U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 8 Station ID: 8443970 PUBLICATION DATE: 12/12/2018 Name: BOSTON, BOSTON HARBOR MA NOAA Chart: 13272 Latitude: 42° 21.2' N ( 42.35392) USGS Quad: BOSTON SOUTH Longitude: 71° 3.0' W ( -71.05033) To reach the water level station from either direction of U.S. Interstate 93, take exit 23 and follow the signs to the Financial District. Proceed south on Surface Road until it becomes Purchase Road at the intersection with High Street. Continue south on Purchase Road for about three blocks. At the intersection with Congress Street, turn SSE (left) and then NE (left) onto Atlantic Avenue. Proceed on Atlantic Avenue for one block to the intersection with Seaport Blvd, proceed straight and after the James Hook & Company building turn SE (right) to Northern Avenue and the U.S. Coast Guard Building. The water level station is SE of the U.S. Coast Guard Building at the NW end of the Northern Avenue bridge. The bench marks are in the vicinity of the U.S. Coast Guard Building, Marriott's Custom House, and the U.S. Post Office. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 3970 C 1991 DESIGNATION: 844 3970 C MONUMENTATION: Tidal Station disk VM#: 13804 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Granite bridge abutment OPUS PID: LATITUDE: 42° 21.3' N ( 42.35481) LONGITUDE: 71° 3.0' W ( -71.05047) The primary bench mark is a disc set in the top of the granite bulkhead cap adjacent to the SW corner of the Northern Avenue Bridge at its NW end and the burnt remains of the James Hook and Company Building. The bench mark is located 12.89 m (42.29 ft) south of the northernmost bollard on the seawall, and 0.42 m (1.38 ft) west of the west edge of the cap.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 8 Station ID: 8443970 PUBLICATION DATE: 12/12/2018 Name: BOSTON, BOSTON HARBOR MA NOAA Chart: 13272 Latitude: 42° 21.2' N ( 42.35392) USGS Quad: BOSTON SOUTH Longitude: 71° 3.0' W ( -71.05033) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 15 1950 DESIGNATION: 844 3970 TIDAL 15 MONUMENTATION: Tidal Station disk VM#: 186 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: MY0556 SETTING CLASSIFICATION: Granite foundation OPUS PID: LATITUDE: 42° 21.5' N ( 42.35886) LONGITUDE: 71° 3.2' W ( -71.05342) The bench mark is a disk set in the top of the granite ledge around the base of the U.S. Custom House at the intersection of India and Central Streets, 6.40 m (21.0 ft) east of the center of the entrance to the building, 5.03 m (16.5 ft) west of the SE corner of the building, 0.3 m (1 ft) south of the south face of the building, and 0.3 m (1 ft) above the sidewalk. BENCH MARK STAMPING: FED 2 ELEV 20.186 DESIGNATION: 844 3970 TIDAL 1 MONUMENTATION: Tidal Station disk VM#: 190 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: MY0557 SETTING CLASSIFICATION: Stone step OPUS PID: LATITUDE: 42° 21.4' N ( 42.35711) LONGITUDE: 71° 3.4' W ( -71.05722) The bench mark is a disk set in the south end of the bottom step of the Devonshire Street entrance of the U.S. Post Office which is in the business district bounded by Devonshire, Water, Congress and Milk Streets, 7.62 m (25.0 ft) east of the centerline of Devonshire Street, and 2.19 m (7.2 ft) south of the centerline of the steps leading to the post office.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 8 Station ID: 8443970 PUBLICATION DATE: 12/12/2018 Name: BOSTON, BOSTON HARBOR MA NOAA Chart: 13272 Latitude: 42° 21.2' N ( 42.35392) USGS Quad: BOSTON SOUTH Longitude: 71° 3.0' W ( -71.05033) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 3970 D 2000 DESIGNATION: 844 3970 D MONUMENTATION: Tidal Station disk VM#: 16235 AGENCY: National Geodetic Survey (NGS) IDB PID#: AJ4030 SETTING CLASSIFICATION: Granite sea wall cap OPUS PID#: AJ4030 LATITUDE: 42° 21.7' N ( 42.36122) LONGITUDE: 71° 2.0' W ( -71.03414) The bench mark is a disk set in the granite bulkhead cap between two metal bollards of the seawall at the Christopher Columbus Park located at the intersection of Atlantic Avenue and Richmond Streets, 31.28 m (102.6 ft) ENE of the east face of the Christopher Columbus Statue, and 7.50 m (24.6 ft) ENE of the granite foundation of the third lamp post north of the south end of the granite steps at the park entrance.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 8 Station ID: 8443970 PUBLICATION DATE: 12/12/2018 Name: BOSTON, BOSTON HARBOR MA NOAA Chart: 13272 Latitude: 42° 21.2' N ( 42.35392) USGS Quad: BOSTON SOUTH Longitude: 71° 3.0' W ( -71.05033) T I D A L B E N C H M A R K S BENCH MARK STAMPING: E 44 1978 DESIGNATION: E 44 MONUMENTATION: Bench Mark disk VM#: 18189 AGENCY: National Geodetic Survey IDB PID#: MY2079 SETTING CLASSIFICATION: Door Sill OPUS PID: LATITUDE: 42° 21.5' N ( 42.35872) LONGITUDE: 71° 3.5' W ( -71.05908) The bench mark is a disk set in a 0.46 m (1.5 ft) wide door sill at a fire exit door located in the west face of the school committee building at 26 Court Street, 32.00 m (105.0 ft) south of the south curb return of Court Street, 22.86 m (75.0 ft) north of the south curb return of Court Street, 22.89 m (75.1 ft) south of the extension of the north face of the building, 9.45 m (31.0 ft) north of the center of the main west side entrance to the building, and 2.44 m (8.0 ft) east of the east curb return of Court Square.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 8 Station ID: 8443970 PUBLICATION DATE: 12/12/2018 Name: BOSTON, BOSTON HARBOR MA NOAA Chart: 13272 Latitude: 42° 21.2' N ( 42.35392) USGS Quad: BOSTON SOUTH Longitude: 71° 3.0' W ( -71.05033) T I D A L B E N C H M A R K S BENCH MARK STAMPING: H 44 1978 DESIGNATION: H 44 MONUMENTATION: Bench Mark disk VM#: 18190 AGENCY: National Geodetic Survey IDB PID#: MY2080 SETTING CLASSIFICATION: Window Ledge OPUS PID: LATITUDE: 42° 21.3' N ( 42.35561) LONGITUDE: 71° 3.5' W ( -71.05781) The bench mark is a disk set horizontally in a 0.79 m (2.6 ft) wide ledge for a large window located in the west face of the 100 Franklin Building, 20.8 m (68.2 ft) south of the center of the west entrance of the building, 9.08 m (29.8 ft) north of the SW corner of the building, and 2.47 m (8.1 ft) east of the east curb return of Arch Street.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 8 Station ID: 8443970 PUBLICATION DATE: 12/12/2018 Name: BOSTON, BOSTON HARBOR MA NOAA Chart: 13272 Latitude: 42° 21.2' N ( 42.35392) USGS Quad: BOSTON SOUTH Longitude: 71° 3.0' W ( -71.05033) T I D A L B E N C H M A R K S BENCH MARK STAMPING: J 12 RESET MASS. G.S. 1936 13.321 DESIGNATION: J 12 RESET MONUMENTATION: Bench Mark disk VM#: 20267 AGENCY: USC&GS IDB PID: SETTING CLASSIFICATION: Steps OPUS PID: LATITUDE: 42° 21.2' N ( 42.35361) LONGITUDE: 71° 3.2' W ( -71.05333) The bench mark is a brass disc set flush in the third step at the southernmost set of steps, at the corner entrance to the Atlantic Wharf building located 11.05 m (36.3 ft) from the face of the curb at the center of the crosswalk on the SE side of Atlantic avenue, 8.23 m (27.0 ft) NE of a fire hydrant on the east side of Congress street, and 3.83 m (12.6 ft) SW from the door sill at the center of both doors at the entrance to the Atlantic Wharf building. BENCH MARK STAMPING: L 12 1936 DESIGNATION: 844 3970 L 12 MONUMENTATION: Bench Mark disk VM#: 22878 AGENCY: US Coast and Geodetic Survey IDB PID: SETTING CLASSIFICATION: Granite step OPUS PID: LATITUDE: 42° 21.5' N ( 42.35872) LONGITUDE: 71° 3.4' W ( -71.05694) The bench mark is a disk set atop the bottom step on the east side of the entrance to the old state house located at the corner of Congress Street and State Street, 15.85m (52.0 ft) north of the SE corner of the old state house, 2.74m (9.0 ft) west of the east side of the sidewalk running along the street, and 0.44m (1.4 ft) east of the west side brick wall of the old state house.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 7 of 8 Station ID: 8443970 PUBLICATION DATE: 12/12/2018 Name: BOSTON, BOSTON HARBOR MA NOAA Chart: 13272 Latitude: 42° 21.2' N ( 42.35392) USGS Quad: BOSTON SOUTH Longitude: 71° 3.0' W ( -71.05033) T I D A L D A T U M S Tidal datums at BOSTON, BOSTON HARBOR based on: LENGTH OF SERIES: 19 YEARS TIME PERIOD: January 1983 - December 2001 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (01/04/2018) = 4.622 MEAN HIGHER HIGH WATER MHHW = 3.131 MEAN HIGH WATER MHW = 2.996 North American Vertical Datum NAVD88 = 1.678 MEAN SEA LEVEL MSL = 1.585 MEAN TIDE LEVEL MTL = 1.550 MEAN LOW WATER MLW = 0.103 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (03/24/1940) = -1.135 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 3970 C 1991 6.272 3.275 NO 15 1950 5.072 2.076 FED 2 ELEV 20.186 7.589 4.593 3970 D 2000 4.250 1.254 E 44 1978 12.576 9.579 H 44 1978 8.426 5.430 J 12 RESET MASS. G.S. 1936 13.321 5.471 2.474 L 12 1936 9.462 6.466 Foot Notes: Bench mark L 12 1936 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 8 of 8 Station ID: 8443970 PUBLICATION DATE: 12/12/2018 Name: BOSTON, BOSTON HARBOR MA NOAA Chart: 13272 Latitude: 42° 21.2' N ( 42.35392) USGS Quad: BOSTON SOUTH Longitude: 71° 3.0' W ( -71.05033) 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.