B.08.02_Published Bench Mark Sheet for 8638901 CBBT CHESAPEAKE CHANNEL VA.pdf

7/16/2021 Published Bench Mark Sheet for 8638901 CBBT, CHESAPEAKE CHANNEL VA https://tidesandcurrents.noaa.gov/benchmarks/8638901.html 1/7

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5

Station ID: 8638901 PUBLICATION DATE: 10/30/2020 Name: CBBT, CHESAPEAKE CHANNEL

VA

NOAA Chart: 12254 Latitude: 37° 2.0' N ( 37.03290) USGS Quad: CAPE HENRY Longitude: 76° 5.0' W ( -76.08330)

To reach the tidal bench marks from the toll booth on the south end of Chesapeake Bay Bridge Tunnel (CBBT) in Virginia Beach, proceed north on U.S.

Highway 13 for 8 km (4.3 mi) to the south entrance of the Thimble Shoal Tunnel.

The bench marks are located on the south bound road and the third island.

T I D A L B E N C H M A R K S

PRIMARY BENCH MARK STAMPING: 8901 A 2016

DESIGNATION: 863 8901 A

MONUMENTATION: Bench Mark disk VM#: 22482

AGENCY: NOS IDB PID:

SETTING CLASSIFICATION: Building foundation OPUS PID:

LATITUDE: 37° 2.2' N ( 37.03656) LONGITUDE: 76° 4.6' W ( -76.07666)

The primary bench mark is a NOS disk located on the Chesapeake Bay Bridge Tunnel third island, set in the foundation of a vent building on the NW facing wall,

26.5 m (86.9 ft) SW of the corner of the vent building, 24.6 m (80.7 ft) SE of the northwest facing sea wall, and 5.4 m (17.7 ft) NE of the west corner of the vent building.

https://tidesandcurrents.noaa.gov/benchmarks/8638901.html 2/7

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

VA

NOAA Chart: 12254 Latitude: 37° 2.0' N ( 37.03290) USGS Quad: CAPE HENRY Longitude: 76° 5.0' W ( -76.08330)

T I D A L B E N C H M A R K S

BENCH MARK STAMPING: 8901 B 2016

DESIGNATION: 863 8901 B

MONUMENTATION: Bench Mark disk VM#: 22483

AGENCY: NOS IDB PID:

SETTING CLASSIFICATION: Retaining wall OPUS PID:

LATITUDE: 37° 2.2' N ( 37.03603) LONGITUDE: 76° 4.7' W ( -76.07783)

The bench mark is a NOS brass disk located on the Chesapeake Bay Bridge Tunnel on the third island set on the northwest corner of the seawall, 59.2 m (194.2

ft) SW of the light pole closest to the vent building, 43.7 m (143.4 ft) north of the light pole second closest to the vent building, 24.6 m (80.7 ft) NW of the northwest facing tunnel wall, and 0.4 m (1.3 ft) SE of the northwest face of the seawall.

BENCH MARK STAMPING: 8901 C 2016

DESIGNATION: 863 8901 C

MONUMENTATION: Bench Mark disk VM#: 22484

AGENCY: NOS IDB PID:

SETTING CLASSIFICATION: Retaining wall OPUS PID:

LATITUDE: 37° 2.1' N ( 37.03486) LONGITUDE: 76° 4.8' W ( -76.07939)

The bench mark is a NOS brass disk set in the Chesapeake Bay Bridge Tunnel on the third island and is set in the corner of the NW facing massive concrete retaining wall, 74.3 m (243.8 ft) NE of the west corner of the seawall, 25.4 m (83.3 ft) north of the light pole located at tunnel entrance, 12.6 m (41.3 ft) NW of the northeast facing tunnel wall, and 7.2 m (23.6 ft) SE of the northwest https://tidesandcurrents.noaa.gov/benchmarks/8638901.html 3/7 facing sea wall.

https://tidesandcurrents.noaa.gov/benchmarks/8638901.html 4/7

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

VA

NOAA Chart: 12254 Latitude: 37° 2.0' N ( 37.03290) USGS Quad: CAPE HENRY Longitude: 76° 5.0' W ( -76.08330)

T I D A L B E N C H M A R K S

BENCH MARK STAMPING:

DESIGNATION: 99

MONUMENTATION: Bench Mark disk VM#: 22485

AGENCY: IDB PID:

SETTING CLASSIFICATION: Retaining wall OPUS PID:

LATITUDE: 37° 2.2' N ( 37.03639) LONGITUDE: 76° 4.6' W ( -76.07722)

BENCH MARK STAMPING:

DESIGNATION: 78

MONUMENTATION: Bench Mark disk VM#: 22486

AGENCY: IDB PID:

SETTING CLASSIFICATION: Retaining wall OPUS PID:

LATITUDE: 37° 2.2' N ( 37.03672) LONGITUDE: 76° 4.6' W ( -76.07631)

https://tidesandcurrents.noaa.gov/benchmarks/8638901.html 5/7

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

VA

NOAA Chart: 12254 Latitude: 37° 2.0' N ( 37.03290) USGS Quad: CAPE HENRY Longitude: 76° 5.0' W ( -76.08330)

T I D A L D A T U M S

Tidal datums at CBBT, CHESAPEAKE CHANNEL based on:

LENGTH OF SERIES: 2 YEARS

TIME PERIOD: September 2017 - August 2019

TIDAL EPOCH: 1983-2001

CONTROL TIDE STATION: 8632200 KIPTOPEKE, CHESAPEAKE BAY

Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

HIGHEST OBSERVED WATER LEVEL (09/06/2019) = 1.904

MEAN HIGHER HIGH WATER MHHW = 0.919

MEAN HIGH WATER MHW = 0.846

MEAN SEA LEVEL MSL = 0.449

MEAN TIDE LEVEL MTL = 0.441

MEAN LOW WATER MLW = 0.036

MEAN LOWER LOW WATER MLLW = 0.000

LOWEST OBSERVED WATER LEVEL (01/06/2018) = -0.505

Bench Mark Elevation Information In METERS above:

Stamping or Designation MLLW MHW

8901 A 2016 8.645 7.799 8901 B 2016 8.152 7.306 8901 C 2016 8.086 7.240 99 8.135 7.289 78 8.186 7.340 http://tidesandcurrents.noaa.gov/datum_options.html#MHHW http://tidesandcurrents.noaa.gov/datum_options.html#MHW http://tidesandcurrents.noaa.gov/datum_options.html#MSL http://tidesandcurrents.noaa.gov/datum_options.html#MTL http://tidesandcurrents.noaa.gov/datum_options.html#MLW http://tidesandcurrents.noaa.gov/datum_options.html#MLLW https://tidesandcurrents.noaa.gov/benchmarks/8638901.html 6/7

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

VA

NOAA Chart: 12254 Latitude: 37° 2.0' N ( 37.03290) USGS Quad: CAPE HENRY Longitude: 76° 5.0' W ( -76.08330)

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) http://www.ngs.noaa.gov/Tidal_Elevation/diagram.jsp http://www.ngs.noaa.gov/Tidal_Elevation/diagram.jsp https://tidesandcurrents.noaa.gov/benchmarks/8638901.html 7/7 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.