U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8638476 PUBLICATION DATE: 01/15/2013
Name: JORDAN POINT, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 18.8' N ( 37.31330)
USGS Quad: WESTOVER Longitude: 77° 13.4' W ( -77.22330)
To reach from the intersection of Virginia routes 10 and 36 in Hopewell, drive
SE on route 10 for 5.1 km (3.2 mi) then turn left onto route 106, go north on
route 106 for 2.6 km (1.6 mi) then turn right onto the service road for Jordan
Point Marina, continue north on the service road for 0.11 km (0.1 mi) then turn
right onto the gravel, continue east for 75.0 m (246 ft) and then turn right
into the gate of the boat yard. The tide station is at the northern end of the
T-shaped pier.
T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8638476 PUBLICATION DATE: 01/15/2013
Name: JORDAN POINT, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 18.8' N ( 37.31330)
USGS Quad: WESTOVER Longitude: 77° 13.4' W ( -77.22330)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: JORDAN NO 5 1910 1942
DESIGNATION: JORDAN RM 5
MONUMENTATION: Reference Mark disk VM#: 20497
AGENCY: US Coast and Geodectic Survery
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: In a boulder OPUS PID:
LATITUDE: 37° 18.8' N ( 37.31317) LONGITUDE: 77° 13.4' W ( -77.22344)
The primary bench mark is set in the top of a granite boulder located 55.10 m
(180.8 ft) SW of the west end of the sixth bench Benjamin Harrison bridge as
counted from south to north, 26.80 m (87.9 ft) NW of the NE corner of the
enclosed porch of a residence, 21.50 m (70.5 ft) NW of an electric service pole,
11.74 m (38.5 ft) north of the NE leg of Jordan Point rear range light, 8.99 m
(29.5 ft) north of the NE corner of a fence enclosing Jordan Point rear range
light and 0.30 m (1.0 ft) above the ground.
BENCH MARK STAMPING: 863 8476 A 2011
DESIGNATION: 863 8476 A
MONUMENTATION: Flange-encased Rod VM#: 20496
AGENCY: US Army Corp of Engineers (USACE) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBCQ83
LATITUDE: 37° 18.7' N ( 37.31219) LONGITUDE: 77° 13.3' W ( -77.22225)
The bench mark is located 108.60 m (356.3 ft) ESE of the power pole with a
transformer on the east side of the paved access road south of the first gravel
entrance, 48.80 m (160.1 ft) south of a wooden pile at the SE corner of the boat
lift ways, 46.80 m (153.3 ft) SSE of the NW corner of the west end of the most
northerly steel boat lift way, 32.50 m (106.6 ft) SW of a wooden pile mooring
dolphin, and 30.40 m (99.7 ft) north of the NE corner of a wood and metal fence.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8638476 PUBLICATION DATE: 01/15/2013
Name: JORDAN POINT, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 18.8' N ( 37.31330)
USGS Quad: WESTOVER Longitude: 77° 13.4' W ( -77.22330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: JORDAN No 6 1910 1942
DESIGNATION: JORDAN RM 6
MONUMENTATION: Reference Mark disk VM#: 20498
AGENCY: US Coast and Geodectic Survery
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Sidewalk OPUS PID:
LATITUDE: 37° 18.8' N ( 37.31308) LONGITUDE: 77° 13.4' W ( -77.22339)
The bench mark is a disk set in the concrete sidewalk on the outside of the wire
fence on the east side of the Jordan Point rear range beacon, 17.00 m (55.8 ft)
west of an electric service pole, 10.36 m (34.0 ft) SSE of bench mark Jordan RM
5, 3.87 m (12.7 ft) NNW of the SE corner of a fence enclosing Jordan Point rear
range light, 3.08 m (10.1 ft) ENE of the NE leg of Jordan Point rear range
light, and 2.59 m (8.5 ft) SE of the NE corner of a fence enclosing Jordan Point
rear range light.
BENCH MARK STAMPING: JP-1 2010
DESIGNATION: 863 8476 JP 1
MONUMENTATION: Survey disk VM#: 20499
AGENCY: US Army Corp of Engineers (USACE) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 37° 18.7' N ( 37.31219) LONGITUDE: 77° 13.3' W ( -77.22225)
The bench mark is a disk set in a concrete monument located 20.50 m (67.3 ft)
SSW of the SW corner of a metal building for Jordan Point Marina store, 4.30 m
(14.1 ft) NE of the NE corner of a concrete pad for a fuel tank, 3.80 m (12.5
ft) ENE of the center of a concrete man hole cover, 2.29 m (7.5 ft) SSW of the
north end of a split rail fence, and 1.61 m (5.3 ft) WNW of the SE corner of a
split rail fence.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8638476 PUBLICATION DATE: 01/15/2013
Name: JORDAN POINT, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 18.8' N ( 37.31330)
USGS Quad: WESTOVER Longitude: 77° 13.4' W ( -77.22330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: JP-2 2010
DESIGNATION: 863 8476 JP 2
MONUMENTATION: Survey disk VM#: 20500
AGENCY: US Army Corp of Engineers (USACE) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 37° 18.7' N ( 37.31139) LONGITUDE: 77° 13.3' W ( -77.22211)
The bench mark is a disk set in a concrete monument located 13.70 m (44.9 ft)
SSE of the south end of a guard rail on east side of the paved access road,
13.40 m (44.0 ft) SE of the SE corner of a chain link fence enclosing a bridge
maintenance storage building, 12.50 m (41.0 ft) east of a 0.6 m (2.0 ft)
diameter tuliptree, 2.65 m (8.7 ft) east of the east edge pavement of the access
road, and 2.20 m (7.2 ft) south of the CATV enclosure for Verizon telcom #13.
BENCH MARK STAMPING: JP-3 2010
DESIGNATION: 863 8476 JP 3
MONUMENTATION: Survey disk VM#: 20501
AGENCY: US Army Corp of Engineers (USACE) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 37° 18.7' N ( 37.31108) LONGITUDE: 77° 13.3' W ( -77.22228)
The bench mark is a disk set in a concrete monument located 38.6 m (126.6 ft)
south of the SE corner of a chain link fence, 28.70 m (94.2 ft) south of a 0.6 m
(2.0 ft) diameter tuliptree, 13.10 m (43.0 ft) WSW of the north end of the guard
rail on the east side of the access road, 6.31 m (20.7 ft) west of the west edge
of the pavement of the access road, and 4.66 m (15.3 ft) ESE of the power pole
#0206/160.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8638476 PUBLICATION DATE: 01/15/2013
Name: JORDAN POINT, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 18.8' N ( 37.31330)
USGS Quad: WESTOVER Longitude: 77° 13.4' W ( -77.22330)
T I D A L D A T U M S
Tidal datums at JORDAN POINT, JAMES RIVER based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: February 2012 - April 2012
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8638610 SEWELLS POINT, HAMPTON ROADS
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.832
MEAN HIGH WATER MHW = 0.755
MEAN SEA LEVEL MSL = 0.416
MEAN TIDE LEVEL MTL = 0.395
MEAN LOW WATER MLW = 0.035
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
JORDAN NO 5 1910 1942 1.116 0.361
863 8476 A 2011 1.365 0.610
JORDAN No 6 1910 1942 1.453 0.698
JP-1 2010 2.365 1.610
JP-2 2010 2.252 1.497
JP-3 2010 1.727 0.972
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8638476 PUBLICATION DATE: 01/15/2013
Name: JORDAN POINT, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 18.8' N ( 37.31330)
USGS Quad: WESTOVER Longitude: 77° 13.4' W ( -77.22330)
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.