U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
Station ID: 8638495 PUBLICATION DATE: 01/14/2011
Name: RICHMOND RIVER LOCKS, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 31.5' N ( 37.52500)
USGS Quad: RICHMOND Longitude: 77° 25.2' W ( -77.42000)
To reach the bench marks from the intersection of Main Street and North 14th
Street in downtown Richmond, Virginia, go SE 1.48 km (0.9 mi) on East Main
Street to the side road on the right, turn right on Pear Street and go SW
downhill for 0.16 km (0.1 mi) to a stop sign at Dock Street and the elevated CSX
rail line, continue southerly about 0.2 km (0.1 mi) under the rail lines into
the parking lot of Great Ship Lock Park. Park in the parking lot and the
elevated USGS tide house is about 60 m (196 ft) SE of the SE part of the parking
lot at the SE downstream wing wall of the Kanawha Canal lock built in 1854.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 8 1941
DESIGNATION: 863 8495 TIDAL 8
MONUMENTATION: Bench Mark disk VM#: 18546
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: GV1234
SETTING CLASSIFICATION: Granite block OPUS PID#: GV1234
LATITUDE: 37° 31.5' N ( 37.52539) LONGITUDE: 77° 25.2' W ( -77.42079)
The primary bench mark is a disk set flush in the top of a 1.96 m x 1.10 m x
0.40 m (6.4 ft x 3.6 ft x 1.3 ft) thick granite block on the north side of the
lock toward the downstream end of the lock, 51.65 m (169.5 ft) SE of the center
of the upstream lock door, 55.01 m (180.5 ft) SE of the flagpole, 23 m (76 ft)
north of bench mark 863 8495 TIDAL 9, 16.73 m (54.9 ft) NW of bench mark 863
8495 City of Richmond, 14.90 m (48.9 ft) NE of westerly most steel leg of the
elevated USGS tide house at the downstream wing wall of the lock, 7.75 m (24.4
ft) north of the center of the downstream lock door, and 0.98 m (3.2 ft) ENE of
the edge of the granite block containing the disk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 8638495 PUBLICATION DATE: 01/14/2011
Name: RICHMOND RIVER LOCKS, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 31.5' N ( 37.52500)
USGS Quad: RICHMOND Longitude: 77° 25.2' W ( -77.42000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 863 8495 TIDAL 9
ALIAS: NO STAMPING 1
MONUMENTATION: Bolt VM#: 18547
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: GV1232
SETTING CLASSIFICATION: Granite block OPUS PID:
LATITUDE: 37° 31.5' N ( 37.52525) LONGITUDE: 77° 25.3' W ( -77.42089)
The bench mark is the top of a 0.10 m (0.3 ft) outside diameter iron eye bolt
with a 0.185 m (0.61 ft) outer diameter captured ring set in the top of a
granite block beneath heavy foliage on the James River side on the downstream
end of the locks, 28.69 m (94.1 ft) SW of bench mark 863 8495 City of Richmond,
15.50 m (50.8 ft) SSW of the center of the downstream lock doors, 7.55 m (24.8
ft) SW of the edge of the lock wall adjacent to a fixed staff, 2.92 m (9.6 ft)
NE of the corner of the abutment, 0.68 m (2.2 ft) NNW of the south edge of the
abutment, and 0.11 m (0.4 ft) above the top of the granite block.
BENCH MARK STAMPING: NO 10 1949
DESIGNATION: 863 8495 TIDAL 10
MONUMENTATION: Bench Mark disk VM#: 18548
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: GV3388
SETTING CLASSIFICATION: Granite curb OPUS PID:
LATITUDE: 37° 31.4' N ( 37.52408) LONGITUDE: 77° 25.1' W ( -77.41858)
The bench mark is a disk set flush in a snub-nose shaped rounded point in the
granite curb at the "Y" intersection of Ash Street and Dock Street, 7.03 m (23.1
ft) ENE of the centerline of Dock Street, 6.75 m (22.1 ft) SSE of wooden power
pole number 535F10, 3.10 m (1.9 ft) WNW of the centerline of Ash Street, 1.70 m
(5.6 ft) SSE of a stop sign and street sign post, and 0.18 m (0.6 ft) above the
pavement immediately to the south.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 8638495 PUBLICATION DATE: 01/14/2011
Name: RICHMOND RIVER LOCKS, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 31.5' N ( 37.52500)
USGS Quad: RICHMOND Longitude: 77° 25.2' W ( -77.42000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 11 1949
DESIGNATION: 863 8495 TIDAL 11
MONUMENTATION: Bench Mark disk VM#: 18549
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Granite curb OPUS PID:
LATITUDE: 37° 31.8' N ( 37.52939) LONGITUDE: 77° 25.5' W ( -77.42531)
The bench mark is a disk set flush in the SE corner of a 1.22 m x 1.22 m (4.0 ft
x 4.0 ft) concrete pier support for the elevated CSX railroad tracks at the
intersection of Dock Street and 22nd Street the closest to the Kanawha canal,
13.30 m (43.6 ft) SW of the centerline of Dock Street, 4.85 m (15.9 ft) NW of
the extended centerline of 22nd Street, 3.45 m (11.3 ft) NE of the edge of water
in the canal, and 0.21 m (0.7 ft) above grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 8638495 PUBLICATION DATE: 01/14/2011
Name: RICHMOND RIVER LOCKS, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 31.5' N ( 37.52500)
USGS Quad: RICHMOND Longitude: 77° 25.2' W ( -77.42000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 863 8495 20 C of R
ALIAS: NO STAMPING 2
MONUMENTATION: See descriptive text VM#: 18550
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: GV1233
SETTING CLASSIFICATION: Granite block OPUS PID:
LATITUDE: 37° 31.5' N ( 37.52531) LONGITUDE: 77° 25.2' W ( -77.42078)
The bench mark is a chiseled 5.5 cm x 4.5 cm x 0.3 cm (2.2 in x 1.8 in x 1/8 in)
deep "U" shape on the outboard edge of the first curved granite block at the SE
end of the locks near the USGS tide house, 18.20 m (59.7 ft) ENE of bench mark
863 8495 TIDAL 9, 11.60 m (38.1 ft) SSE of bench mark 863 8495 TIDAL 8, 10.57 m
(34.7 ft) WSW of bench mark 863 8495 City of Richmond, 9.40 m (30.8 ft) SE of
the center of the downstream lock door, 5.80 m (19.0 ft) NW of the SE corner of
the steel leg on the SE corner of USGS tide house, and 0.57 m (1.9 ft) south of
the measure down point on the top of the fixed staff which is indented in the
granite lock wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 8638495 PUBLICATION DATE: 01/14/2011
Name: RICHMOND RIVER LOCKS, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 31.5' N ( 37.52500)
USGS Quad: RICHMOND Longitude: 77° 25.2' W ( -77.42000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 863 8495 CITY OF RICHMOND
ALIAS: NO STAMPING 3
MONUMENTATION: Chiseled Square VM#: 18551
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Granite block OPUS PID:
LATITUDE: 37° 31.5' N ( 37.52517) LONGITUDE: 77° 25.2' W ( -77.42036)
The bench mark is a faint chiseled square approximately 4mm (0.16 in) deep and
0.04 m (0.1 ft) long on the top and outward tip of a 1.70 m x 0.96 m x 0.40 m
(5.6 ft x 3.1 ft x 1.3 ft) thick flat granite abutment block at the SE corner of
the downstream side of the lock, 28.69 m (94.1 ft) NE of bench mark 863 8495
TIDAL 9, 18.42 m (60.4 ft) ESE of center of the downstream lock door, 16.73 m
(54.9 ft) SE of bench mark 863 8495 TIDAL 8, and 5.44 m (17.8 ft) east of the NE
steel leg supporting the elevated USGS tide house.
BENCH MARK STAMPING: 8495 A 2007
DESIGNATION: 863 8495 A
MONUMENTATION: Tidal Station disk VM#: 18552
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Granite block OPUS PID:
LATITUDE: 37° 31.5' N ( 37.52581) LONGITUDE: 77° 25.3' W ( -77.42106)
The bench mark is a disk set flush in the center and top of a 1.30 m x 1.80 m
(4.3 ft x 5.9 ft) granite block at the upstream river side of the locks, 28.55 m
(93.7 ft) SE of the southeasterly corner of the concrete retaining wall at the
SE part of the spillway upstream of the upstream lock door, 21.04 m (69.0 ft)
WSW of a metal flagpole, 17.50 m (57.4 ft) ENE of center of a 1.8 m (5.91 ft)
diameter poplar tree, 12.05 m (39.5 ft) NW of center of the upstream lock door,
and 4.22 m (13.8 ft) ESE of the outboard corner of the granite abutment.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 8638495 PUBLICATION DATE: 01/14/2011
Name: RICHMOND RIVER LOCKS, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 31.5' N ( 37.52500)
USGS Quad: RICHMOND Longitude: 77° 25.2' W ( -77.42000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8495 B 2007
DESIGNATION: 863 8495 B
MONUMENTATION: Tidal Station disk VM#: 18553
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 37° 31.6' N ( 37.52647) LONGITUDE: 77° 25.3' W ( -77.42097)
The bench mark is a disk set flush in the NW corner of the westerly most of two
trapezoid shaped 2.44 m x 2.12 m (8.0 ft x 7.0 ft) concrete foundations
supporting the elevated CSX dual railroad tracks, 290 m (950 ft) ESE of bench
mark 863 8495 C, 33.05 m (108.4 ft) NW of center of the intersection of Dock and
Pear Streets, 14.55 m (47.7 ft) WNW of center of Dock Street, 13.72 m (45.0 ft)
east of the fence around the Great Ship Lock Park, 0.34 m (1.1 ft) NE of the SE
edge of the concrete foundation, 0.34 m (1.1 ft) SE of the NW edge of concrete
foundation, and 0.30 m (1.0 ft) above the grass.
BENCH MARK STAMPING: 8495 C 2007
DESIGNATION: 863 8495 C
MONUMENTATION: Tidal Station disk VM#: 18554
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 37° 31.7' N ( 37.52833) LONGITUDE: 77° 25.4' W ( -77.42325)
The bench mark is a disk set flush in the north corner of a 1.52 m x 1.52 m x
0.05 m (5.0 ft x 5.0 ft x 0.2 ft) high concrete foundation supporting the
elevated CSX dual railroad tracks, 290 m (950 ft) WNW of bench mark 863 8495 B,
26.10 m (85.6 ft) south of wooden light pole #10868, 22.47 m (73.7 ft) NW of
wooden light pole #10867, 20.42 m (67.0 ft) WSW of the centerline of Dock
Street, and 8.10 m (26.6 ft) ENE of the north edge of the Kanawha canal.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 8638495 PUBLICATION DATE: 01/14/2011
Name: RICHMOND RIVER LOCKS, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 31.5' N ( 37.52500)
USGS Quad: RICHMOND Longitude: 77° 25.2' W ( -77.42000)
T I D A L D A T U M S
Tidal datums at RICHMOND RIVER LOCKS, JAMES RIVER based on:
LENGTH OF SERIES: 2 YEARS
TIME PERIOD: December 2007 - November 2009
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:
HIGHEST OBSERVED WATER LEVEL (01/27/2010) = 5.408
MEAN HIGHER HIGH WATER MHHW = 1.122
MEAN HIGH WATER MHW = 1.055
MEAN SEA LEVEL MSL = 0.587
MEAN TIDE LEVEL MTL = 0.550
MEAN LOW WATER MLW = 0.046
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (12/05/2007) = -0.563
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 8 1941 6.256 5.201
863 8495 TIDAL 9 6.391 5.336
NO 10 1949 4.716 3.661
NO 11 1949 6.559 5.504
863 8495 20 C of R 6.229 5.174
863 8495 CITY OF RICHMOND 6.228 5.173
8495 A 2007 6.244 5.189
8495 B 2007 6.812 5.757
8495 C 2007 6.002 4.947
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 8638495 PUBLICATION DATE: 01/14/2011
Name: RICHMOND RIVER LOCKS, JAMES RIVER
VA
NOAA Chart: 12251 Latitude: 37° 31.5' N ( 37.52500)
USGS Quad: RICHMOND Longitude: 77° 25.2' W ( -77.42000)
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.