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Bench Mark Sheet for 8466442, MILFORD HARBOR CT

Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8466442                         PUBLICATION DATE:  04/29/2003
Name:       MILFORD HARBOR                                    
            CT
NOAA Chart: 12370                           Latitude:   41° 13.1' N (  41.21830)
USGS Quad:  Milford                         Longitude:  73°  3.3' W ( -73.05500)


To reach the tidal bench marks from the intersection of North Broad and High
Streets in Milford, proceed south on High Street for 0.03 km (0.2 mi) to the end
of the street and the town dock.  The bench marks are along River, North Broad,
and High Streets.  The tide gage and staff were on the SE corner of the town
dock.


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


                 PRIMARY BENCH MARK STAMPING:  6442 A 1987
                         DESIGNATION:          846 6442 A

MONUMENTATION:           Tidal Station disk                    VM#:         2289
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete bulkhead                     OPUS PID:        
LATITUDE:   41° 13.1' N (  41.21830)          LONGITUDE:  73°  3.3' W ( -73.05500)


The primary bench mark is a disk set flush in the NE bulkhead of the town dock,
21.85 m (71.7 ft) NW of the east corner of the dock, 14.17 m (46.5 ft) NE of the
edge of the SW bulkhead of the dock, 0.46 m (1.55 ft) SW of the edge of the NE
bulkhead of the dock, and level with the ground.

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

                                                                                
Station ID: 8466442                         PUBLICATION DATE:  04/29/2003
Name:       MILFORD HARBOR                                    
            CT
NOAA Chart: 12370                           Latitude:   41° 13.1' N (  41.21830)
USGS Quad:  Milford                         Longitude:  73°  3.3' W ( -73.05500)


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


                         BENCH MARK STAMPING:  D 3 1922 ELEV 37.310 FT
                         DESIGNATION:          D 3

MONUMENTATION:           Bench Mark disk                       VM#:         2286
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  LX0896
SETTING CLASSIFICATION:  Railroad head wall                    OPUS PID:        
LATITUDE:   41° 13.4' N (  41.22330)          LONGITUDE:  73°  3.4' W ( -73.05670)


The bench mark is a disk set flush in the top of the west headwall of the
Conrail Railroad bridge over River Street, 4.33 m (14.2 ft) NNE of the north
corner of railroad electric tower #913, 1.62 m (5.3 ft) south of the south rail
of the southernmost Conrail track, 0.82 m (2.7 ft) north of the south end of the
west headwall, and 0.34 m (1.1 ft) below the level of the track.

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

                                                                                
Station ID: 8466442                         PUBLICATION DATE:  04/29/2003
Name:       MILFORD HARBOR                                    
            CT
NOAA Chart: 12370                           Latitude:   41° 13.1' N (  41.21830)
USGS Quad:  Milford                         Longitude:  73°  3.3' W ( -73.05500)


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


                         BENCH MARK STAMPING:  E 3 1922 ELEV 28.632 FT
                         DESIGNATION:          E 3

MONUMENTATION:           Bench Mark disk                       VM#:         2287
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  LX0897
SETTING CLASSIFICATION:  City hall cornerstone                 OPUS PID:        
LATITUDE:   41° 13.6' N (  41.22670)          LONGITUDE:  73°  3.5' W ( -73.05830)


The bench mark is a disk set vertically in the SE cornerstone of Milford City
Hall, 11.43 m (37.5 ft) west of power pole #855 on River Street, 4.54 m (14.9
ft) NW of the SE corner of the concrete porch of City Hall, 0.24 m (0.8 ft)
north of the SE corner of City Hall, and 0.21 m (0.7 ft) above the level of the
concrete porch.

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

                                                                                
Station ID: 8466442                         PUBLICATION DATE:  04/29/2003
Name:       MILFORD HARBOR                                    
            CT
NOAA Chart: 12370                           Latitude:   41° 13.1' N (  41.21830)
USGS Quad:  Milford                         Longitude:  73°  3.3' W ( -73.05500)


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


                         BENCH MARK STAMPING:  D 34 1965
                         DESIGNATION:          D 34

MONUMENTATION:           Bench Mark disk                       VM#:         2288
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  LX0895
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   41° 13.3' N (  41.22170)          LONGITUDE:  73°  3.5' W ( -73.05830)


The bench mark is a disk set flush in the top of the west side of the concrete
foundation for the flagpole at the intersection of High and North Broad Streets,
21 m (69 ft) east of the east curb of High Street, 15.24 m (50.0 ft) north of
the north curb of the eastbound lane of North Broad Street, 14.54 m (47.7 ft)
south of the south curb of the westbound lane of North Broad Street, and 0.37 m
(1.2 ft) above ground level.



                         BENCH MARK STAMPING:  6442 B 1987
                         DESIGNATION:          846 6442  B

MONUMENTATION:           Tidal Station disk                    VM#:         2290
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   41° 13.1' N (  41.21830)          LONGITUDE:  73°  3.3' W ( -73.05500)


The bench mark is a disk set flush in the top of the SW corner of the concrete
foundation of the Milford Boat Works sales office located at 1 High Street,
26.79 m (87.9 ft) ESE of centerline of Helwig Road, 10.45 m (34.3 ft) NNE of the
centerline of High Street, 3.35 m (11.0 ft) WNW of the east face of the concrete
foundation, and 0.18 m (0.6 ft) above ground level.

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

                                                                                
Station ID: 8466442                         PUBLICATION DATE:  04/29/2003
Name:       MILFORD HARBOR                                    
            CT
NOAA Chart: 12370                           Latitude:   41° 13.1' N (  41.21830)
USGS Quad:  Milford                         Longitude:  73°  3.3' W ( -73.05500)


                            T I D A L   D A T U M S 


Tidal datums at MILFORD HARBOR based on:

     LENGTH OF SERIES:      4 MONTHS
     TIME PERIOD:           November 1987 - February 1988
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8467150 BRIDGEPORT, BRIDGEPORT HARBOR


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

     MEAN HIGHER HIGH WATER                     MHHW   =  2.101
     MEAN HIGH WATER                            MHW    =  2.001
     North American Vertical Datum              NAVD88 =  1.110
     MEAN SEA LEVEL                             MSL    =  1.039
     MEAN TIDE LEVEL                            MTL    =  1.038
     MEAN LOW WATER                             MLW    =  0.075
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     6442 A 1987                                 3.063    1.062
     D 3 1922 ELEV 37.310 FT                    12.152   10.151
     E 3 1922 ELEV 28.632 FT                     9.507    7.506
     D 34 1965                                  10.648    8.647
     6442 B 1987                                 3.961    1.960


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

                                                                                
Station ID: 8466442                         PUBLICATION DATE:  04/29/2003
Name:       MILFORD HARBOR                                    
            CT
NOAA Chart: 12370                           Latitude:   41° 13.1' N (  41.21830)
USGS Quad:  Milford                         Longitude:  73°  3.3' W ( -73.05500)


                             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 8466442 MILFORD HARBOR, CT

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