U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8667074 PUBLICATION DATE: 06/28/2011
Name: WIGGINS, CHEHAW RIVER
SC
NOAA Chart: 11517 Latitude: 32° 36.1' N ( 32.60170)
USGS Quad: GREEN POND Longitude: 80° 32.5' W ( -80.54170)
To reach the bench marks from the intersection of U.S. Highway 17 and State
Highway 303, proceed south on U.S. Highway 17 for 6.4 km (4.0 mi) to State Road
15162, turn left on State Road 15162 and proceed 10.8 km (6.7 mi) to State Road
15161, then turn right on State Road 15161 and proceed 3.7 km (2.3 mi) to the
end of the pavement and an old railroad crossing, then continue down a dirt road
for 2.6 km (1.6 mi) to the end of the road at a public boat landing. The bench
marks are located near the picnic pavilion and to the NW along the dirt road.
The tide gauge and staff were on the NE end of the boat landing.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7074 A 1977
DESIGNATION: 866 7074 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 11318
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2997
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 32° 36.1' N ( 32.60170) LONGITUDE: 80° 32.5' W ( -80.54170)
The primary bench mark is a disk located near the NW corner of the picnic
pavilion, 8.14 m (26.7 ft) north of a 0.48 m (1.5 ft) diameter oak tree, 7.16 m
(23.5 ft) south of the centerline of a concrete boat ramp, 5.39 m (17.7 ft) WNW
of the center post of the pavilion, 1.13 m (3.7 ft) NW of the NW corner of the
pavilion, and 0.67 m (2.2 ft) NW of a metal witness post. The bench mark is
crimped to the top of a galvanized steel rod driven 10 m (32 ft) 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
Station ID: 8667074 PUBLICATION DATE: 06/28/2011
Name: WIGGINS, CHEHAW RIVER
SC
NOAA Chart: 11517 Latitude: 32° 36.1' N ( 32.60170)
USGS Quad: GREEN POND Longitude: 80° 32.5' W ( -80.54170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7074 B 1977
DESIGNATION: 866 7074 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 11319
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 32° 36.1' N ( 32.60170) LONGITUDE: 80° 32.5' W ( -80.54170)
The bench mark is a disk set in the top of a concrete monument on the east side
of the dirt road leading to the boat landing, 45 m (148 ft) south of bench mark
7074 D 1977, 8.47 m (27.8 ft) SW of the center of a group of four oak trees,
4.45 m (14.6 ft) east of the centerline of the dirt road, 0.40 m (1.3 ft) south
of a metal witness post, and level with the ground.
BENCH MARK STAMPING: 7074 C 1977
DESIGNATION: 866 7074 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 11320
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 32° 36.1' N ( 32.60170) LONGITUDE: 80° 32.5' W ( -80.54170)
The bench mark is a disk set in the top of a concrete monument on the east side
of the dirt road leading to the boat landing, 46 m (150 ft) SE of bench mark
7074 E 1977, 4.33 m (14.2 ft) NE of the centerline of the dirt road, 4.18 m
(13.7 ft) west of a palmetto tree, and 0.70 m (2.3 ft) SW of a metal witness
post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8667074 PUBLICATION DATE: 06/28/2011
Name: WIGGINS, CHEHAW RIVER
SC
NOAA Chart: 11517 Latitude: 32° 36.1' N ( 32.60170)
USGS Quad: GREEN POND Longitude: 80° 32.5' W ( -80.54170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7074 D 1977
DESIGNATION: 866 7074 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 11321
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2996
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 32° 36.1' N ( 32.60170) LONGITUDE: 80° 32.5' W ( -80.54170)
The bench mark is a disk located on the east side of the dirt road leading to
the boat landing, 6.34 m (20.8 ft) west of a palmetto tree, 4.11 m (13.5 ft) ENE
of the centerline of the dirt road leading to the boat landing, and 0.64 m (2.1
ft) SW of a metal witness post. The bench mark is crimped to the top of a
galvanized steel rod driven 3.7 m (12 ft) to refusal and encased in a 4-inch PVC
pipe and concrete kickblock.
BENCH MARK STAMPING: 7074 E 1977
DESIGNATION: 866 7074 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 11322
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2995
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 32° 36.1' N ( 32.60170) LONGITUDE: 80° 32.5' W ( -80.54170)
The bench mark is a disk located on the west side of the dirt road just past the
curve in the road, 0.2 km (0.1 mi) WNW of the boat landing, 11.90 m (39.0 ft)
SSW of a pine tree, 4.27 m (14.0 ft) WSW of the centerline of the dirt road, and
0.5 m (1.5 ft) east of a metal witness post. The bench mark is crimped to the
top of a galvanized steel rod driven 4.3 m (14 ft) 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
Station ID: 8667074 PUBLICATION DATE: 06/28/2011
Name: WIGGINS, CHEHAW RIVER
SC
NOAA Chart: 11517 Latitude: 32° 36.1' N ( 32.60170)
USGS Quad: GREEN POND Longitude: 80° 32.5' W ( -80.54170)
T I D A L D A T U M S
Tidal datums at WIGGINS, CHEHAW RIVER based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: August 1978 - July 1979
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8665530 CHARLESTON, COOPER RIVER ENTRANCE
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (04/26/1979) = 2.406
MEAN HIGHER HIGH WATER MHHW = 2.009
MEAN HIGH WATER MHW = 1.919
MEAN SEA LEVEL MSL = 1.184
North American Vertical Datum NAVD88 = 1.157
MEAN TIDE LEVEL MTL = 1.000
MEAN LOW WATER MLW = 0.080
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (05/26/1979) = -0.529
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7074 A 1977 3.255 1.336
7074 B 1977 4.895 2.976
7074 C 1977 6.961 5.042
7074 D 1977 5.991 4.072
7074 E 1977 7.906 5.987
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8667074 PUBLICATION DATE: 06/28/2011
Name: WIGGINS, CHEHAW RIVER
SC
NOAA Chart: 11517 Latitude: 32° 36.1' N ( 32.60170)
USGS Quad: GREEN POND Longitude: 80° 32.5' W ( -80.54170)
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.