for 6.0 km (3.7 mi) to the NE end of the
Edward Burton Rogers Bridge across Broad River.  The bench marks are located
north of the bridge along State Highway 170.  The tide gage and staff were
located at the southern end of the bridge on a wooden fishing platform, 224 m
(735 ft) from the NE end of bridge.


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


                 PRIMARY BENCH MARK STAMPING:  F 104 1962
                         DESIGNATION:          F 104

MONUMENTATION:           Bench Mark disk                       VM#:        12094
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  CK0904
SETTING CLASSIFICATION:  Bridge abutment                       OPUS PID#: CK0904
LATITUDE:   32° 23.4' N (  32.39000)          LONGITUDE:  80° 46.5' W ( -80.77500)


The primary bench mark is a disk set flush in the SE abutment at the NE end of
the bridge, 32.74 m (107.4 ft) SW of a power pole #330707 with two transformers
and two guy wires, 15.97 m (52.4 ft) west of a telephone junction box support
pole #63, 5.18 m (17.0 ft) SSE of the centerline of State Highway 170, and .15 m
(0.5 ft) above the highway. 

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                                                
Station ID: 8668223                         PUBLICATION DATE:  03/09/2004
Name:       BROAD RIVER BRIDGE                                
            SC
NOAA Chart: 11513                           Latitude:   32° 23.2' N (  32.38670)
USGS Quad:  LAUREL BAY                      Longitude:  80° 46.6' W ( -80.77670)


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


                         BENCH MARK STAMPING:  8223 B 1978
                         DESIGNATION:          866 8223 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        12097
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  CK2160
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   32° 23.5' N (  32.39170)          LONGITUDE:  80° 46.4' W ( -80.77330)


The bench mark is a disk located 0.2 km (0.1 mi) ENE of bench mark 8223 A 1978,
43.56 m (142.9 ft) ENE of a Speed Limit 55 sign on State Highway 170, 27.80 m
(91.2 ft) SSW of a 0.61 m (2 ft) diameter pine tree with a SCGS reference washer
attatched, 22.65 m (74.3 ft) south of a 0.30 m (1.0 ft) cedar tree with a SCGS
reference washer attatched, 7.68 m (25.2 ft) SSE of the centerline of State
Highway 170, 4 m (13 ft) SSW of the shrub line along the marsh, and 0.67 m (2.2
ft) ENE of a witness post with sign.  The bench mark is set 0.52 m (1.7 ft)
below highway level, crimped to the top of a stainless steel rod driven 12.8 m
(42 ft) to refusal, and encased in a 5-inch PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  8223 C 1978
                         DESIGNATION:          866 8223 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        12098
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  CK2161
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   32° 23.5' N (  32.39170)          LONGITUDE:  80° 46.3' W ( -80.77170)


The bench mark is a disk located 7.22 m (23.7 ft) NW of the centerline of State
Highway 170, 4.48 m (14.7 ft) SE of the pine tree with a SCGS reference washer
attatched, 1.92 m (6.3 ft) SSE of a fiber optic cable warning post, and 1.58 m
(5.2 ft) SE of a witness post.  The bench mark is set at ground level, crimped
to the top of a stainless steel rod driven 20.1 m (66 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  4

                                                                                
Station ID: 8668223                         PUBLICATION DATE:  03/09/2004
Name:       BROAD RIVER BRIDGE                                
            SC
NOAA Chart: 11513                           Latitude:   32° 23.2' N (  32.38670)
USGS Quad:  LAUREL BAY                      Longitude:  80° 46.6' W ( -80.77670)


                            T I D A L   D A T U M S 


Tidal datums at BROAD RIVER BRIDGE based on:

     LENGTH OF SERIES:      1 YEAR
     TIME PERIOD:           August 1981 - July 1982
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8670870 FORT PULASKI, SAVANNAH RIVER


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

     HIGHEST OBSERVED WATER LEVEL (11/13/1981)         =  3.102
     MEAN HIGHER HIGH WATER                     MHHW   =  2.413
     MEAN HIGH WATER                            MHW    =  2.300
     North American Vertical Datum              NAVD88 =  1.337
     MEAN SEA LEVEL                             MSL    =  1.302
     MEAN TIDE LEVEL                            MTL    =  1.181
     MEAN LOW WATER                             MLW    =  0.062
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/10/1982)         = -0.830

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     F 104 1962                                  5.906    3.606
     8223 B 1978                                 4.380    2.080
     8223 C 1978                                 4.579    2.279


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

                                                                                
Station ID: 8668223                         PUBLICATION DATE:  03/09/2004
Name:       BROAD RIVER BRIDGE                                
            SC
NOAA Chart: 11513                           Latitude:   32° 23.2' N (  32.38670)
USGS Quad:  LAUREL BAY                      Longitude:  80° 46.6' W ( -80.77670)


                             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 8668223 BROAD RIVER BRIDGE, SC

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