U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 01/08/1985
Station ID: 8661867 SUPERCEDED DATE: 04/21/2003
Name: LITCHFIELD BEACH
SOUTH CAROLINA
NOAA Chart: 11535 Latitude: 33° 28.3' N
USGS Quad: MAGNOLIA BEACH Longitude: 79° 6.1' W
To reach the tidal bench marks proceed 0.2 mile (0.3 km) SE along Litchfield
Boulevard from the intersection of U.S. Highway 17 and Litchfield Boulevard
leading into Litchfield Beach. The bench marks are along Highway 17 and
Litchfield Boulevard and the tide gage and staff were on the south side of the
Litchfield Boulevard bridge over a creek and marshy area.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: L.B. NO 1 1975
MONUMENTATION: Survey Disk VM#: 3878
AGENCY: PID#: DD1438
SETTING CLASSIFICATION: Concrete Post
The bench mark is at Litchfield Beach, 210 feet (64 m) west of the bridge on
Litchfield Boulevard, 35.3 feet (10.8 m) south of the centerline of the
boulevard, 6.3 feet (1.9 m) west of utility pole NO A J 3, 2.1 feet (0.6 m) ESE
of a steel witness post, and set in a concrete post 0.17 foot (0.05 m) above the
ground.
BENCH MARK STAMPING: L.B. NO 4 1975
MONUMENTATION: Survey Disk VM#: 3879
AGENCY: PID#: DD1437
SETTING CLASSIFICATION: Copper-coated Steel Rod
The bench mark is at Litchfield Beach, SE of the intersection of U.S. Highway 17
and Litchfield Boulevard, 438 feet (134 m) NE of the centerline of Litchfield
Boulevard, 99.2 feet (30.2 m) NE of a utility pole with two transformers
attached, 8.9 feet (2.7 m) SW of the west corner of a sewage pumping station,
and 2.5 feet (0.8 m) west of a steel witness post. The bench mark is 0.2 foot
(0.1 m) above ground level, crimped to a copper-coated steel rod driven 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 5
PUBLICATION DATE: 01/08/1985
Station ID: 8661867 SUPERCEDED DATE: 04/21/2003
Name: LITCHFIELD BEACH
SOUTH CAROLINA
NOAA Chart: 11535 Latitude: 33° 28.3' N
USGS Quad: MAGNOLIA BEACH Longitude: 79° 6.1' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: L.B. NO 5 1975
MONUMENTATION: Survey Disk VM#: 3880
AGENCY: PID#: DD1436
SETTING CLASSIFICATION: Copper-coated Steel Rod
The bench mark is at Litchfield Beach, 172 feet (52 m) SE of the intersection of
U.S. Highway 7 and Litchfield Boulevard, 105 feet (32 m) west of Bench Mark L.B.
NO 4 1975, 53.6 feet (16.3 m) WNW of a utility pole with two transformers
attached, 38.2 feet (11.6 m) NE of the centerline of Litchfield Boulevard, and
3.2 feet (1.0 m) south of the SW corner curbing of a Gulf Service station
parking area. The bench mark is 0.2 foot (0.1 m) above ground level, crimped to
a copper-coated steel rod driven to refusal and encased in a PVC pipe and
concrete kickblock.
BENCH MARK STAMPING: 1867 B 1982
MONUMENTATION: Survey Disk VM#: 3881
AGENCY: PID:
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is at Litchfield Beach, at the SW corner of the intersection of
U.S. Highway 17 and Litchfield Boulevard, 147.5 feet (45.0 m) north of the north
corner of a shopping center, 41.7 feet (12.7 m) SE of the centerline of
northbound U.S. Highway 17, 30.5 feet (9.3 m) NNW of a lone palm tree, 29.0 feet
(8.8 m) WSW of the centerline of Litchfield Boulevard, and 3.0 feet (0.9 m) SE
of a utility pole with a light attached. The bench mark is at ground level,
crimped to a stainless steel rod driven 40 feet (12 m) 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 5
PUBLICATION DATE: 01/08/1985
Station ID: 8661867 SUPERCEDED DATE: 04/21/2003
Name: LITCHFIELD BEACH
SOUTH CAROLINA
NOAA Chart: 11535 Latitude: 33° 28.3' N
USGS Quad: MAGNOLIA BEACH Longitude: 79° 6.1' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1867 C 1982
MONUMENTATION: Survey Disk VM#: 3882
AGENCY: PID#: DD1435
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is at Litchfield Beach, NE of the intersection of U.S. Highway 17
and Litchfield Boulevard, 75.2 feet (22.9 m) north of the north corner of a Gulf
Service station building, 39.5 feet (12.0 m) SE of the centerline of northbound
U.S. Highway 17, 29.3 feet (8.9 m) SSW of the centerline of a dirt drive leading
to a white stucco dwelling and 1.9 feet (0.6 m) east of utility pole NO 70 A.
The bench mark is at ground level, crimped to a stainless steel rod driven 40
feet (12 m) 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 4 of 5
PUBLICATION DATE: 01/08/1985
Station ID: 8661867 SUPERCEDED DATE: 04/21/2003
Name: LITCHFIELD BEACH
SOUTH CAROLINA
NOAA Chart: 11535 Latitude: 33° 28.3' N
USGS Quad: MAGNOLIA BEACH Longitude: 79° 6.1' W
T I D A L D A T U M S
Tidal datums at LITCHFIELD BEACH based on:
LENGTH OF SERIES: 7 MONTHS
TIME PERIOD: AUGUST 1975 - JULY 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) = 5.06
MEAN HIGHER HIGH WATER MHHW = 3.35
MEAN HIGH WATER MHW = 3.04
MEAN TIDE LEVEL MTL = 1.59
MEAN LOW WATER MLW = 0.15
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (08/16/1976) = -0.14
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
L.B. NO 1 1975 5.87 2.83
L.B. NO 4 1975 12.60 9.56
L.B. NO 5 1975 13.00 9.96
1867 B 1982 13.49 10.45
1867 C 1982 13.51 10.47
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 01/08/1985
Station ID: 8661867 SUPERCEDED DATE: 04/21/2003
Name: LITCHFIELD BEACH
SOUTH CAROLINA
NOAA Chart: 11535 Latitude: 33° 28.3' N
USGS Quad: MAGNOLIA BEACH Longitude: 79° 6.1' 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.