Superseded Bench Mark Sheet for 8720596, EAST TOCOI, ST. JOHNS RIVER FL

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  4

                                                   PUBLICATION DATE:  07/23/1992
Station ID: 8720596                                SUPERCEDED DATE:   04/21/2003
Name:       EAST TOCOI, ST. JOHNS RIVER                       
            FLORIDA
NOAA Chart: 11492                                  Latitude:         29° 51.5' N
USGS Quad:  RIVERDALE                              Longitude:        81° 33.2' W


To reach the tidal bench marks from the intersection of U.S. Highway 1 and State
Road C-214 (Tocoi Road) in St. Augustine, proceed west on State Road C-214 for
15.6 miles (25.1 km) to State Road 13, proceed NE on State Road 13 for 0.9 mile
(1.4 km) to the Tocoi Fish Camp on the west side of the highway.  The bench
marks are along State Roads 13 and C-214.  The tide gauge and staff were at the
NW corner of the southernmost dock at the fish camp.


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


                 PRIMARY BENCH MARK STAMPING:  0596 A 1978

MONUMENTATION:           Survey Disk                               VM#:     5221
AGENCY:                                                            PID#:  AQ2636
SETTING CLASSIFICATION:  Concrete Pad


The primary bench mark is set flush in a 4 x 6-foot (1 x 2 m) concrete pad at
the entrance to the Tocoi Fish Camp store, 1900 feet (579 m) north of Bench Mark
0596 B 1978, 45 feet (13 m) west of the centerline of State Road 13, and 9.2
feet (2.8 m) east of the camp store.



                         BENCH MARK STAMPING:  NO 1 1934

MONUMENTATION:           Survey Disk                               VM#:     5219
AGENCY:                                                            PID#:  AQ2632
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set flush in the top of a 1.0-foot (0.3 m) square concrete
monument, south of the intersection of State Roads 13 and C-214, 51 feet (15 m)
east of the centerline of State Road 13, 49 feet (15 m) south of the centerline
of State Road C-214, 39.5 feet (12.0 m) NW of the north corner of an abandoned
concrete block building, 9 feet (3 m) east of a former gasoline sign, and at
ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                   PUBLICATION DATE:  07/23/1992
Station ID: 8720596                                SUPERCEDED DATE:   04/21/2003
Name:       EAST TOCOI, ST. JOHNS RIVER                       
            FLORIDA
NOAA Chart: 11492                                  Latitude:         29° 51.5' N
USGS Quad:  RIVERDALE                              Longitude:        81° 33.2' W


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


                         BENCH MARK STAMPING:  NO 3 1934

MONUMENTATION:           Survey Disk                               VM#:     5220
AGENCY:                                                            PID#:  AQ2633
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set flush in the top of a 1.0-foot (0.3 m) square concrete
monument, north of the intersection of State Roads 13 and C-214, 288 feet (88 m)
north of the centerline of State Road C-214, 163 feet (50 m) north of the north
end of the east headwall of a culvert under the highway, 47 feet  (14 m) east of
the centerline of State Road 13, 1.5 feet (0.5 m) west of a fence, and at ground
level.



                         BENCH MARK STAMPING:  0596 B 1978

MONUMENTATION:           Survey Disk                               VM#:     5222
AGENCY:                                                            PID#:  AQ2635
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set flush in a concrete monument, 1300 feet (396 m) north of
Bench Mark 0596 C 1978, 75.5 feet (23.0 m) north of a 3-foot (1 m) diameter oak
tree, 42.2 feet (12.9 m) west of the centerline of State Road 13, 42.2 feet
(12.9 m) south of the centerline of a dirt road leading west to the K.D. Shannon
residence, and 1.6 feet (0.5 m) east of a witness post.



                         BENCH MARK STAMPING:  0596 C 1978

MONUMENTATION:           Survey Disk                               VM#:     5223
AGENCY:                                                            PID#:  AQ2634
SETTING CLASSIFICATION:  Highway Culvert


The bench mark is set flush in the north end of a highway culvert, 1320 feet
(402 m) NNE of Bench Mark NO 3 1934, 65 feet (20 m) east of St. Johns River, 23
feet (7 m) east of the centerline of State Road 13, and 2.3 feet (0.7 m) south
of a witness post.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  4

                                                   PUBLICATION DATE:  07/23/1992
Station ID: 8720596                                SUPERCEDED DATE:   04/21/2003
Name:       EAST TOCOI, ST. JOHNS RIVER                       
            FLORIDA
NOAA Chart: 11492                                  Latitude:         29° 51.5' N
USGS Quad:  RIVERDALE                              Longitude:        81° 33.2' W


                            T I D A L   D A T U M S 


Tidal datums at EAST TOCOI, ST. JOHNS RIVER based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           SEPTEMBER - NOVEMBER 1978
     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)         =   2.34
     MEAN HIGHER HIGH WATER                     MHHW   =   1.02
     MEAN HIGH WATER                            MHW    =   0.97
     MEAN TIDE LEVEL                            MTL    =   0.52
     MEAN LOW WATER                             MLW    =   0.07
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (01/26/1979)         =  -1.12

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     0596 A 1978                                 5.71      4.74
     NO 1 1934                                   9.82      8.85
     NO 3 1934                                  10.57      9.60
     0596 B 1978                                10.53      9.56
     0596 C 1978                                11.33     10.36


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  4

                                                   PUBLICATION DATE:  07/23/1992
Station ID: 8720596                                SUPERCEDED DATE:   04/21/2003
Name:       EAST TOCOI, ST. JOHNS RIVER                       
            FLORIDA
NOAA Chart: 11492                                  Latitude:         29° 51.5' N
USGS Quad:  RIVERDALE                              Longitude:        81° 33.2' 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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