U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 PUBLICATION DATE: 01/29/1988 Station ID: 9446545 SUPERCEDED DATE: 04/21/2003 Name: TACOMA, COMMENCEMENT BAY WASHINGTON NOAA Chart: 18453 Latitude: 47° 15.3' N USGS Quad: TACOMA NORTH Longitude: 122° 25.9' W To reach the tidal bench marks from the intersection of Pacific Avenue and East 11st Street in Tacoma, Washington proceed east along 11th Street for 0.5 miles (0.8 km), cross over the 11th Street Bridge and city waterway to east E Street, turn left (north), then another left (west) immediately onto 11th Street lower level and travel 0.2 miles (0.3 km) to the Tacoma City Fire boat station and slip adjacent to the north side of the 11th Street bridge. The bench marks are located along the Railroad tracks around the station, and the tide gage and staff were located on a piling clump 72 feet (22 m) west of the onshore fire boat station. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: E 406 1965 MONUMENTATION: Survey Disk VM#: 9161 AGENCY: PID#: SY0534 SETTING CLASSIFICATION: Concrete Curb The bench mark is set in the top of the east end of the south concrete curb of the East 11th Street bridge over the city waterway, 6.0 feet (1.8 m) south of the south curb of East 11th Street, 0.5 foot (0.2 m) north of the east end of a guard rail, 0.5 foot (0.2 m) north of the NW corner of the top of five concrete steps, and about the level with the street. BENCH MARK STAMPING: F 11 1920 ELEV. 26.227 FT. MONUMENTATION: Survey Disk VM#: 9158 AGENCY: PID#: SY0541 SETTING CLASSIFICATION: Wall The bench mark is set in the east wall of a heating plant building, at the SE corner of the main building of the Union Station, 4.0 feet (1.2 m) south of the south stairway leading from the station platform to Pacific Avenue, 1.5 feet (0.5 m) from the north wall of the building, and 3.5 feet (1.1 m) above the platform.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 PUBLICATION DATE: 01/29/1988 Station ID: 9446545 SUPERCEDED DATE: 04/21/2003 Name: TACOMA, COMMENCEMENT BAY WASHINGTON NOAA Chart: 18453 Latitude: 47° 15.3' N USGS Quad: TACOMA NORTH Longitude: 122° 25.9' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: G 11 1920 ELEV. 17.487 FT. MONUMENTATION: Survey Disk VM#: 9159 AGENCY: PID#: SY0533 SETTING CLASSIFICATION: Concrete Abutment The bench mark is set vertically in the east face of the west concrete abutment of the South 15th Street bridge over the railroad yard, 22.5 feet (6.9 m) west of the west rail of the west track, 1.5 feet (0.5 m) south of the north end of the abutment 2 feet (0.6 m) higher than the track, and 1 foot (0.3 m) above the ground. BENCH MARK STAMPING: NO 23 1952 MONUMENTATION: Survey Disk VM#: 9160 AGENCY: PID#: SY0532 SETTING CLASSIFICATION: Concrete Foundation The bench mark is set in the top of a 2 x 2 foot (1x1 m) concrete piling, a former foundation for the dock, 100 feet (30 m) east of the centerline of Dock Street, and 38 feet (12 m) north of the north end of the Municipal Dock Building. BENCH MARK STAMPING: F 406 1965 MONUMENTATION: Survey Disk VM#: 9162 AGENCY: PID#: SY0535 SETTING CLASSIFICATION: Concrete Retaining Wall The bench mark is set in the top of the SW end of the SE concrete retaining wall for the 11th Street bridge over the Puyallup River, 4.5 feet (1.4 m) SW of the SE curb of East 11th Street, 4.5 feet (1.4 m) NE of the SW end of a guardrail, 0.5 foot (0.2 m) higher than the street, and level with the sidewalk.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 PUBLICATION DATE: 01/29/1988 Station ID: 9446545 SUPERCEDED DATE: 04/21/2003 Name: TACOMA, COMMENCEMENT BAY WASHINGTON NOAA Chart: 18453 Latitude: 47° 15.3' N USGS Quad: TACOMA NORTH Longitude: 122° 25.9' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: TIDAL BM 24 1974 MONUMENTATION: Survey Disk VM#: 9163 AGENCY: PID: SETTING CLASSIFICATION: Wall The bench mark is located on the parking lot wall of the Pacific National Bank of Washington, 135 feet (41 m) north of the corner of South 13th Street, 51.7 feet (15.8 m) east of the centerline of Pacific Avenue, and 3.5 feet (1.1 m) above the sidewalk.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 PUBLICATION DATE: 01/29/1988 Station ID: 9446545 SUPERCEDED DATE: 04/21/2003 Name: TACOMA, COMMENCEMENT BAY WASHINGTON NOAA Chart: 18453 Latitude: 47° 15.3' N USGS Quad: TACOMA NORTH Longitude: 122° 25.9' W T I D A L D A T U M S Tidal datums at TACOMA, COMMENCEMENT BAY based on: LENGTH OF SERIES: 9 MONTHS TIME PERIOD: APRIL 1977-FEBRUARY 1978 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 9447130 SEATTLE Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET: HIGHEST OBSERVED WATER LEVEL (12/15/1977) = 14.98 MEAN HIGHER HIGH WATER MHHW = 11.84 MEAN HIGH WATER MHW = 10.96 MEAN TIDE LEVEL MTL = 6.91 * NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 6.32 MEAN LOW WATER MLW = 2.86 MEAN LOWER LOW WATER MLLW = 0.00 LOWEST OBSERVED WATER LEVEL (06/02/1977) = -3.84 * NGVD reference based on adjustment of 1966 and NOS levels of 1977-78. North American Vertical Datum (NAVD88) Bench Mark Elevation Information In FEET above: Stamping or Designation MLLW MHW E 406 1965 23.63 12.67 F 11 1920 ELEV. 26.227 FT. 32.54 21.58 G 11 1920 ELEV. 17.487 FT. 23.78 12.82 NO 23 1952 21.52 10.56 F 406 1965 26.47 15.51 TIDAL BM 24 1974 85.28 74.32
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 PUBLICATION DATE: 01/29/1988 Station ID: 9446545 SUPERCEDED DATE: 04/21/2003 Name: TACOMA, COMMENCEMENT BAY WASHINGTON NOAA Chart: 18453 Latitude: 47° 15.3' N USGS Quad: TACOMA NORTH Longitude: 122° 25.9' W 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 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.