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Bench Mark Sheet for 8461392, NORWICH, THAMES RIVER 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8461392                         PUBLICATION DATE:  04/29/2003
Name:       NORWICH, THAMES RIVER                             
            CT
NOAA Chart: 12372                           Latitude:   41° 31.4' N (  41.52330)
USGS Quad:  Norwich                         Longitude:  72°  4.7' W ( -72.07830)


To reach the tidal bench marks from the intersection of Shetucket and Market
Streets on the south side of Norwich, turn into the parking lot of the city park
and town dock.  The bench marks are along Shetucket, West Main, and Thames
Streets.  The tide gage and staff were located at 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:  NO 2 1967
                         DESIGNATION:          846 1392 TIDAL 2

MONUMENTATION:           Tidal Station disk                    VM#:         2225
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete bulkhead                     OPUS PID:        
LATITUDE:   41° 31.4' N (  41.52330)          LONGITUDE:  72°  4.7' W ( -72.07830)


The primary bench mark is a disk set flush in the SE end of the concrete
bulkhead of the town dock, 27.55 m (90.4 ft) NW of a flagpole in the park, 5.91
m (19.4 ft) ENE of the SE corner of the town dock, and 0.82 m (2.7 ft) NNW of
the SE edge of the bulkhead.

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

                                                                                
Station ID: 8461392                         PUBLICATION DATE:  04/29/2003
Name:       NORWICH, THAMES RIVER                             
            CT
NOAA Chart: 12372                           Latitude:   41° 31.4' N (  41.52330)
USGS Quad:  Norwich                         Longitude:  72°  4.7' W ( -72.07830)


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


                         BENCH MARK STAMPING:  NO 3 1967
                         DESIGNATION:          846 1392 TIDAL 3

MONUMENTATION:           Tidal Station disk                    VM#:         2226
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete bulkhead                     OPUS PID:        
LATITUDE:   41° 31.4' N (  41.52330)          LONGITUDE:  72°  4.7' W ( -72.07830)


The bench mark is a disk set flush in the NW end of the concrete bulkhead of the
town dock, 32.34 m (106.1 ft) WSW of a power pole at the intersection of
Shetucket and Market Streets, 30.51 m (100.1 ft) NNW of bench mark No 2 1967,
5.67 m (18.6 ft) ENE of the NE corner of the town dock, and 1.13 m (3.7 ft) SSE
of the NW face of the concrete base of a light pole.

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

                                                                                
Station ID: 8461392                         PUBLICATION DATE:  04/29/2003
Name:       NORWICH, THAMES RIVER                             
            CT
NOAA Chart: 12372                           Latitude:   41° 31.4' N (  41.52330)
USGS Quad:  Norwich                         Longitude:  72°  4.7' W ( -72.07830)


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


                         BENCH MARK STAMPING:  W 90 1986
                         DESIGNATION:          W 90

MONUMENTATION:           Flange-encased Rod                    VM#:         2227
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  LX3226
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   41° 31.4' N (  41.52330)          LONGITUDE:  72°  4.8' W ( -72.08000)


The bench mark is a flange-encased rod set in a landscaped area at the north end
of the municipal parking lot between Shetucket and Water Streets, 23.77 m (78.0
ft) SE of a sign for Slater Memorial Museum, 13 m (43 ft) NE of the east curb of
Shetucket Street, 8.11 m (26.6 ft) SE of a sign that reads Do Not Enter, 6.61 m
(21.7 ft) SW of utility pole #W222, 6.13 m (20.1 ft) SW of the west curb of
Water Street, and 0.46 m (1.5 ft) NE of a circular parking curb at the north end
of the lot.  The datum point is the top of a stainless steel rod driven 2.1 m (7
ft), and encased in a 5-inch flange with logo cap.

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

                                                                                
Station ID: 8461392                         PUBLICATION DATE:  04/29/2003
Name:       NORWICH, THAMES RIVER                             
            CT
NOAA Chart: 12372                           Latitude:   41° 31.4' N (  41.52330)
USGS Quad:  Norwich                         Longitude:  72°  4.7' W ( -72.07830)


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


                         BENCH MARK STAMPING:  M 97 1986
                         DESIGNATION:          M 97

MONUMENTATION:           Flange-encased Rod                    VM#:         2228
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  LX3397
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID#: LX3397
LATITUDE:   41° 31.2' N (  41.52000)          LONGITUDE:  72°  4.8' W ( -72.08000)


The bench mark is a flange-encased rod set in the grass median between the 
sidewalk and the parking lot at the entrance to Norwich Police Department on
Thames Street, 13.17 m (43.2 ft) north of power pole #T113, 7.38 m (24.2 ft) NE
of the centerline of Thames Street, 5.49 m (18.0 ft) NNE of the centerline of
the entrance drive to the police station, and 1.01 m (3.3 ft) NE of the NE curb
of the sidewalk.  The datum point is the top of a stainless steel rod driven 3.4
m (11 ft), and encased in a 5-inch flange with logo cap.



                         BENCH MARK STAMPING:  1392 A 1989
                         DESIGNATION:          846 1392 A

MONUMENTATION:           Tidal Station disk                    VM#:         2229
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete abutment                     OPUS PID:        
LATITUDE:   41° 31.4' N (  41.52330)          LONGITUDE:  72°  4.7' W ( -72.07830)


The bench mark is a disk set flush in the SE corner of the NE concrete abutment
for the West Main Street bridge over the Connecticut-Vermont Railroad tracks
which run parallel to Thames Street, ENE of the intersection of West Main and
Thames Streets, 46 m (152 ft) WSW of the west wall of the law offices at No. 74
West Main Street, 5 m (16 ft) SSE of the south curb of West Main Street, and
1.13 m (3.7 ft) ENE of the SW face of the abutment.

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

                                                                                
Station ID: 8461392                         PUBLICATION DATE:  04/29/2003
Name:       NORWICH, THAMES RIVER                             
            CT
NOAA Chart: 12372                           Latitude:   41° 31.4' N (  41.52330)
USGS Quad:  Norwich                         Longitude:  72°  4.7' W ( -72.07830)


                            T I D A L   D A T U M S 


Tidal datums at NORWICH, THAMES RIVER based on:

     LENGTH OF SERIES:      4 MONTHS
     TIME PERIOD:           July 1989 - October 1989
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8461490 NEW LONDON, THAMES RIVER


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.092
     MEAN HIGH WATER                            MHW    =  0.994
     North American Vertical Datum              NAVD88 =  0.603
     MEAN SEA LEVEL                             MSL    =  0.568
     MEAN TIDE LEVEL                            MTL    =  0.533
     MEAN LOW WATER                             MLW    =  0.071
     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 2 1967                                   2.091    1.097
     NO 3 1967                                   2.087    1.093
     W 90 1986                                   5.280    4.286
     M 97 1986                                   9.759    8.765
     1392 A 1989                                 5.914    4.920


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

                                                                                
Station ID: 8461392                         PUBLICATION DATE:  04/29/2003
Name:       NORWICH, THAMES RIVER                             
            CT
NOAA Chart: 12372                           Latitude:   41° 31.4' N (  41.52330)
USGS Quad:  Norwich                         Longitude:  72°  4.7' W ( -72.07830)


                             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 8461392 NORWICH, THAMES RIVER, CT

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