U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 03/24/1988
Station ID: 8720653 SUPERCEDED DATE: 04/21/2003
Name: PALMETTO BLUFF, ST. JOHNS RIVER
FLORIDA
NOAA Chart: 11492 Latitude: 29° 45.8' N
USGS Quad: RIVERDALE Longitude: 81° 33.7' W
To reach the tidal bench marks from the intersection of State Road 209 and the
Seaboard Coastline Railroad in Bostwick, procced east on State Road 209 for 2.75
miles (4.43 km) to Cedar Creek Road, then north on Cedar Creek Road for 0.15
mile (0.24 km) to the dirt road leading east to the residence of Mr. Brice E.
Bell. The bench marks are in area around residence, and in the vicinity of the
intersection of Palmetto Bluff Road and Cedar Creek Road. The gage and staff
were located on a private dock in rear of the Bell residence.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1934
MONUMENTATION: Survey Disk VM#: 5224
AGENCY: PID#: AQ2595
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set in the top of a concrete monument at the east end of
Palmetto Bluff Road, 172 feet (52 m) south of Bench Mark NO 2 1934 Reset 1962,
102.5 feet (31.2 m) south of an Artesian well on the NW side of the circular end
of the road, 4 feet (1 m) west of the top of the river bank, and 0.4 foot (0.1
m) above ground level.
BENCH MARK STAMPING: NO 3 1934
MONUMENTATION: Survey Disk VM#: 5225
AGENCY: PID#: AQ2594
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set in a concrete monument near the east end of Palmetto Bluff
Road, 274.5 feet (82.7 m) SE of Bench Mark NO 2 1934 Reset 1962, 67 feet (20 m)
SE of power pole with a transformer, 40 feet (12 m) NE of the centerline of
Palmetto Bluff Road, 4.5 feet (1.4 m) NE of a fence, and 0.5 foot (0.2 m) above
ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 03/24/1988
Station ID: 8720653 SUPERCEDED DATE: 04/21/2003
Name: PALMETTO BLUFF, ST. JOHNS RIVER
FLORIDA
NOAA Chart: 11492 Latitude: 29° 45.8' N
USGS Quad: RIVERDALE Longitude: 81° 33.7' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 2 1934 RESET 1962
MONUMENTATION: Survey Disk VM#: 5226
AGENCY: PID#: AQ2597
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set in top of a concrete monument, 76.5 feet (23.3 m) north of
Bench Mark NO 4 1962, 70 feet (21 m) east of the centerline of the intersection
of Palmetto Bluff Road and Cedar Creek Road, and 0.3 foot (0.1 m) above ground
level.
BENCH MARK STAMPING: NO 4 1962
MONUMENTATION: Survey Disk VM#: 5227
AGENCY: PID#: AQ2592
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set in to of a concrete monument at the NW corner of a fence,
35.3 feet (10.8 m) SW of the centerline of Palmetto Bluff Road, and at ground
level.
BENCH MARK STAMPING: 0653 A 1978
MONUMENTATION: Survey Disk VM#: 5228
AGENCY: PID#: AQ2598
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set flush in a concrete monument, 600 feet (183 m) north of
Bench Mark NO 2 1934 Reset 1962, 30.5 feet (9.3 m) east of the centerline of
Cedar Creek Road, 24 feet (7 m) north of the centerline of the dirt road leading
east of the Brice E. Bell residence, and 1.6 feet (0.5 m) west of a power pole
with a witness post at the NW corner of the fence line surrounding the Bell
residence, and 0.2 feet (0.1 m) below ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 03/24/1988
Station ID: 8720653 SUPERCEDED DATE: 04/21/2003
Name: PALMETTO BLUFF, ST. JOHNS RIVER
FLORIDA
NOAA Chart: 11492 Latitude: 29° 45.8' N
USGS Quad: RIVERDALE Longitude: 81° 33.7' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0653 B
MONUMENTATION: Survey Disk VM#: 5229
AGENCY: PID#: AQ2596
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set flush in a concrete monument, 69 feet (21 m) ENE of the
intersection of Palmetto Bluff Road and Cedar Creek Road, 32 feet (10 m) north
of the ceterline of Palmetto Bluff Road, 19 feet (6 m) SE of Bench Mark NO 2
1934 Rest 1962, and 1.4 feet (0.4 m) above ground level.
BENCH MARK STAMPING: Y Y2 0653 C 66 66 PALMETTO
MONUMENTATION: Survey Disk VM#: 5230
AGENCY: PID#: AQ2593
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set flush in a concrete monument, 70 feet (21 m) SE of the
intersection of Palmetto Bluff Road and Cedar Creek Road, 54.3 feet (16.6 m) SE
of the Centerline of Cedar Creek Road, 34 feet (10 m) east of the largest oak
tree in the area, 31.6 feet (9.6 m) SW of the centerline of Palmetto Bluff Road,
2.4 feet (0.7 m) NE of Bench Mark NO 4 1962, 1 foot (0.3 m) north of a fence
corner, and 0.2 foot (0.1 m) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 03/24/1988
Station ID: 8720653 SUPERCEDED DATE: 04/21/2003
Name: PALMETTO BLUFF, ST. JOHNS RIVER
FLORIDA
NOAA Chart: 11492 Latitude: 29° 45.8' N
USGS Quad: RIVERDALE Longitude: 81° 33.7' W
T I D A L D A T U M S
Tidal datums at PALMETTO BLUFF, ST. JOHNS RIVER based on:
LENGTH OF SERIES: 5 MONTHS
TIME PERIOD: SEPTEMBER 1978-MARCH 1979
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8720496 GREEN COVE SPRINGS
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (11/03/1978) = 2.48
MEAN HIGHER HIGH WATER MHHW = 1.18
MEAN HIGH WATER MHW = 1.11
MEAN TIDE LEVEL MTL = 0.59
MEAN LOW WATER MLW = 0.07
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (01/26/1979) = -1.14
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
NO 1 1934 6.92 5.81
NO 3 1934 6.76 5.65
NO 2 1934 RESET 1962 8.16 7.05
NO 4 1962 7.94 6.83
0653 A 1978 5.86 4.75
0653 B 8.52 7.41
Y Y2 0653 C 66 66 PALMETTO 8.16 7.05
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 03/24/1988
Station ID: 8720653 SUPERCEDED DATE: 04/21/2003
Name: PALMETTO BLUFF, ST. JOHNS RIVER
FLORIDA
NOAA Chart: 11492 Latitude: 29° 45.8' N
USGS Quad: RIVERDALE Longitude: 81° 33.7' 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.