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Bench Mark Sheet for 8729974, PERDIDO KEY, OLD RIVER FL

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                                                
Station ID: 8729974                         PUBLICATION DATE:  06/28/2004
Name:       PERDIDO KEY, OLD  RIVER                           
            FL
NOAA Chart: 11382                           Latitude:   30° 18.0' N (  30.30000)
USGS Quad:  PERDIDO BAY                     Longitude:  87° 26.9' W ( -87.44830)


To reach the tidal bench marks from the south end of the State Road 292 bridge
over Old River at Perdido Key, proceed SW on State Road 292 for 3.7 km (2.3 mi)
to River Road, then turn right and proceed NE on the paved road for 0.6 km (0.4
mi) to house # 1017 (R.J. Bell residence).  The bench marks are along River
Road.  The tide gage and staff were located on a dock at the Bell residence.


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


                 PRIMARY BENCH MARK STAMPING:  9974 A 1977
                         DESIGNATION:          872 9974 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10332
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BG3646
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 18.0' N (  30.30000)          LONGITUDE:  87° 26.8' W ( -87.44670)


The primary bench mark is a disk located near the east corner of the Bell
property, 20.57 m (67.5 ft) east of bench mark 9974 E 1977, 8.60 m (28.2 ft) NW
of the centerline of the paved road, and 2.13 m (7.0 ft) NE of a powerline pole,
and 0.15 m (0.5 ft) SE of a witness post.  The bench mark is set 6 cm (0.2 ft)
below ground level, crimped to the top of a copper-clad steel rod driven an
unspecified depth 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

                                                                                
Station ID: 8729974                         PUBLICATION DATE:  06/28/2004
Name:       PERDIDO KEY, OLD  RIVER                           
            FL
NOAA Chart: 11382                           Latitude:   30° 18.0' N (  30.30000)
USGS Quad:  PERDIDO BAY                     Longitude:  87° 26.9' W ( -87.44830)


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


                         BENCH MARK STAMPING:  9974 B 1977
                         DESIGNATION:          872 9974 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10333
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BG3644
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 17.9' N (  30.29830)          LONGITUDE:  87° 26.9' W ( -87.44830)


The bench mark is a disk located 117 m (385 ft) SW of bench mark 9974 A 1977, 19
m (62 ft) SW of the center of a drainage ditch, 8 m (25 ft) NE of a powerline
pole, 7 m (23 ft) NW of the centerline of the paved road, and 0.15 m (0.5 ft) SE
of a witness post.   The bench mark is set 0.15 m (0.5 ft) below ground level,
crimped to the top of a copper-clad steel rod driven an unspecified depth to
refusal, and encased in a PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  9974 C 1977
                         DESIGNATION:          872 9974 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10334
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BG3643
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID#: BG3643
LATITUDE:   30° 17.9' N (  30.29830)          LONGITUDE:  87° 27.0' W ( -87.45000)


The bench mark is a disk located 91 m (300 ft) SW of bench mark 9974 B 1977,
26.37 m (86.5 ft) east of the east corner of house # 1018, 5.61 m (18.4 ft) NW
of the centerline of the paved road, and 0.15 m (0.5 ft) SE of a witness post. 
The bench mark is set 9 cm (0.3 ft) below ground level, crimped to the top of a
copper-clad steel rod driven an unspecified depth 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

                                                                                
Station ID: 8729974                         PUBLICATION DATE:  06/28/2004
Name:       PERDIDO KEY, OLD  RIVER                           
            FL
NOAA Chart: 11382                           Latitude:   30° 18.0' N (  30.30000)
USGS Quad:  PERDIDO BAY                     Longitude:  87° 26.9' W ( -87.44830)


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


                         BENCH MARK STAMPING:  9974 E 1977
                         DESIGNATION:          872 9974 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10336
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BG3645
SETTING CLASSIFICATION:  Concrete pump slab                    OPUS PID:        
LATITUDE:   30° 18.0' N (  30.30000)          LONGITUDE:  87° 26.8' W ( -87.44670)


The bench mark is a disk set in the top of the NW corner of a concrete slab for
a water pump, 22.98 m (75.4 ft) SE of the east corner of house # 1017, 20.57 m
(67.5 ft) west of bench mark 9974 A 1977 and 10 m (33 ft) NE of the centerline
of the driveway to the house.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 8729974                         PUBLICATION DATE:  06/28/2004
Name:       PERDIDO KEY, OLD  RIVER                           
            FL
NOAA Chart: 11382                           Latitude:   30° 18.0' N (  30.30000)
USGS Quad:  PERDIDO BAY                     Longitude:  87° 26.9' W ( -87.44830)


                            T I D A L   D A T U M S 


Tidal datums at PERDIDO KEY, OLD  RIVER based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           February 1994 - March 1994
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8729840 PENSACOLA, PENSACOLA BAY


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     MEAN HIGHER HIGH WATER                     MHHW   =  0.247
     MEAN HIGH WATER                            MHW    =  0.239
     MEAN TIDE LEVEL                            MTL    =  0.117
     MEAN SEA LEVEL                             MSL    =  0.115
     North American Vertical Datum              NAVD88 =  0.008
     MEAN LOW WATER                             MLW    =  0.007
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     9974 A 1977                                 1.120    0.881
     9974 B 1977                                 0.832    0.593
     9974 C 1977                                 1.621    1.382
     9974 E 1977                                 1.491    1.252


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                                                
Station ID: 8729974                         PUBLICATION DATE:  06/28/2004
Name:       PERDIDO KEY, OLD  RIVER                           
            FL
NOAA Chart: 11382                           Latitude:   30° 18.0' N (  30.30000)
USGS Quad:  PERDIDO BAY                     Longitude:  87° 26.9' W ( -87.44830)


                             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.

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Products available at 8729974 PERDIDO KEY, OLD RIVER, FL

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services