Superseded Bench Mark Sheet for 8663618, MC CLELLANVILLE, JEREMY CREEK SC

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                   PUBLICATION DATE:  11/21/1990
Station ID: 8663618                                SUPERCEDED DATE:   04/21/2003
Name:       MC CLELLANVILLE, JEREMY CREEK                     
            SOUTH CAROLINA
NOAA Chart: 11531                                  Latitude:         33°  4.7' N
USGS Quad:  MC CLELLANVILLE                        Longitude:        79° 27.6' W


To reach the tidal bench marks from the intersection of U.S. Highway 17/701 and
State Highway 45 in a community known locally as Moores Corner, proceed SE on
State Highway 45 for 1.5 miles (2.4 km) through Mc Clellanville to the South
Carolina Crab Company dock.  The bench marks are near the crab company and on
adjacent municipal grounds.  The tide gage and staff were on the SW corner ofthe
crab company dock.


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


                 PRIMARY BENCH MARK STAMPING:  JC NO 1 1975

MONUMENTATION:           Survey Disk                               VM#:     3998
AGENCY:                                                            PID#:  DD0963
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is set along the south side of the dirt road leading from the
south end of Pinckney Street to South Carolina Crab Company, about 225 feet  
(69 m) east of the crab company, 101 feet (31 m) NNW of the NW corner of the
last house on the south side of the road, 19.0 feet (5.8 m) SE of the center-
line of the dirt road, and 5.4 feet (1.6 m) SW of power pole #88972.  The bench
mark is crimped to a copper-clad steel rod driven an unspecified depth to
refusal, and encased in a 4-inch PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  JC NO 2 1975

MONUMENTATION:           Survey Disk                               VM#:     3999
AGENCY:                                                            PID#:  DD0962
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is set along the south side of a chain link fence separating  
the municipal grounds from the crab company, about 150 feet (46 m) NW of Bench
Mark JC NO 1 1975, 20.8 feet (6.3 m) NE of a multi-trunked cedar tree, 16.8 feet
(5.1 m) SSW of the SW corner post of the chain link fence, and 2 feet    (1 m)
NW of a metal witness post.  The bench mark is 0.1 foot (0.03 m) below grade,
crimped to a copper-clad steel rod driven an unspecified depth to refusal, 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  5

                                                   PUBLICATION DATE:  11/21/1990
Station ID: 8663618                                SUPERCEDED DATE:   04/21/2003
Name:       MC CLELLANVILLE, JEREMY CREEK                     
            SOUTH CAROLINA
NOAA Chart: 11531                                  Latitude:         33°  4.7' N
USGS Quad:  MC CLELLANVILLE                        Longitude:        79° 27.6' W


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


                         BENCH MARK STAMPING:  JC NO 3 1975

MONUMENTATION:           Survey Disk                               VM#:     4000
AGENCY:                                                            PID#:  DD0961
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is set near the SW corner of the municipal offices parking lot,
about 135 feet (41 m) north of Bench Mark JC NO 2 1975, 24.3 feet (7.4 m) SE of
the town flagpole, 14.0 feet (4.3 m) NE of the NW corner post of a chain link
fence, and 3.0 feet (0.9 m) NNW of the fence.  The bench mark is crimped to a
copper-clad steel rod driven an unspecified depth to refusal, and encased in a
4-inch PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  JC NO 4 1975

MONUMENTATION:           Survey Disk                               VM#:     4001
AGENCY:                                                            PID#:  DD0960
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is set along the west edge of the municipal offices parking lot,
about 45 feet (14 m) north of Bench Mark JC NO 3 1975, 44.5 feet (13.6 m) NNE of
the NW corner post of a chain link fence, 18.8 feet (5.7 m) NE of the town
flagpole, 7.6 feet (2.3 m) east of a 3-foot (1 m) square water main made from
concrete blocks, and 1.8 feet (0.5 m) NE of a metal witness post.  The bench
mark is crimped to a copper-clad steel rod driven an unspecified depth to
refusal, 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  3 of  5

                                                   PUBLICATION DATE:  11/21/1990
Station ID: 8663618                                SUPERCEDED DATE:   04/21/2003
Name:       MC CLELLANVILLE, JEREMY CREEK                     
            SOUTH CAROLINA
NOAA Chart: 11531                                  Latitude:         33°  4.7' N
USGS Quad:  MC CLELLANVILLE                        Longitude:        79° 27.6' W


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


                         BENCH MARK STAMPING:  JC NO 5 1975

MONUMENTATION:           Survey Disk                               VM#:     4002
AGENCY:                                                            PID#:  DD0959
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is set near Mc Clellanville Lookout Tower, about 120 feet (37 m)
north of Bench Mark JC NO 4 1975, 33.0 feet (10.0 m) NW of a 0.3-foot (0.1 m)
diameter pipe supporting a basketball backboard, 15.5 feet (4.7 m) ESE of a
1.3-foot (0.4 m) diameter pine tree, 3.9 feet (1.2 m) SSW of the SW corner post
of the fence around the tower, and 2.0 feet (0.6 m) east of a metal witness
post.  The bench mark is crimped to a copper-clad steel rod driven an
unspecified depth to refusal, 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  4 of  5

                                                   PUBLICATION DATE:  11/21/1990
Station ID: 8663618                                SUPERCEDED DATE:   04/21/2003
Name:       MC CLELLANVILLE, JEREMY CREEK                     
            SOUTH CAROLINA
NOAA Chart: 11531                                  Latitude:         33°  4.7' N
USGS Quad:  MC CLELLANVILLE                        Longitude:        79° 27.6' W


                            T I D A L   D A T U M S 


Tidal datums at MC CLELLANVILLE, JEREMY CREEK based on:

     LENGTH OF SERIES:      9 MONTHS
     TIME PERIOD:           JULY 1975-JUNE 1976
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8665530 CHARLESTON


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

     HIGHEST OBSERVED WATER LEVEL (10/05/1975)         =   7.36
     MEAN HIGHER HIGH WATER                     MHHW   =   5.53
     MEAN HIGH WATER                            MHW    =   5.16
     MEAN TIDE LEVEL                            MTL    =   2.67
     MEAN LOW WATER                             MLW    =   0.19
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (04/16/1976)         =  -0.81

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     JC NO 1 1975                               10.40      5.24
     JC NO 2 1975                                8.83      3.67
     JC NO 3 1975                                8.36      3.20
     JC NO 4 1975                                8.28      3.12
     JC NO 5 1975                                8.62      3.46


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                   PUBLICATION DATE:  11/21/1990
Station ID: 8663618                                SUPERCEDED DATE:   04/21/2003
Name:       MC CLELLANVILLE, JEREMY CREEK                     
            SOUTH CAROLINA
NOAA Chart: 11531                                  Latitude:         33°  4.7' N
USGS Quad:  MC CLELLANVILLE                        Longitude:        79° 27.6' W


                             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 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 8663618 MC CLELLANVILLE, JEREMY CREEK, SC