U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8468191 PUBLICATION DATE: 06/15/2016
Name: SAUGATUCK, SAUGATUCK RIVER
CT
NOAA Chart: 12364 Latitude: 41° 7.2' N ( 41.12000)
USGS Quad: SHERWOOD POINT Longitude: 73° 22.1' W ( -73.36833)
To reach the station from the US Highway 1 (State Street East) bridge over the
Saugatuck River in Westport, proceed west on US Highway 1 for 0.1 km (0.1 mi) to
State Highway 33 (Riverside Avenue). Turn left and proceed south on Riverside
Avenue for 1.9 km (1.2 mi) to the intersection with Treadwell Avenue, turn left
and continue on Riverside Avenue for 0.5 km (0.3 mi) southeast and then south to
All Seasons Marine Works at 609 Riverside Avenue. The bench marks are located
between the State Highway 136 bridge over the Saugatuck River and Metro North
railway bridge over the Saugatuck River. The tide gauge is located on the south
pier of the All Seasons Marine Works boat lift dock.
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: 8468191 PUBLICATION DATE: 06/15/2016
Name: SAUGATUCK, SAUGATUCK RIVER
CT
NOAA Chart: 12364 Latitude: 41° 7.2' N ( 41.12000)
USGS Quad: SHERWOOD POINT Longitude: 73° 22.1' W ( -73.36833)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: P 35 1965
DESIGNATION: P 35
MONUMENTATION: Bench Mark disk VM#: 21408
AGENCY: US Coast & Geodetic Survey IDB PID#: LX0804
SETTING CLASSIFICATION: Pier OPUS PID:
LATITUDE: 41° 7.2' N ( 41.11936) LONGITUDE: 73° 22.2' W ( -73.36928)
The primary bench mark is a disk set in a stone block bridge support on the N
side of the steel railroad bridge on the E side of railroad place, 16.75 m (55.0
ft) N of the S side of the stone bridge footing, 15.59 m (51.1 ft) SSE of a
power pole numbered 25659-23k16, 6.21 m (20.4 ft) E of the centerline of
railroad place, 1.92 m (6.3 ft) SE of the end post of a steel guardrail, 1.15 m
(3.8 ft) N of the N side of the steel bridge girder and about 1.60 m (5.2 ft)
higher than the ground.
BENCH MARK STAMPING: 8191 A 2015
DESIGNATION: 846 8191 A
MONUMENTATION: Bench Mark disk VM#: 21409
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Bridge abutment OPUS PID#: BBDV08
LATITUDE: 41° 7.4' N ( 41.12286) LONGITUDE: 73° 22.1' W ( -73.36878)
The bench mark is a disk set in the NE concrete bridge abutment of the state
highway 136 bridge over the Saugatuck River, 16.50 m (54.1 ft) W of the S
drawbridge closure gate, 14.99 m (49.2 ft) WSW of the N drawbridge closure gate,
5.38 m (17.7 ft) E of the second guard rail post W of the NE bridge abutment,
3.53 m (11.6 ft) NNW of the intersection of the centerline of state highway 136
and the bridge abutment and 1.30 m (4.3 ft) S of a fence corner on the NW side
of the bridge.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8468191 PUBLICATION DATE: 06/15/2016
Name: SAUGATUCK, SAUGATUCK RIVER
CT
NOAA Chart: 12364 Latitude: 41° 7.2' N ( 41.12000)
USGS Quad: SHERWOOD POINT Longitude: 73° 22.1' W ( -73.36833)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8191 B 2015
DESIGNATION: 846 8191 B
MONUMENTATION: Bench Mark disk VM#: 21410
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Flag pole base OPUS PID:
LATITUDE: 41° 7.3' N ( 41.12197) LONGITUDE: 73° 22.2' W ( -73.37017)
The bench mark is a disk set in a concrete foundation for a flagpole in front of
a fire station, 16.74 m (54.9 ft) SSE of a utility pole numbered 26279, 13.19 m
(43.3 ft) E of the centerline of Riverside Avenue, 10.63 m (34.9 ft) NNW of the
SW most corner of the fire station building, 9.89 m (32.4 ft) NNE of a utility
pole numbered 26278 at the SW corner of the fire station and 7.24 m (23.8 ft) S
of the NW most corner of the fire station building.
BENCH MARK STAMPING: 8191 C 2015
DESIGNATION: 846 8191 C
MONUMENTATION: Bench Mark disk VM#: 21411
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Sill of garage door OPUS PID:
LATITUDE: 41° 7.2' N ( 41.11994) LONGITUDE: 73° 22.2' W ( -73.36964)
The bench mark is a disk set in concrete in the garage door opening on the E
side of the building, 14.25 m (46.8 ft) NNW of the SW corner of a concrete pad
leading to the boat lift pier, 9.00 m (29.5 ft) N of the SE most outside corner
of the garage building, 7.54 m (24.7 ft) SSW of the SE corner of the building
just E of the man door, 6.15 m (20.2 ft) S of the inside corner on the E side of
the building and 4.84 m (15.9 ft) WNW of the NW corner of a concrete pad leading
to the boat lift pier.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8468191 PUBLICATION DATE: 06/15/2016
Name: SAUGATUCK, SAUGATUCK RIVER
CT
NOAA Chart: 12364 Latitude: 41° 7.2' N ( 41.12000)
USGS Quad: SHERWOOD POINT Longitude: 73° 22.1' W ( -73.36833)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: A 33 1965
DESIGNATION: A 33
MONUMENTATION: Bench Mark disk VM#: 21412
AGENCY: US Coast & Geodetic Survey IDB PID#: LX0805
SETTING CLASSIFICATION: Pier OPUS PID:
LATITUDE: 41° 7.2' N ( 41.12058) LONGITUDE: 73° 22.2' W ( -73.37053)
The bench mark is a disk set vertically in a concrete column on the W side of
Riverside Avenue supporting the I-95 elevated highway, 29.55 m (96.9 ft) N of a
traffic signal light post at the NW corner of Riverside Avenue and Charles
street, 29.53 m (96.9 ft) S of a light pole on the W side of Riverside Avenue
under I-95 overpass, 8.91 m (29.2 ft) N of a no parking anytime sign, 6.10 m
(20.0 ft) W of the curb face of Riverside Avenue and set vertically in the face
of the concrete column about 0.34 m (1.1 ft) higher than the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8468191 PUBLICATION DATE: 06/15/2016
Name: SAUGATUCK, SAUGATUCK RIVER
CT
NOAA Chart: 12364 Latitude: 41° 7.2' N ( 41.12000)
USGS Quad: SHERWOOD POINT Longitude: 73° 22.1' W ( -73.36833)
T I D A L D A T U M S
Tidal datums at SAUGATUCK, SAUGATUCK RIVER based on:
LENGTH OF SERIES: 5 MONTHS
TIME PERIOD: April 2015 - August 2015
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8467150 BRIDGEPORT, BRIDGEPORT HARBOR
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 2.309
MEAN HIGH WATER MHW = 2.205
North American Vertical Datum NAVD88 = 1.191
MEAN SEA LEVEL MSL = 1.145
MEAN TIDE LEVEL MTL = 1.140
MEAN LOW WATER MLW = 0.074
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
P 35 1965 5.138 2.933
8191 A 2015 4.737 2.532
8191 B 2015 5.672 3.467
8191 C 2015 3.462 1.257
A 33 1965 6.465 4.260
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8468191 PUBLICATION DATE: 06/15/2016
Name: SAUGATUCK, SAUGATUCK RIVER
CT
NOAA Chart: 12364 Latitude: 41° 7.2' N ( 41.12000)
USGS Quad: SHERWOOD POINT Longitude: 73° 22.1' W ( -73.36833)
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.