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Bench Mark Sheet for 8573927, Chesapeake City MD

Superseded Epoch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Small blue map location marker Unpublished bench mark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  8

                                                                                
Station ID: 8573927                         PUBLICATION DATE:  09/24/2012
Name:       CHESAPEAKE CITY                                   
            MD
NOAA Chart: 12277                           Latitude:   39° 31.6' N (  39.52670)
USGS Quad:  ELKTON                          Longitude:  75° 48.6' W ( -75.81000)


To reach the tidal bench marks from the south end of the State Highway 213
bridge over the Chesapeake and Delaware (C & D) Canal at Chesapeake City,
proceed south on State Highway 213 for 0.89 km (0.55 mi) and take the South
Chesapeake City exit, continue 0.3 km (0.2 mi) NNE (towards canal) from the base
of the exit to a signpost directing the way to the C & D Canal Museum, turn
right and follow the curving road for 0.2 km (0.1 mi) to a T-intersection, turn
right and follow the curving road for 0.6 km (0.4 mi) to a T-intersection, turn
left and proceed 0.08 km (0.05 mi) to the main gate of the U.S. Army Corps of
Engineers (COE) facility and the C & D Canal Museum. The bench marks are located
on the COE grounds. The tide gage is located at the west corner of the bulkhead
at the west end of the COE grounds.


                         T I D A L   B E N C H   M A R K S
                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  8

                                                                                
Station ID: 8573927                         PUBLICATION DATE:  09/24/2012
Name:       CHESAPEAKE CITY                                   
            MD
NOAA Chart: 12277                           Latitude:   39° 31.6' N (  39.52670)
USGS Quad:  ELKTON                          Longitude:  75° 48.6' W ( -75.81000)


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


                 PRIMARY BENCH MARK STAMPING:  U 2 1931 6.834
                         DESIGNATION:          U 2

MONUMENTATION:           Bench Mark disk                       VM#:         3167
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  JU1833
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   39° 31.6' N (  39.52717)          LONGITUDE:  75° 48.4' W ( -75.80728)


The primary bench mark is a disk set in a 0.24 m (0.8 ft) square concrete
monument located south of the COE administration building, 14.57 m (47.8 ft)
south of the west concrete wall for the steps leading to the basement of the
administration building, 10.27 m (33.7 ft) north of the centerline of the main
road, 8.56 m (28.1 ft) west of the west edge of a sidewalk leading to the
administration building, and 0.15 m (0.5 ft) above the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  8

                                                                                
Station ID: 8573927                         PUBLICATION DATE:  09/24/2012
Name:       CHESAPEAKE CITY                                   
            MD
NOAA Chart: 12277                           Latitude:   39° 31.6' N (  39.52670)
USGS Quad:  ELKTON                          Longitude:  75° 48.6' W ( -75.81000)


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


                         BENCH MARK STAMPING:  NO 1 1938
                         DESIGNATION:          TIDAL 1 STA 62

MONUMENTATION:           Tidal Station disk                    VM#:         3168
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  JU1835
SETTING CLASSIFICATION:  Concrete walkway                      OPUS PID:        
LATITUDE:   39° 31.6' N (  39.52714)          LONGITUDE:  75° 48.6' W ( -75.80961)


The bench mark is a disk set in a concrete walkway located at the NW corner of a
single story white brick building (Bridge Repair Shop) near the west end of the
COE grounds, 20.48 m (67.2 ft) south of the centerline of the main road, 0.52 m
(1.7 ft) north of the north wall of the brick building, and 0.46 m (1.5 ft) east
of the west wall of the brick building.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  8

                                                                                
Station ID: 8573927                         PUBLICATION DATE:  09/24/2012
Name:       CHESAPEAKE CITY                                   
            MD
NOAA Chart: 12277                           Latitude:   39° 31.6' N (  39.52670)
USGS Quad:  ELKTON                          Longitude:  75° 48.6' W ( -75.81000)


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


                         BENCH MARK STAMPING:  NO 2 1938
                         DESIGNATION:          TIDAL 2 STA 62

MONUMENTATION:           Tidal Station disk                    VM#:         3169
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  JU1834
SETTING CLASSIFICATION:  Stone retaining wall                  OPUS PID:        
LATITUDE:   39° 31.6' N (  39.52742)          LONGITUDE:  75° 48.5' W ( -75.80819)


The bench mark is a disk set in the top of a stone retaining wall located around
the Bethel Bridge Lighthouse, 73.71 m (241.8 ft) west of the west face of the
COE administration building, 16.32 m (53.5 ft) north of the centerline of the
road on base, 9.00 m (29.5 ft) south of the rip-rap bulkhead of the C & D Canal,
and 3.10 m (10.2 ft) east of the west end of the stone retaining wall around the
Bethel Bridge.



                         BENCH MARK STAMPING:  NO 3 1972
                         DESIGNATION:          857 3927 TIDAL 3

MONUMENTATION:           Tidal Station disk                    VM#:         3170
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   39° 31.6' N (  39.52717)          LONGITUDE:  75° 48.5' W ( -75.80781)


The bench mark is a disk set in the NW concrete pump well located SW of the COE
administration building, 5.94 m (19.5 ft) north of the NW corner of a ventilator
shaft, 4.63 m (15.2 ft) south of the centerline of the main road, and 4.45 m
(14.6 ft) SW of the southernmost of two steel gate posts for a road gate.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  8

                                                                                
Station ID: 8573927                         PUBLICATION DATE:  09/24/2012
Name:       CHESAPEAKE CITY                                   
            MD
NOAA Chart: 12277                           Latitude:   39° 31.6' N (  39.52670)
USGS Quad:  ELKTON                          Longitude:  75° 48.6' W ( -75.81000)


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


                         BENCH MARK STAMPING:  NO 4 1972
                         DESIGNATION:          857 3927 TIDAL 4

MONUMENTATION:           Tidal Station disk                    VM#:         3171
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Antenna tower foundation              OPUS PID:        
LATITUDE:   39° 31.6' N (  39.52744)          LONGITUDE:  75° 48.4' W ( -75.80736)


The bench mark is a disk set in the concrete foundation of the westernmost leg
of the three legs of a 49 m (161 ft) high steel radio antenna, 40.57 m (133.1
ft) north of the centerline of the main road, 16.73 m (54.9 ft) SE of the
outside NW corner of the reinforced  bulkhead on the south shore of the C & D
Canal, and 8.87 m (29.1 ft) SW of the NW corner of the C & D Canal observation
addition to the two story COE administration building.



                         BENCH MARK STAMPING:  3927 B 1982
                         DESIGNATION:          857 3927 B

MONUMENTATION:           Tidal Station disk                    VM#:         3173
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   39° 31.6' N (  39.52653)          LONGITUDE:  75° 48.4' W ( -75.80706)


The bench mark is a disk located SE of the COE administration building, 34.59 m
(113.5 ft) SW of the centerline of the main road, 10.58 m (34.7 ft) NNE of the
center of the southernmost section of a dock on the north shore of the harbor,
4.48 m (14.7 ft) SE of the concrete walkway leading to the dock, and 0.61 m (2.0
ft) east of the easternmost pole supporting electrical boxes. The bench mark is
set 0.33 m (1.1 ft) below ground, crimped to a galvanized steel rod driven 7 m
(24 ft) to refusal, and encased in a 4-inch PVC pipe with cap and concrete
kickblock.  (Note - a large wrench is needed to remove the cap.)

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  8

                                                                                
Station ID: 8573927                         PUBLICATION DATE:  09/24/2012
Name:       CHESAPEAKE CITY                                   
            MD
NOAA Chart: 12277                           Latitude:   39° 31.6' N (  39.52670)
USGS Quad:  ELKTON                          Longitude:  75° 48.6' W ( -75.81000)


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


                         BENCH MARK STAMPING:  3927 C 1982
                         DESIGNATION:          857 3927 C

MONUMENTATION:           Tidal Station disk                    VM#:         3174
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   39° 31.5' N (  39.52567)          LONGITUDE:  75° 48.4' W ( -75.80594)


The bench mark is a disk located near the SE end of the COE facility, just east
of the main gate, 18.78 m (61.6 ft) SW of the centerline of the main road
leading to the COE facility, 14.48 m (47.5 ft) SE of the easternmost picnic
table, 8.99 m (29.5 ft) NW of the centerline of State Highway 286, and 0.61 m
(2.0 ft) NW of utility pole 17318. The bench mark is set 0.09 m (0.3 ft) below
ground, crimped to a galvanized steel rod driven 5 m (16 ft) to refusal, and
encased in a 4-inch PVC pipe with cap and a concrete kickblock.  (Note - A large
wrench is needed to remove the cap.)

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  8

                                                                                
Station ID: 8573927                         PUBLICATION DATE:  09/24/2012
Name:       CHESAPEAKE CITY                                   
            MD
NOAA Chart: 12277                           Latitude:   39° 31.6' N (  39.52670)
USGS Quad:  ELKTON                          Longitude:  75° 48.6' W ( -75.81000)


                            T I D A L   D A T U M S 


Tidal datums at CHESAPEAKE CITY based on:

     LENGTH OF SERIES:      10 YEARS
     TIME PERIOD:           May 1981 - April 1983 and April 2004 - March 2012
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8551910 REEDY POINT, C&D CANAL


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

     HIGHEST OBSERVED WATER LEVEL (09/19/2003)         =  2.643
     MEAN HIGHER HIGH WATER                     MHHW   =  0.979
     MEAN HIGH WATER                            MHW    =  0.920
     MEAN TIDE LEVEL                            MTL    =  0.493
     MEAN SEA LEVEL                             MSL    =  0.475
     MEAN LOW WATER                             MLW    =  0.066
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (04/05/1975)         = -1.134

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     U 2 1931 6.834                              2.201    1.281
     NO 1 1938                                   2.285    1.365
     NO 2 1938                                   3.388    2.468
     NO 3 1972                                   2.428    1.508
     NO 4 1972                                   4.292    3.372
     3927 B 1982                                 1.197    0.277
     3927 C 1982                                 1.442    0.522


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  8 of  8

                                                                                
Station ID: 8573927                         PUBLICATION DATE:  09/24/2012
Name:       CHESAPEAKE CITY                                   
            MD
NOAA Chart: 12277                           Latitude:   39° 31.6' N (  39.52670)
USGS Quad:  ELKTON                          Longitude:  75° 48.6' W ( -75.81000)


                             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 8573927 Chesapeake City, MD

Revised: 10/15/2013
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services