Superseded Bench Mark Sheet for 8638481, Hopewell VA

Present Epoch

Printable version

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

                                                   PUBLICATION DATE:  04/23/1990
Station ID: 8638481                                SUPERCEDED DATE:   04/21/2003
Name:       CITY POINT, HOPEWELL, JAMES RIVER                 
            VIRGINIA
NOAA Chart: 12251                                  Latitude:         37° 18.8' N
USGS Quad:  HOPEWELL                               Longitude:        77° 16.2' W


To reach the tidal bench marks from the intersection of Randolph Street and East
Broadway in Hopewell, proceed NE along East Broadway to Brown Avenue, then north
on Brown Avenue to Church Street, then east on Church Street to Water Street. 
The bench marks are in the vicinity of Delta Materials Company near City Point.
The tide gage and staff were on the Regional Enterprises, Inc. dock at 410 Water
Street.


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


                 PRIMARY BENCH MARK STAMPING:  8481 A 1978

MONUMENTATION:           Survey Disk                               VM#:     3465
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set in a concrete monument just north of brick steps leading
up a hill to an old church on the west side of Water Street, 0.05 mile (0.08 km)
south of Church Street, 95.8 feet (29.2 m) SW of power pole #5, 40.2 feet (12.3
m) south of power pole #LP-32-74, 28.1 feet (8.6 m) NW of power pole #LP-41, and
level with the ground.



                         BENCH MARK STAMPING:  H 247 1942

MONUMENTATION:           Survey Disk                               VM#:     3462
AGENCY:                                                            PID#:  GV1644
SETTING CLASSIFICATION:  Concrete Post


The bench mark is at Hopewell, set in the top of a concrete post 80 feet (24 m)
west of the SW corner of the Norfolk and Western Railway station, 76 feet (23 m)
south of the south rail of the east and west track, 20 feet (6 m) west of the
centerline of Hopewell Street, 4.5 feet (1.4 m) west of a pole, and 1.0 foot
(0.3 m) SW of a witness post.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                   PUBLICATION DATE:  04/23/1990
Station ID: 8638481                                SUPERCEDED DATE:   04/21/2003
Name:       CITY POINT, HOPEWELL, JAMES RIVER                 
            VIRGINIA
NOAA Chart: 12251                                  Latitude:         37° 18.8' N
USGS Quad:  HOPEWELL                               Longitude:        77° 16.2' W


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


                         BENCH MARK STAMPING:  NO 6 1971

MONUMENTATION:           Survey Disk                               VM#:     3463
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Cement Footing


The bench mark is set in the cement footing of the Delta Materials Company fence
running parallel to Water Street and the railroad tracks, on the north side of
the southern gate, 59 feet (18 m) SW of the SW leg of a radio transmitting
tower, 9 feet (3 m) NW of the centerline of the ramp entering the Delta
Materials Company property off Water Street, 4.5 feet (1.4 m) east of the east
rail of the railroad tracks, 0.8 foot (0.2 m) SW of the gate post and below a
metal witness post.



                         BENCH MARK STAMPING:  NO 7 1971

MONUMENTATION:           Survey Disk                               VM#:     3464
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Pad


The bench mark is set in a concrete pad on the north side of the Delta Materials
Company yard on Water Street, 111 feet (34 m) north of NW corner of the Delta
Materials building, 79 feet (24 m) west of the NW leg of a batch bin adjacent to
the railroad tracks and a crane on the river bank, 19 feet (6 m) east of the
east rail of the railroad tracks on the edge of Water Street, and 4 feet (1 m)
south of the southern wall of a cinder block shed on the NW corner of the yard.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                   PUBLICATION DATE:  04/23/1990
Station ID: 8638481                                SUPERCEDED DATE:   04/21/2003
Name:       CITY POINT, HOPEWELL, JAMES RIVER                 
            VIRGINIA
NOAA Chart: 12251                                  Latitude:         37° 18.8' N
USGS Quad:  HOPEWELL                               Longitude:        77° 16.2' W


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


                         BENCH MARK STAMPING:  8481 B 1978

MONUMENTATION:           Survey Disk                               VM#:     3466
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set in a concrete monument at the foot of a hill on the west
side of Water Street, 0.15 mile (0.24 km) south of the intersection of Pecan
Avenue and Water Street, 0.1 mile (0.2 km) north of the intersection of Church
and Water Streets, 34.4 feet (10.5 m) NW of power pole #BN 3144, 32.2 feet   
(9.8 m) SW of an unnumbered power pole, 31.4 feet (9.6 m) west of the centerline
of Water Street, and level with the ground.

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

                                                   PUBLICATION DATE:  04/23/1990
Station ID: 8638481                                SUPERCEDED DATE:   04/21/2003
Name:       CITY POINT, HOPEWELL, JAMES RIVER                 
            VIRGINIA
NOAA Chart: 12251                                  Latitude:         37° 18.8' N
USGS Quad:  HOPEWELL                               Longitude:        77° 16.2' W


                            T I D A L   D A T U M S 


Tidal datums at CITY POINT, HOPEWELL, JAMES RIVER based on:

     LENGTH OF SERIES:      12 YEARS
     TIME PERIOD:           1942-1953, 1978
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8638610 HAMPTON ROADS


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

     HIGHEST OBSERVED WATER LEVEL (04/27/1978)         =   6.41
     MEAN HIGHER HIGH WATER                     MHHW   =   2.91
     MEAN HIGH WATER                            MHW    =   2.67
     MEAN TIDE LEVEL                            MTL    =   1.40
   * NATIONAL GEODETIC VERTICAL DATUM           NGVD29 =   0.48
     MEAN LOW WATER                             MLW    =   0.14
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (12/03/1942)         =  -3.80

   * NGVD reference based on elevations published in Quad N37077200, Line 112,
     December 1982. 
North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     8481 A 1978                                15.70     13.03
     H 247 1942                                 48.31     45.64
     NO 6 1971                                  12.16      9.49
     NO 7 1971                                   9.79      7.12
     8481 B 1978                                 9.54      6.87


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

                                                   PUBLICATION DATE:  04/23/1990
Station ID: 8638481                                SUPERCEDED DATE:   04/21/2003
Name:       CITY POINT, HOPEWELL, JAMES RIVER                 
            VIRGINIA
NOAA Chart: 12251                                  Latitude:         37° 18.8' N
USGS Quad:  HOPEWELL                               Longitude:        77° 16.2' 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.

Return to Top
Products available at 8638481 Hopewell, VA