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Bench Mark Sheet for 9445478, UNION, HOOD CANAL WA

Superseded Epoch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Small blue map location marker Unpublished bench mark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  5

                                                                                
Station ID: 9445478                         PUBLICATION DATE:  08/09/2004
Name:       UNION, HOOD CANAL                                 
            WA
NOAA Chart: 18476                           Latitude:   47° 21.5' N (  47.35830)
USGS Quad:  POTLATCH                        Longitude: 123°  5.9' W (-123.09800)


To reach the tidal bench marks from the Post Office in Union, proceed west on
State Route 106 for 100 m (328 ft) to the Hood Canal Marina building.  The bench
marks are located along State Route 106.  The tide gage and staff were located
on the pier east of the Hood Canal Marina building.


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


                 PRIMARY BENCH MARK STAMPING:  3 1935
                         DESIGNATION:          944 5478 TIDAL 3

MONUMENTATION:           Tidal Station disk                    VM#:         9060
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  SY1271
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID:        
LATITUDE:   47° 21.4' N (  47.35670)          LONGITUDE: 123°  6.3' W (-123.10500)


The primary bench mark is a disk set in the concrete slab at the southernmost
corner of the Mobile Service station on the north side of State Highway 106, 0.3
km (0.2 mi) west of the post office, 120 m (394 ft) west of the remains of the
Masonic Hall, 13 m (42 ft) north of the centerline of State Highway 106, 0.76 m
(2.5 ft) west of the SE corner of the building, and  0.15 m (0.5 ft) south of
the south face of the building.

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

                                                                                
Station ID: 9445478                         PUBLICATION DATE:  08/09/2004
Name:       UNION, HOOD CANAL                                 
            WA
NOAA Chart: 18476                           Latitude:   47° 21.5' N (  47.35830)
USGS Quad:  POTLATCH                        Longitude: 123°  5.9' W (-123.09800)


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


                         BENCH MARK STAMPING:  4 1935
                         DESIGNATION:          944 5478 TIDAL 4

MONUMENTATION:           Tidal Station disk                    VM#:         9061
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)`                                IDB PID#:  SY1274
SETTING CLASSIFICATION:  Retaining wall                        OPUS PID:        
LATITUDE:   47° 21.4' N (  47.35670)          LONGITUDE: 123°  6.1' W (-123.10200)


The bench mark is a disk set vertically in the north face of a concrete
retaining wall in front of a private home, 177 m (580 ft) west of the post
office, 25 m (81 ft) SE of the SE corner of the remains of the Masonic Hall, 7 m
(22 ft) south of the centerline of State Highway 106, 1 m (3 ft) east of the
west end of the retaining wall, and 0.3 m (1 ft) above the level of the highway.



                         BENCH MARK STAMPING:  BM 1 1972
                         DESIGNATION:          944 5478 TIDAL 1

MONUMENTATION:           Tidal Station disk                    VM#:         9063
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  SY1272
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID:        
LATITUDE:   47° 21.4' N (  47.35670)          LONGITUDE: 123°  6.3' W (-123.10500)


The bench mark is a disk set flush in the center of the north end of a 5 x 8 m
(17 x 27 ft) concrete slab that served as the floor to an old firehouse adjacent
to and east of the Mobile Gas Station, 0.3 km (0.2 mi) west of the post office,
29 m (94 ft) north of the centerline of State Highway 106, 23 m (74 ft) NW of
power pole U 105 bearing a transformer and a light, 21.76 m (71.4 ft) NE of
bench mark 3 1935, 1.83 m (6.0 ft) east of the NW corner of the concrete slab,
and 1 m (2 ft) below the level of the highway.

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

                                                                                
Station ID: 9445478                         PUBLICATION DATE:  08/09/2004
Name:       UNION, HOOD CANAL                                 
            WA
NOAA Chart: 18476                           Latitude:   47° 21.5' N (  47.35830)
USGS Quad:  POTLATCH                        Longitude: 123°  5.9' W (-123.09800)


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


                         BENCH MARK STAMPING:  NO 7 1973
                         DESIGNATION:          944 5478 TIDAL 7

MONUMENTATION:           Tidal Station disk                    VM#:         9064
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID:        
LATITUDE:   47° 21.5' N (  47.35830)          LONGITUDE: 123°  5.9' W (-123.09800)


The bench mark is a disk set in concrete slab (walkway) around the Hood Canal
Marina building, next to the building and at the SE corner of the door to the
men's restroom, 5 m (16 ft) back and 2 m (6 ft) over from the corner of the
concrete slab.

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

                                                                                
Station ID: 9445478                         PUBLICATION DATE:  08/09/2004
Name:       UNION, HOOD CANAL                                 
            WA
NOAA Chart: 18476                           Latitude:   47° 21.5' N (  47.35830)
USGS Quad:  POTLATCH                        Longitude: 123°  5.9' W (-123.09800)


                            T I D A L   D A T U M S 


Tidal datums at UNION, HOOD CANAL based on:

     LENGTH OF SERIES:      4 MONTHS
     TIME PERIOD:           June 1977 - September 1977
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9447130 SEATTLE, PUGET SOUND


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

     MEAN HIGHER HIGH WATER                     MHHW   =  3.613
     MEAN HIGH WATER                            MHW    =  3.312
     MEAN SEA LEVEL                             MSL    =  2.122
     MEAN TIDE LEVEL                            MTL    =  2.115
     MEAN LOW WATER                             MLW    =  0.917
     North American Vertical Datum              NAVD88 =  0.865
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     3 1935                                      5.605    2.293
     4 1935                                      6.483    3.171
     BM 1 1972                                   4.741    1.429
     NO 7 1973                                   4.681    1.369


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

                                                                                
Station ID: 9445478                         PUBLICATION DATE:  08/09/2004
Name:       UNION, HOOD CANAL                                 
            WA
NOAA Chart: 18476                           Latitude:   47° 21.5' N (  47.35830)
USGS Quad:  POTLATCH                        Longitude: 123°  5.9' W (-123.09800)


                             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 9445478 UNION, HOOD CANAL, WA

Revised: 08/08/2018
NOAA / National Ocean Service
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