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Bench Mark Sheet for 8638491, Chester, James River VA

Superseded Epoch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Small blue map location marker Unpublished bench mark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  6

                                                                                
Station ID: 8638491                         PUBLICATION DATE:  01/17/2013
Name:       VEPCO PLANT, CHESTER, JAMES RIVER                 
            VA
NOAA Chart: 12252                           Latitude:   37° 23.0' N (  37.38330)
USGS Quad:  DREWRYS BLUFF                   Longitude:  77° 22.7' W ( -77.37830)


To reach from the intersection of I-95 and VA Route 10, drive east on VA Route
10 for 0.5 km (0.3 mi) turn left on Old Stage Road, then drive north on Old
Stage Road for 3.2 km (2.0 mi) and turn right on to Coxendale Road, continue
east on Coxendale Road 1.6 km (1.0 mi) toward the boat ramp.  The tide station
is located on an elevated concrete pad, accessible by boat only. 


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


                 PRIMARY BENCH MARK STAMPING:  NO 1 1971
                         DESIGNATION:          863 8491 NO 1

MONUMENTATION:           Bench Mark disk                       VM#:        20491
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete pile cap                     OPUS PID:        
LATITUDE:   37° 23.0' N (  37.38269)          LONGITUDE:  77° 22.7' W ( -77.37825)


The primary bench mark is a disk set on top of a concrete pile cap near the
north end of the abandoned oil dock located 47.30 m (155.2 ft) WNW of the
mooring bollard at the south end of the abandoned oil dock, 28.30 m (92.8 ft)
NNW of the SW end of a fence on the shore for the old gangway, 21.10 m (69.2 ft)
NE of the NE end of the security fence on shore, 10.30 m (33.8 ft) SW of the
mooring bollard at the north end of an abandoned oil dock, and 0.55 m (1.8 ft)
NE of the SW corner of a concrete pile cap.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                                                
Station ID: 8638491                         PUBLICATION DATE:  01/17/2013
Name:       VEPCO PLANT, CHESTER, JAMES RIVER                 
            VA
NOAA Chart: 12252                           Latitude:   37° 23.0' N (  37.38330)
USGS Quad:  DREWRYS BLUFF                   Longitude:  77° 22.7' W ( -77.37830)


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


                         BENCH MARK STAMPING:  8491 A 2011
                         DESIGNATION:          863 8491 A

MONUMENTATION:           Survey disk                           VM#:        20489
AGENCY:                  U.S. Army Corp Of Engineers (USACE)   IDB PID#:        
SETTING CLASSIFICATION:  Lamp pole foundation                  OPUS PID:        
LATITUDE:   37° 22.9' N (  37.38206)          LONGITUDE:  77° 22.7' W ( -77.37917)


The bench mark is a disk set in the concrete base of lamp pole number LP13,
48.70 m (159.8 ft) NW of a street light pole number LP19, 48.50 m (159.1 ft) NE
of a street light pole number LP17, 44.30 m (145.3 ft) SW of a power pole with
wooden buttress VF83 and 35.30 m (115.8 ft) WSW of the NW end of the chain link
fence at Dominion Power parking lot. 



                         BENCH MARK STAMPING:  ELIJAH 1978
                         DESIGNATION:          863 8491 ELIJAH

MONUMENTATION:           Survey disk                           VM#:        20490
AGENCY:                  U.S. Army Corp Of Engineers (USACE)   IDB PID#:        
SETTING CLASSIFICATION:  CONCRETE AND STEEL MOORING POST       OPUS PID:        
LATITUDE:   37° 22.9' N (  37.38208)          LONGITUDE:  77° 22.6' W ( -77.37700)


The bench mark is a disk set in the top of a concrete and steel mooring post
located 45.00 m (147.6 ft) SSE of a steel pile mooring dolphin in the James
River, 41.70 m (136.8 ft) NW of the NW corner at the bottom of the steel steps
from the parking lot, 40.50 m (132.9 ft) SE of bench mark Sprinkle, 31.90 m
(104.7 ft) NNE of the pole with lights at the parking lot, and 7.71 m (25.3 ft)
WNW of pole with lights at the boat ramp. 

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                                                
Station ID: 8638491                         PUBLICATION DATE:  01/17/2013
Name:       VEPCO PLANT, CHESTER, JAMES RIVER                 
            VA
NOAA Chart: 12252                           Latitude:   37° 23.0' N (  37.38330)
USGS Quad:  DREWRYS BLUFF                   Longitude:  77° 22.7' W ( -77.37830)


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


                         BENCH MARK STAMPING:  NO 2 1971
                         DESIGNATION:          863 8491 NO 2

MONUMENTATION:           Bench Mark disk                       VM#:        20492
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete base                         OPUS PID:        
LATITUDE:   37° 23.0' N (  37.38258)          LONGITUDE:  77° 22.8' W ( -77.38006)


The bench mark is a disk set on the top of the concrete base for the NE leg of
the large electric transmission tower closest to the west bank of the James
River located 45.40 m (148.9 ft) NNE of the NW corner of the guard shack, 32.80
m (107.6 ft) WSW of a power line pole #BF45, 32.40 m (99.7 ft) NW of a street
light pole #LP09, 26.20 m (86.0 ft) SSE of a power line pole with transformer
and meter and switches. 



                         BENCH MARK STAMPING:  SPRINKLE 1978
                         DESIGNATION:          863 8491 SPRINKLE

MONUMENTATION:           Survey disk                           VM#:        20493
AGENCY:                  U.S. Army Corp Of Engineers (USACE)   IDB PID#:        
SETTING CLASSIFICATION:  Concrete and steel mooring post       OPUS PID:        
LATITUDE:   37° 22.9' N (  37.38217)          LONGITUDE:  77° 22.6' W ( -77.37742)


The bench mark is set in the top of a concrete and steel mooring posted located
50.90 m (167.0 ft) SE of a mooring bollard on a concrete cap at the end of an
abandoned oil dock on the James River, 40.50 m (132.9 ft) NW of USACE bench mark
Elijah, 29.80 m (97.8 ft) east of a light pole TF-19, 27.20 m (89.2 ft) ENE of
most southernly post of park entrance sign and 11.80 m (38.7 ft) NE of the
center paved road to the boat ramp. 

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                                                
Station ID: 8638491                         PUBLICATION DATE:  01/17/2013
Name:       VEPCO PLANT, CHESTER, JAMES RIVER                 
            VA
NOAA Chart: 12252                           Latitude:   37° 23.0' N (  37.38330)
USGS Quad:  DREWRYS BLUFF                   Longitude:  77° 22.7' W ( -77.37830)


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


                         BENCH MARK STAMPING:  WALTER 2009
                         DESIGNATION:          WALTER

MONUMENTATION:           Survey disk                           VM#:        20494
AGENCY:                  U.S. Army Corp Of Engineers (USACE)   IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   37° 22.9' N (  37.38214)          LONGITUDE:  77° 22.7' W ( -77.37850)


The bench mark is a disk set in concrete monument located 42.40 m (139.1 ft) SE
of a power pole with wooden buttress #VF83, 39.50 m (129.6 ft) west of a power
pole #WF42, 26.30 m (86.3 ft) NW of Dominion Power sign, 22.90 m (75.1 ft) ENE
of the NW end of a chain link fence at Dominion Power parking lot, and 21.70 m
(71.2 ft) SSE of the SW end of the security warning sign. 

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                                                
Station ID: 8638491                         PUBLICATION DATE:  01/17/2013
Name:       VEPCO PLANT, CHESTER, JAMES RIVER                 
            VA
NOAA Chart: 12252                           Latitude:   37° 23.0' N (  37.38330)
USGS Quad:  DREWRYS BLUFF                   Longitude:  77° 22.7' W ( -77.37830)


                            T I D A L   D A T U M S 


Tidal datums at VEPCO PLANT, CHESTER, JAMES RIVER based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           February 2012 - April 2012
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8638610 SEWELLS POINT, HAMPTON ROADS


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.990
     MEAN HIGH WATER                            MHW    =  0.915
     MEAN SEA LEVEL                             MSL    =  0.502
     MEAN TIDE LEVEL                            MTL    =  0.476
     MEAN LOW WATER                             MLW    =  0.037
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     NO 1 1971                                   3.877    2.962
     8491 A 2011                                 8.986    8.071
     ELIJAH 1978                                 5.019    4.104
     NO 2 1971                                  10.316    9.401
     SPRINKLE 1978                               5.002    4.087
     WALTER 2009                                 7.622    6.707


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  6

                                                                                
Station ID: 8638491                         PUBLICATION DATE:  01/17/2013
Name:       VEPCO PLANT, CHESTER, JAMES RIVER                 
            VA
NOAA Chart: 12252                           Latitude:   37° 23.0' N (  37.38330)
USGS Quad:  DREWRYS BLUFF                   Longitude:  77° 22.7' W ( -77.37830)


                             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 8638491 Chester, James River, VA

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