U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
Station ID: 8661093 PUBLICATION DATE: 01/06/2004
Name: YAUHANNAH BRIDGE, PEE DEE RIVER
SC
NOAA Chart: 11535 Latitude: 33° 39.6' N ( 33.66000)
USGS Quad: YAUHANNAH Longitude: 79° 9.3' W ( -79.15500)
To reach the tidal bench marks from the intersection of U.S. Highways 17 and 701
in Georgetown, proceed north on U.S. Highway 701 for 38.0 km (23.6 mi) to the SW
end of the Yauhannah Bridge, then turn left and proceed NE along a dirt road for
0.2 km (0.1 mi) to the river basin on the NW side of the highway. The bench
marks are in the vicinity of Yauhannah Bridge. The tide gage and staff were on
the SW bank of the Pee Dee River.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1093 A 1981
DESIGNATION: 866 1093 A
MONUMENTATION: Tidal Station disk VM#: 3742
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 33° 39.6' N ( 33.66000) LONGITUDE: 79° 9.3' W ( -79.15500)
The primary bench mark is a disk located NW of the Yauhannah Bridge, 77 m (252
ft) north of Bench Mark 1093 B 1981, 4.30 m (14.1 ft) NE of the centerline of
the dirt road, 2.68 m (8.8 ft) SE of a 0.61 m (2.0 ft) diameter gum tree, 2.38 m
(7.8 ft) south of the SW bank of Pee Dee River, and 2.16 m (7.1 ft) east of a
0.61 m (2.0 ft) diameter oak tree. The bench mark is 0.06 m (0.2 ft) below the
ground surface crimped to the top of a copper-clad steel rod driven 14.6 m (48
ft) to refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
Station ID: 8661093 PUBLICATION DATE: 01/06/2004
Name: YAUHANNAH BRIDGE, PEE DEE RIVER
SC
NOAA Chart: 11535 Latitude: 33° 39.6' N ( 33.66000)
USGS Quad: YAUHANNAH Longitude: 79° 9.3' W ( -79.15500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1093 B 1981
DESIGNATION: 866 1093 B
MONUMENTATION: Tidal Station disk VM#: 3743
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 33° 39.6' N ( 33.66000) LONGITUDE: 79° 9.3' W ( -79.15500)
The bench mark is a disk located west of the Yauhannah Bridge, 69 m (228 ft) NE
of Bench Mark 1093 C 1981, 10.30 m (33.8 ft) NNE of the fourth bridge pier SW of
the SW side of the river, and 4.27 m (14.0 ft) SE of the centerline of the dirt
road. The bench mark is at ground level crimped to the top of a copper-clad
steel rod driven 14.6 m (48 ft) to refusal, and encased in a PVC pipe and
concrete kickblock.
BENCH MARK STAMPING: 1093 C 1981
DESIGNATION: 866 1093 C
MONUMENTATION: Tidal Station disk VM#: 3744
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 33° 39.6' N ( 33.66000) LONGITUDE: 79° 9.3' W ( -79.15500)
The bench mark is a disk located SW of the Yauhannah Bridge, 49 m (160 ft) NE of
Bench Mark Y 122 1962, 5.73 m (18.8 ft) SSW of the tenth bridge pier and 3.72 m
(12.2 ft) north of the eleventh bridge pier SW of the SW side of the river, and
2.56 m (8.4 ft) SE of the centerline of the dirt road. The bench mark is 6 cm
(0.2 ft) below the ground surface, crimped to the top of a copper-clad steel rod
driven 14.6 m (48 ft) to refusal, and encased in a PVC pipe and concrete
kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
Station ID: 8661093 PUBLICATION DATE: 01/06/2004
Name: YAUHANNAH BRIDGE, PEE DEE RIVER
SC
NOAA Chart: 11535 Latitude: 33° 39.6' N ( 33.66000)
USGS Quad: YAUHANNAH Longitude: 79° 9.3' W ( -79.15500)
T I D A L D A T U M S
Tidal datums at YAUHANNAH BRIDGE, PEE DEE RIVER based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: August 1982 - November 1982
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:
MEAN HIGHER HIGH WATER MHHW = 0.578
MEAN HIGH WATER MHW = 0.547
MEAN SEA LEVEL MSL = 0.326
MEAN TIDE LEVEL MTL = 0.293
MEAN LOW WATER MLW = 0.040
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1093 A 1981 1.663 1.116
1093 B 1981 0.934 0.387
1093 C 1981 0.877 0.330
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
Station ID: 8661093 PUBLICATION DATE: 01/06/2004
Name: YAUHANNAH BRIDGE, PEE DEE RIVER
SC
NOAA Chart: 11535 Latitude: 33° 39.6' N ( 33.66000)
USGS Quad: YAUHANNAH Longitude: 79° 9.3' W ( -79.15500)
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.