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Superseded Bench Mark Sheet for 8551910, Reedy Point DE

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  6

                                                   PUBLICATION DATE:  04/02/1992
Station ID: 8551910                                SUPERCEDED DATE:   04/21/2003
Name:       REEDY POINT, CHESAPEAKE AND DELAWARE CANAL        
            DELAWARE
NOAA Chart: 12277                                  Latitude:         39° 33.5' N
USGS Quad:  DELAWARE CITY                          Longitude:        75° 34.4' W


To reach the tidal bench marks from Delaware City, proceed south on State
Highway 9 and the bridge over Delaware City Branch Channel to the Reedy Point
bridge over Chesapeake and Delaware Canal.  The bench marks are along the clay
road on the west parallel to State Highway 9, on the east-west dirt road south
of the canal, and south along State Highway 9.  The tide gauge and staff are on
the Corps of Engineers T-pier, east of the bridge and on the south side of the
canal.


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


                 PRIMARY BENCH MARK STAMPING:   

MONUMENTATION:                                                     VM#:      383
AGENCY:                                                            PID#:  JU2187
SETTING CLASSIFICATION:  






                         BENCH MARK STAMPING:  1910 B 1979

MONUMENTATION:           Survey Disk                               VM#:      376
AGENCY:                                                            PID#:  JU2189
SETTING CLASSIFICATION:  Stainless Steel Rod


The primary bench mark is east of the Reedy Point bridge over Chesapeake and
Delaware Canal, on the south side of the east-west dirt road south of the canal,
424 feet (129.2 m) WSW of the SW corner of the pier, 39.6 feet (12.1 m) south of
a utility pole with light attached, and 21.0 feet (6.4 m) south of the
centerline of the road.  The bench mark is 0.5 foot (0.2 m) above the ground,
crimped to a stainless steel rod driven 32.0 feet (9.8 m) 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  6

                                                   PUBLICATION DATE:  04/02/1992
Station ID: 8551910                                SUPERCEDED DATE:   04/21/2003
Name:       REEDY POINT, CHESAPEAKE AND DELAWARE CANAL        
            DELAWARE
NOAA Chart: 12277                                  Latitude:         39° 33.5' N
USGS Quad:  DELAWARE CITY                          Longitude:        75° 34.4' W


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


                         BENCH MARK STAMPING:  PORT PENN NO 1 1933

MONUMENTATION:           Survey Disk                               VM#:      378
AGENCY:                                                            PID#:  JU1809
SETTING CLASSIFICATION:  Concrete Culvert


The bench mark is set in a concrete culvert headwall about 2.2 miles (3.5 km)
south of Chesapeake and Delaware Canal, 1.1 miles (1.8 km) north along State
Highway 9 from the T-intersection of Market Street at the west end of Port Penn,
at the intersection with a farm road leading west, 40.5 feet (12.3 m) WNW and
across the highway from utility pole #DP&L3, 19.5 feet (5.9 m) west of the
centerline of the highway, 7.0 feet (2.1 m) north of the centerline of the farm
road, and 0.5 foot (0.2 m) above the highway surface.



                         BENCH MARK STAMPING:  1910 C 1979

MONUMENTATION:           Survey Disk                               VM#:      381
AGENCY:                                                            PID#:  JU2188
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is east of the Reedy Point bridge over Chesapeake and Delaware
Canal, on the south side of the east-west dirt road south of the canal, 0.2 mile
(0.3 km) west of the pier, 45.0 feet (13.7 m) south of utility pole #85 with
light attached, and 22.0 feet (6.7 m) south of the centerline of the dirt road. 
The bench mark is 0.5 foot (0.2 m) above the ground, crimped to a stainless
steel rod driven 30.0 feet (9.1 m), 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  6

                                                   PUBLICATION DATE:  04/02/1992
Station ID: 8551910                                SUPERCEDED DATE:   04/21/2003
Name:       REEDY POINT, CHESAPEAKE AND DELAWARE CANAL        
            DELAWARE
NOAA Chart: 12277                                  Latitude:         39° 33.5' N
USGS Quad:  DELAWARE CITY                          Longitude:        75° 34.4' W


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


                         BENCH MARK STAMPING:  1910 G 1982

MONUMENTATION:           Survey Disk                               VM#:      382
AGENCY:                                                            PID#:  AJ6314
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is along the dirt road on the south side of Chesapeake and
Delaware Canal, on the extended centerline of the pier, 85.5 feet (26.1 m) SW of
a utility pole with light attached on the east side of the pier, 50.0 feet (15.2
m) south of the   south end of the pier, 23.0 feet (7.0 m) south of the
centerline   of the dirt road, and 3.4 feet (1.0 m) north of a steel witness
post.  The bench mark is crimped to a stainless steel rod driven   an
unspecified depth to refusal, and encased in a PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  PORT PENN NO 2 1933

MONUMENTATION:           Survey Disk                               VM#:      384
AGENCY:                                                            PID#:  JU1808
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set in a concrete monument about 2.2 miles    (3.5 km) south
of Chesapeake and Delaware Canal, 1.1 miles     (1.8 km) north along State
Highway 9 from the T-intersection of Market Street at the west end of Port Penn,
217.0 feet (66.1 m) north of Bench Mark PORT PENN NO 1 1933, 148.0 feet (45.1 m)
SW and across the highway from utility pole #DP&L4, 38.3 feet    (11.7 m) west
of the centerline of the highway, and at ground level.

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

                                                   PUBLICATION DATE:  04/02/1992
Station ID: 8551910                                SUPERCEDED DATE:   04/21/2003
Name:       REEDY POINT, CHESAPEAKE AND DELAWARE CANAL        
            DELAWARE
NOAA Chart: 12277                                  Latitude:         39° 33.5' N
USGS Quad:  DELAWARE CITY                          Longitude:        75° 34.4' W


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


                         BENCH MARK STAMPING:  RP 3 1975

MONUMENTATION:           Survey Disk                               VM#:      385
AGENCY:                                                            PID#:  JU2186
SETTING CLASSIFICATION:  Concrete Culvert


The bench mark is set in a concrete culvert headwall on the    south side of
Chesapeake and Delaware Canal, along the clay   road (Road 2) parallel to and on
the west side of State Highway 9, 483.0 feet (147.2 m) south of the canal, 164.4
feet (50.1 m) west of bridge pier #R38W, and 18.0 feet (5.5 m) east of the
centerline of the road.



                         BENCH MARK STAMPING:  RP 5 1975

MONUMENTATION:           Survey Disk                               VM#:      386
AGENCY:                                                            PID#:  JU2185
SETTING CLASSIFICATION:  Concrete Culvert


The bench mark is set in a concrete culvert headwall on the   south side of
Chesapeake and Delaware Canal, along the clay    road (Road 2) parallel to and
on the west side of State Highway 9, 75.5 feet (23.0 m) NW of bridge pier #R53W,
67.0 feet (20.4 m) SW of bridge pier #R52W, 22.3 feet (6.8 m) SE of utility pole
#DP&L 17, and 22.0 feet (6.7 m) west of the centerline of the road.



                         BENCH MARK STAMPING:  R 72 W

MONUMENTATION:           Survey Disk                               VM#:    12414
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is on the west side of the south approach to the Reedy Point
bridge over Chesapeake and Delaware Canal, 397.6 feet (121.2 m) NE of the
junction of State Highway 9 and Road 417,   195.6 feet (59.6 m) south of the
south end of the bridge, 23.5 feet  (7.2 m) SW of the centerline of State
Highway 9, 0.8 foot (0.2 m) west of the curb, and level with the curb.

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

                                                   PUBLICATION DATE:  04/02/1992
Station ID: 8551910                                SUPERCEDED DATE:   04/21/2003
Name:       REEDY POINT, CHESAPEAKE AND DELAWARE CANAL        
            DELAWARE
NOAA Chart: 12277                                  Latitude:         39° 33.5' N
USGS Quad:  DELAWARE CITY                          Longitude:        75° 34.4' W


                            T I D A L   D A T U M S 


Tidal datums at REEDY POINT, CHESAPEAKE AND DELAWARE CANAL based on:

     LENGTH OF SERIES:      106 MONTHS
     TIME PERIOD:           1982-1990
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8557380 LEWES


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

     HIGHEST OBSERVED WATER LEVEL (10/25/1980)         =   9.19
     MEAN HIGHER HIGH WATER                     MHHW   =   5.98
     MEAN HIGH WATER                            MHW    =   5.68
     MEAN TIDE LEVEL                            MTL    =   2.93
   * NATIONAL GEODETIC VERTICAL DATUM           NGVD29 =   2.51
     MEAN LOW WATER                             MLW    =   0.18
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (04/07/1982)         =  -3.70

   * NGVD reference based on adjustment of 1972 and NOS levels of 1990. 
North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     0                                           0.00      0.00
     1910 B 1979                                11.05      5.37
     PORT PENN NO 1 1933                        11.25      5.57
     1910 C 1979                                10.65      4.97
     1910 G 1982                                 8.17      2.49
     PORT PENN NO 2 1933                        12.94      7.26
     RP 3 1975                                   6.46      0.78
     RP 5 1975                                   7.94      2.26
     R 72 W                                     19.68     14.00


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

                                                   PUBLICATION DATE:  04/02/1992
Station ID: 8551910                                SUPERCEDED DATE:   04/21/2003
Name:       REEDY POINT, CHESAPEAKE AND DELAWARE CANAL        
            DELAWARE
NOAA Chart: 12277                                  Latitude:         39° 33.5' N
USGS Quad:  DELAWARE CITY                          Longitude:        75° 34.4' 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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Revised: 08/08/2018
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