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Datums Page Page 1 of 9
Station ID: 8518490 PUBLICATION DATE: 05/16/2011
Name: NEW ROCHELLE
NY
NOAA Chart: 12367 Latitude: 40° 53.6' N ( 40.89330)
USGS Quad: MOUNT VERNON Longitude: 73° 46.9' W ( -73.78170)
To reach the tidal bench marks from Exit 15 of Interstate 95 heading north,
proceed north on U.S. Highway 1 for 0.2 km (0.1 mi) to Weyman Avenue, turn right
onto Weyman Avenue and go 1.3 km (0.8 mi) to Pelham Road, turn left onto Pelham
Road and go to Fort Slocum Road, turn right and follow Fort Slocum Road for 0.5
km (0.3 mi) to Fort Slocum Pier (former ferry terminal). The bench marks are
along Fort Slocum Road, along Harbor Lane, and on the Glen Island Approach
bridge. The tide gage and staff were located on Fort Slocum 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 9
Station ID: 8518490 PUBLICATION DATE: 05/16/2011
Name: NEW ROCHELLE
NY
NOAA Chart: 12367 Latitude: 40° 53.6' N ( 40.89330)
USGS Quad: MOUNT VERNON Longitude: 73° 46.9' W ( -73.78170)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1957
DESIGNATION: TIDAL 1 STA I 45
MONUMENTATION: Tidal Station disk VM#: 2349
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: KU1726
SETTING CLASSIFICATION: Concrete step OPUS PID:
LATITUDE: 40° 53.4' N ( 40.89000) LONGITUDE: 73° 46.9' W ( -73.78170)
The primary bench mark is a disk set in the top of a concrete step on the NE
side and at the east corner of the guard house at Fort Slocum Pier, 0.46 m (1.5
ft) north of the building, 0.30 m (1.0 ft) south of the north edge of the step,
and 0.21 m (0.7 ft) west of the east edge of the step.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 9
Station ID: 8518490 PUBLICATION DATE: 05/16/2011
Name: NEW ROCHELLE
NY
NOAA Chart: 12367 Latitude: 40° 53.6' N ( 40.89330)
USGS Quad: MOUNT VERNON Longitude: 73° 46.9' W ( -73.78170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 2 1957
DESIGNATION: TIDAL 2 STA I 45
MONUMENTATION: Tidal Station disk VM#: 2350
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: KU1724
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 40° 53.5' N ( 40.89170) LONGITUDE: 73° 46.9' W ( -73.78170)
The bench mark is a disk set in the top of a rock outcrop in Neptune Park at the
intersection of Harbor Lane and Fort Slocum Road, 9.45 m (31.0 ft) west of the
centerline of Fort Slocum Road, 9.11 m (30.0 ft) east of the centerline of a
walk, 6.4 m (21 ft) SW of the centerline of Harbor Lane, 4.27 m (14.0 ft) west
of the west side of the stone retaining wall along Fort Slocum Road, and level
with the ground.
BENCH MARK STAMPING: NO 5 1965
DESIGNATION: 851 8490 TIDAL 5
MONUMENTATION: Tidal Station disk VM#: 2351
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 40° 53.6' N ( 40.89330) LONGITUDE: 73° 46.9' W ( -73.78170)
The bench mark is a disk set in the top of a rock outcrop along Harbor Lane just
west of Neptune Park, 4.36 m (14.3 ft) south of the centerline of Harbor Lane,
2.56 m (8.4 ft) east of a power line pole, and 0.06 m (0.2 ft) above ground
level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 9
Station ID: 8518490 PUBLICATION DATE: 05/16/2011
Name: NEW ROCHELLE
NY
NOAA Chart: 12367 Latitude: 40° 53.6' N ( 40.89330)
USGS Quad: MOUNT VERNON Longitude: 73° 46.9' W ( -73.78170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 6 1965
DESIGNATION: 851 8490 TIDAL 6
MONUMENTATION: Tidal Station disk VM#: 2352
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete catch basin OPUS PID:
LATITUDE: 40° 53.6' N ( 40.89330) LONGITUDE: 73° 46.9' W ( -73.78170)
The bench mark is a disk set in the NW corner of a 3 m x 6 m (10 ft x 20 ft)
concrete catch basin at the intersection of Glen Island Approach and Neptune
Island Road, 30.5 m (100 ft) east of the Huquenot Yacht Club entrance, 5.5 m (18
ft) south of Harbor Lane, and 0.61 m (2.0 ft) NW of a stand pipe projecting 0.21
m (0.7 ft) above the concrete.
BENCH MARK STAMPING: Y 384 1965
DESIGNATION: 851 8490 Y 384
MONUMENTATION: Tidal Station disk VM#: 2353
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: KU1721
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 40° 53.6' N ( 40.89330) LONGITUDE: 73° 46.9' W ( -73.78170)
The bench mark is a disk set on the top and near the NE end of a large exposed
bedrock near the east corner of Hudson Park, 55 m (181 ft) SW of the NE side of
a dock, 50.75 m (166.5 ft) NW of the SE end of a dock 68.6 m (20.91 m) west of
the west corner of the Rowing Club Building, 14.33 m (47.0 ft) north of a power
line pole, 0.49 m (1.6 ft) south of the SW end of a rock masonry wall, and 0.76
m (2.5 ft) above the level of the parking area.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 9
Station ID: 8518490 PUBLICATION DATE: 05/16/2011
Name: NEW ROCHELLE
NY
NOAA Chart: 12367 Latitude: 40° 53.6' N ( 40.89330)
USGS Quad: MOUNT VERNON Longitude: 73° 46.9' W ( -73.78170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8490 H 1977
DESIGNATION: 851 8490 H
MONUMENTATION: Tidal Station disk VM#: 2354
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Doorstep OPUS PID:
LATITUDE: 40° 53.6' N ( 40.89330) LONGITUDE: 73° 46.9' W ( -73.78170)
The bench mark is a disk set in the doorstep leading to the mens toilet room at
Neptune Park, 0.15 m (0.5 ft) from the left sidewalk on the north side of the
building.
BENCH MARK STAMPING: 8490 J 1977
DESIGNATION: 851 8490 J
MONUMENTATION: Tidal Station disk VM#: 2355
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete embankment wall OPUS PID:
LATITUDE: 40° 53.6' N ( 40.89330) LONGITUDE: 73° 46.9' W ( -73.78170)
The bench mark is a disk set in the concrete embankment wall at the east end of
Neptune Park, 9.75 m (32.0 ft) north of the south end of the wall, and 4.57 m
(15.0 ft) west of the centerline of Fort Slocum Road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 9
Station ID: 8518490 PUBLICATION DATE: 05/16/2011
Name: NEW ROCHELLE
NY
NOAA Chart: 12367 Latitude: 40° 53.6' N ( 40.89330)
USGS Quad: MOUNT VERNON Longitude: 73° 46.9' W ( -73.78170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8490 K 1977
DESIGNATION: 851 8490 K
MONUMENTATION: Tidal Station disk VM#: 2356
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Doorstep OPUS PID:
LATITUDE: 40° 53.6' N ( 40.89330) LONGITUDE: 73° 46.9' W ( -73.78170)
The bench mark is a disk set in the doorstep of the bridge house on the Glen
Island Approach bridge, 6.71 m (22.0 ft) south of the centerline of Glen Island
Approach, and 1.52 m (5.0 ft) east of the NW corner of the building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 9
Station ID: 8518490 PUBLICATION DATE: 05/16/2011
Name: NEW ROCHELLE
NY
NOAA Chart: 12367 Latitude: 40° 53.6' N ( 40.89330)
USGS Quad: MOUNT VERNON Longitude: 73° 46.9' W ( -73.78170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 851 8490 NO 7
ALIAS: NO STAMPING 1
MONUMENTATION: Tidal Station disk VM#: 2357
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete Sidewalk OPUS PID:
LATITUDE: 40° 53.6' N ( 40.89330) LONGITUDE: 73° 46.9' W ( -73.78170)
The bench mark is a disk set in the east concrete sidewalk at the center of the
Glen Island Approach Bridge leading from New Rochelle to Glen Island, about 137
m (450 ft) SE of Bench Mark NO 6 1965.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 9
Station ID: 8518490 PUBLICATION DATE: 05/16/2011
Name: NEW ROCHELLE
NY
NOAA Chart: 12367 Latitude: 40° 53.6' N ( 40.89330)
USGS Quad: MOUNT VERNON Longitude: 73° 46.9' W ( -73.78170)
T I D A L D A T U M S
Tidal datums at NEW ROCHELLE based on:
LENGTH OF SERIES: 2 YEARS
TIME PERIOD: January 1980 - December 1981
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8516990 WILLETS POINT, LITTLE BAY, EAST RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (02/19/1972) = 3.689
MEAN HIGHER HIGH WATER MHHW = 2.410
MEAN HIGH WATER MHW = 2.301
North American Vertical Datum NAVD88 = 1.279
MEAN SEA LEVEL MSL = 1.194
MEAN TIDE LEVEL MTL = 1.190
MEAN LOW WATER MLW = 0.079
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (02/02/1976) = -1.331
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 1 1957 3.537 1.236
NO 2 1957 5.593 3.292
NO 5 1965 4.698 2.397
NO 6 1965 3.806 1.505
Y 384 1965 4.312 2.011
8490 H 1977 3.688 1.387
8490 J 1977 3.949 1.648
8490 K 1977 7.626 5.325
851 8490 NO 7 7.553 5.252
Foot Notes:
Bench mark Y 384 1965 is based on one differential leveling connection and does
not meet the quality control standards of the NOS. Therefore, caution should be
used when deriving elevations for this mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 9
Station ID: 8518490 PUBLICATION DATE: 05/16/2011
Name: NEW ROCHELLE
NY
NOAA Chart: 12367 Latitude: 40° 53.6' N ( 40.89330)
USGS Quad: MOUNT VERNON Longitude: 73° 46.9' W ( -73.78170)
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.