U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
Station ID: 9454240 PUBLICATION DATE: 09/30/2011
Name: VALDEZ, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16708 Latitude: 61° 7.5' N ( 61.12500)
USGS Quad: VALDEZ A-7 Longitude: 146° 21.7' W (-146.36200)
To reach the tidal bench marks from Valdez as Richardson Highway turns into Egan
Drive, continue west on Egan Drive for two blocks, turn south (left) onto
Hazelet Avenue, follow Hazelet to end, turn west (right) and follow signs to
ferry terminal. The bench marks were in the general vicinity of the ferry
terminal. The tide gauge is located on west end of the pier in a standard 4' X
6' fiberglass tide house.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 21 1966
DESIGNATION: 945 4240 TIDAL 21
MONUMENTATION: Tidal Station disk VM#: 1248
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID#: BBFQ81
LATITUDE: 61° 7.5' N ( 61.12542) LONGITUDE: 146° 21.4' W (-146.35636)
The primary bench mark is a disk located at the SW corner of the intersection of
Fidalgo Drive and Breakwater Street, 53.20 m (174.5 ft) NE of the NE corner of
the Alyeska Company warehouse, 16.20 m (53.15 ft) SE from the SE corner of the
City of Valdez Comfort Station, 2.00 m (6.6 ft) NW from fire hydrant, 0.60 m
(2.0 ft) west from a standard metal witness post and 0.30 m (1.0 ft) east from
telephone pole #220452. The bench mark is a disk, crimped to the top of a
copper-clad rod, driven to an unspecified depth, and encased in a 6" pipe with
aluminum cover which projects 0.20 m (0.6 ft) above ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 9454240 PUBLICATION DATE: 09/30/2011
Name: VALDEZ, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16708 Latitude: 61° 7.5' N ( 61.12500)
USGS Quad: VALDEZ A-7 Longitude: 146° 21.7' W (-146.36200)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: WAREHOUSE 1966
DESIGNATION: 945 4240 WAREHOUSE
ALIAS: 22 USE
MONUMENTATION: Survey disk VM#: 1254
AGENCY: US Army Corps of Engineers (USE) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 61° 7.5' N ( 61.12514) LONGITUDE: 146° 21.6' W (-146.36072)
The bench mark is a disk set flush in concrete edge on the east side of the
warehouse foundation, at the entrance to the southern-most roll up door on the
east side of the building, 20.0 m (65.6 ft) west of the centerline of Hazelet
Avenue, 13.70 m (44.9 ft) north of the SE corner of the warehouse that parallels
the road to the dock, 3.10 m (10.2 ft) south of the north edge of the first door
north of the south end of the warehouse, and 0.91 m (3.0 ft) above ground level.
BENCH MARK STAMPING: 4240 K 1977
DESIGNATION: 945 4240 K
MONUMENTATION: Tidal Station disk VM#: 1256
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete slab OPUS PID#: BBFQ80
LATITUDE: 61° 7.7' N ( 61.12831) LONGITUDE: 146° 21.3' W (-146.35531)
The bench mark is a disk set in a semicircular concrete slab (adjoining the main
sidewalk) used to support a flagpole, 32 m (105 ft) east of the centerline of
Tatiter Street, 17.60 m (57.7 ft) north of the centerline of Galena Street, 8.40
m (27.6 ft) north of the south termination of the sidewalk, 5.40 m (17.7 ft)
south of the SW edge of the Post Office Building, 4.10 m (13.5 ft) east of the
west edge of the north-south sidewalk leading to the west building entrance, and
0.80 m (2.6 ft) south of the center of the flagpole.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 9454240 PUBLICATION DATE: 09/30/2011
Name: VALDEZ, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16708 Latitude: 61° 7.5' N ( 61.12500)
USGS Quad: VALDEZ A-7 Longitude: 146° 21.7' W (-146.36200)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4240 L 1978
DESIGNATION: 945 4240 L
MONUMENTATION: Tidal Station disk VM#: 1257
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Flagpole foundation OPUS PID:
LATITUDE: 61° 7.6' N ( 61.12658) LONGITUDE: 146° 21.2' W (-146.35408)
The bench mark is a disk set flush in the concrete base of a flagpole at the
U.S. Coast Guard Vessel Traffic System Building in Valdez, located near the
north end of the north-south running concrete median strip in the center of the
asphalt parking lot for the Vessel Traffic Center, 26.0 m (85.3 ft) north of the
center of the northern wall of a small open service building located at the
south terminus of the median strip, 23.40 m (76.8 ft) west of the NW corner of
the Vessel Traffic Center Building, 6.40 m (21.0 ft) north of the northern-most
of two light standards on the median strip, 0.70 m (2.3 ft) WNW of the east edge
of the median strip, and 0.50 m (1.6 ft) NE of the flagpole.
BENCH MARK STAMPING: 4240 S 1988
DESIGNATION: 945 4240 S
MONUMENTATION: Tidal Station disk VM#: 1283
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 61° 7.5' N ( 61.12528) LONGITUDE: 146° 21.4' W (-146.35678)
The bench mark is set in the south end of a concrete pad at the west end of a
blue machine shop warehouse building near the Aleska PipelineService dock, 12 m
(40 ft) SSE of a metal light post, 9 m (30 ft) NNE of a radio tower, and 3.51 m
(11.5 ft) north of the SW corner of the building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 9454240 PUBLICATION DATE: 09/30/2011
Name: VALDEZ, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16708 Latitude: 61° 7.5' N ( 61.12500)
USGS Quad: VALDEZ A-7 Longitude: 146° 21.7' W (-146.36200)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4240 T 2000
DESIGNATION: 945 4240 T
MONUMENTATION: Tidal Station disk VM#: 16234
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: bedrock bluff OPUS PID#: BBBB44
LATITUDE: 61° 7.6' N ( 61.12717) LONGITUDE: 146° 21.6' W (-146.35956)
The bench mark is a disk set in the top of a bedrock bluff at the SE corner of
intersection of roads to Valdez Covention Center and Hazelet Ave, 25 m (82 ft)
(slope distance) SW of light pole #238, 20.30 m (66.6 ft) (slope distance) SE of
center of a 2 ft diameter manhole cover with STORM cast in it, 17.71 m ( 58.1
ft) SE of light pole #237, and 3.51 m (11.5 ft) south of where exposed bedrock
transitions from steep slope to top of bluff.
BENCH MARK STAMPING: 4240 U 2005
DESIGNATION: 945 4240 U
MONUMENTATION: Tidal Station disk VM#: 17889
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 61° 7.5' N ( 61.12481) LONGITUDE: 146° 21.8' W (-146.36339)
The bench mark is a disk set flush in a bedrock cliff just north of the Valdez
Ferry Terminal, 38.71 m (127.0 ft) WSW of the light pole at the corner of Ferry
Way and the access road to the wooden city dock, 30 m (98 ft) NNW of th Ferry
Terminal entrance, 10.70 m (35.1 ft) north of the light pole just north of the
Valdez Ferry Terminal entrance, 9.51 m (31.2 ft) NW of the centerline of Ferry
Way, and 0.70 m (2.3 ft) above ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 9454240 PUBLICATION DATE: 09/30/2011
Name: VALDEZ, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16708 Latitude: 61° 7.5' N ( 61.12500)
USGS Quad: VALDEZ A-7 Longitude: 146° 21.7' W (-146.36200)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4240 W 2005
DESIGNATION: 945 4240 W
MONUMENTATION: Tidal Station disk VM#: 17890
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footing OPUS PID:
LATITUDE: 61° 7.5' N ( 61.12444) LONGITUDE: 146° 21.8' W (-146.36361)
The bench mark is a disk set flush in the SE corner of the 0.5 m (1.6 ft) X 0.6
m (2 ft) X 0.2 m (0.7 ft) high concrete footing for the SE most roof support
member of the Valdez Ferry Terminal, 15.70 m (51.5 ft) SSW of the light pole
west of the entrance to the wooden city dock, 10.39 m (34.1 ft) SE of the
eastern most edge of the Valdez Ferry Terminal, 6.71 m (22.0 ft) NW of the edge
of the riprap protecting the shoreline, 3.60 m (11.8 ft) south of the edge of
the curb on the east side of the Valdez Ferry Terminal, 2.8 m (9.2 ft) NW of the
1 m (3 ft) high steel handrail, and 0.21 m (0.7 ft) above the concrete walkway.
BENCH MARK STAMPING: 4240 V 2005
DESIGNATION: 945 4240 V
MONUMENTATION: Tidal Station disk VM#: 17891
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 61° 7.5' N ( 61.12456) LONGITUDE: 146° 22.0' W (-146.36656)
The bench mark is a disk set flush in bedrock on a rock ledge, 36.6 m (120 ft)
WSW of bench mark STA 11+54.42, 29 m (95 ft) west of the NW corner of a blue
metal building, 27.5 m (90 ft) WSW of the western most light pole in the ferry
vehicle waiting area, 20.5 m (67 ft) north of the edge of the riprap protecting
the shoreline and 1.1 m (3.6 ft) above grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 9454240 PUBLICATION DATE: 09/30/2011
Name: VALDEZ, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16708 Latitude: 61° 7.5' N ( 61.12500)
USGS Quad: VALDEZ A-7 Longitude: 146° 21.7' W (-146.36200)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: STA 11+54.42
DESIGNATION: STA 11+54.42
MONUMENTATION: Bench Mark disk VM#: 17892
AGENCY: Unknown IDB PID#:
SETTING CLASSIFICATION: Concrete OPUS PID:
LATITUDE: 61° 7.5' N ( 61.12444) LONGITUDE: 146° 22.0' W (-146.36586)
The bench mark is a disk set in a 0.2 m (0.6 ft) diameter monument casing
stamped "MON", 37 m (120 ft) ESE of bench mark 4240 V 2005, 28 m (91 ft) NW of
access ramp to ferry, 17.50 m (57.4 ft) NNW of the yellow fire hydrant at the NE
corner of a blue metal building, 14 m (46 ft) south of the rock cliff face on
the eastern side of the ferry vehicle waiting area, 12.31 m (40.4 ft) SSW of the
western most light pole in the ferry vehicle waiting area, and 0.14 m (0.5 ft)
below the surface of the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 9454240 PUBLICATION DATE: 09/30/2011
Name: VALDEZ, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16708 Latitude: 61° 7.5' N ( 61.12500)
USGS Quad: VALDEZ A-7 Longitude: 146° 21.7' W (-146.36200)
T I D A L D A T U M S
Tidal datums at VALDEZ, PRINCE WILLIAM SOUND based on:
LENGTH OF SERIES: 19 YEARS
TIME PERIOD: January 1983 - December 2001
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION:
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (11/11/1981) = 5.198
MEAN HIGHER HIGH WATER MHHW = 3.702
MEAN HIGH WATER MHW = 3.416
MEAN SEA LEVEL MSL = 1.979
MEAN TIDE LEVEL MTL = 1.938
MEAN LOW WATER MLW = 0.460
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (12/14/2008) = -1.660
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 21 1966 6.271 2.854
WAREHOUSE 1966 7.783 4.366
4240 K 1977 7.916 4.500
4240 L 1978 10.455 7.038
4240 S 1988 7.266 3.849
4240 T 2000 15.589 12.173
4240 U 2005 6.524 3.108
4240 W 2005 6.621 3.205
4240 V 2005 8.063 4.647
STA 11+54.42 6.925 3.509
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 9454240 PUBLICATION DATE: 09/30/2011
Name: VALDEZ, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16708 Latitude: 61° 7.5' N ( 61.12500)
USGS Quad: VALDEZ A-7 Longitude: 146° 21.7' W (-146.36200)
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.