U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8469057 PUBLICATION DATE: 03/15/2016
Name: MIANUS, MIANUS RIVER
CT
NOAA Chart: 12367 Latitude: 41° 2.4' N ( 41.03919)
USGS Quad: STAMFORD Longitude: 73° 35.5' W ( -73.59203)
To reach the station from the intersection of US Highway 1 (East Putnam Avenue)
and Riverside Avenue in Riverside, proceed NW on US Highway 1 for 0.4 km to the
intersection with River Road. turn left and proceed south on River Road for 0.5
km (0.3 mi) to Beacon Point Marine on the left. The tide gauge is located on the
seawall at the northeast corner of the Beacon Point Marine property. The bench
marks are located between the US Highway 1 bridge over the Mianus River and the
Cos Cob public marina.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 9057 A 2015
DESIGNATION: 846 9057 A
MONUMENTATION: Bench Mark disk VM#: 21396
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 41° 2.4' N ( 41.04003) LONGITUDE: 73° 35.5' W ( -73.59200)
The primary bench mark is a disk set in a rock outcrop in the right-of-way of
the residence of 88 river road on the W side of the street, 27.41 m (89.9 ft)
WSW of a fire hydrant, 20.45 m (67.1 ft) NE of the center of a catch basin,
18.74 m (61.5 ft) SW of the center of the catch basin S at the driveway of 88
river road, 11.04 m (36.2 ft) N of a utility pole numbered 69426 and 4.96 m
(16.3 ft) WNW of the centerline of river road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8469057 PUBLICATION DATE: 03/15/2016
Name: MIANUS, MIANUS RIVER
CT
NOAA Chart: 12367 Latitude: 41° 2.4' N ( 41.03919)
USGS Quad: STAMFORD Longitude: 73° 35.5' W ( -73.59203)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9057 B 2015
DESIGNATION: 846 9057 B
MONUMENTATION: Bench Mark disk VM#: 21397
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Concrete retaining wall OPUS PID:
LATITUDE: 41° 2.4' N ( 41.03939) LONGITUDE: 73° 35.5' W ( -73.59244)
The bench mark is a disk set near the NW corner of a concrete retaining wall,
31.23 m (102.5 ft) NW of a jog in the concrete retaining wall along the N side
of the boat storage yard, 11.60 m (38.1 ft) SE of the centerline of river road,
9.35 m (30.7 ft) WSW of the SW corner of a house at 133 river road, 8.89 m (29.2
ft) S of a power pole numbered 69425 that is N of the public access trail and
6.43 m (21.1 ft) E of a 10-inch (25 cm) deciduous tree.
BENCH MARK STAMPING: 9057 C 2015
DESIGNATION: 846 9057 C
MONUMENTATION: Bench Mark disk VM#: 21398
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Bridge abutment OPUS PID:
LATITUDE: 41° 2.1' N ( 41.03442) LONGITUDE: 73° 35.8' W ( -73.59717)
The bench mark is a disk set in the NW concrete bridge abutment just E of the
intersection of river and Strickland roads, 29.64 m (97.2 ft) W of a concrete
column to the I-95 elevated highway, 26.85 m (88.1 ft) NE of a power pole with a
light at the SW corner of the intersection, 17.69 m (58.0 ft) E of the stop sign
at the NE corner of the intersection, 11.04 m (36.2 ft) E of a rock seawall and
8.06 m (26.4 ft) ENE of a sewer man hole that is N of the centerline of river
road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8469057 PUBLICATION DATE: 03/15/2016
Name: MIANUS, MIANUS RIVER
CT
NOAA Chart: 12367 Latitude: 41° 2.4' N ( 41.03919)
USGS Quad: STAMFORD Longitude: 73° 35.5' W ( -73.59203)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9057 D 2015
DESIGNATION: 846 9057 D
MONUMENTATION: Bench Mark disk VM#: 21399
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Concrete abutment to a pier OPUS PID#: BBDV09
LATITUDE: 41° 1.9' N ( 41.03236) LONGITUDE: 73° 35.8' W ( -73.59708)
The bench mark is a disk set in a concrete abutment at the base of the Cos Cob
public pier, 44.84 m (147.1 ft) NE of a utility pole numbered 67129, 40.43 m
(132.6 ft) ESE of a utility pole numbered 67128, 8.09 m (26.5 ft) NNE of the N
end of a guardrail on the E side of the parking lot, 7.96 m (26.1 ft) W of the
center of the wooden door to the pier and 4.43 m (14.5 ft) SSW of a unnumbered
utility pole just north of the abutment.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8469057 PUBLICATION DATE: 03/15/2016
Name: MIANUS, MIANUS RIVER
CT
NOAA Chart: 12367 Latitude: 41° 2.4' N ( 41.03919)
USGS Quad: STAMFORD Longitude: 73° 35.5' W ( -73.59203)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: S 31 1965
DESIGNATION: S 31
MONUMENTATION: Bench Mark disk VM#: 21400
AGENCY: US Coast and Geodetic Survey IDB PID#: LX1163
SETTING CLASSIFICATION: Retaining wall OPUS PID#: LX1163
LATITUDE: 41° 2.5' N ( 41.04239) LONGITUDE: 73° 35.4' W ( -73.58975)
The bench mark is a disk set in a concrete retaining wall N of the W end of the
bridge and S of a spillway, 18.97 m (62.2 ft) S of the N end of the fence on top
of the retaining wall, 10.93 m (6.3 ft) S of a flag pole, 4.60 m (15.1 ft) ESE
of a manhole cover near the SE corner of the parking lot, 4.27 m (14.0 ft) ENE
of an unnumbered power pole, and 3.59 m (11.8 ft) N of the corner where the wall
meets the bridge.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8469057 PUBLICATION DATE: 03/15/2016
Name: MIANUS, MIANUS RIVER
CT
NOAA Chart: 12367 Latitude: 41° 2.4' N ( 41.03919)
USGS Quad: STAMFORD Longitude: 73° 35.5' W ( -73.59203)
T I D A L D A T U M S
Tidal datums at MIANUS, MIANUS RIVER based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: October 2015 - December 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 = 2.376
MEAN HIGH WATER MHW = 2.265
North American Vertical Datum NAVD88 = 1.231
MEAN SEA LEVEL MSL = 1.175
MEAN TIDE LEVEL MTL = 1.169
MEAN LOW WATER MLW = 0.073
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
9057 A 2015 4.930 2.665
9057 B 2015 6.375 4.110
9057 C 2015 3.554 1.289
9057 D 2015 3.754 1.489
S 31 1965 5.506 3.241
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8469057 PUBLICATION DATE: 03/15/2016
Name: MIANUS, MIANUS RIVER
CT
NOAA Chart: 12367 Latitude: 41° 2.4' N ( 41.03919)
USGS Quad: STAMFORD Longitude: 73° 35.5' W ( -73.59203)
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.