U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 4 PUBLICATION DATE: 02/13/1988 Station ID: 8726632 SUPERCEDED DATE: 04/21/2003 Name: ARCHIE CREEK, HILLSBOROUGH BAY FLORIDA NOAA Chart: 11413 Latitude: 27° 52.9' N USGS Quad: TAMPA Longitude: 82° 23.8' W To reach the tidal bench marks from the south end of the U.S. Highway 41 bridge over Palm River, proceed south on U.S. Highway 41 for 4.6 miles (7.4 km) to the bridge over Archie Creek. The bench marks are located along U.S. Highway 41. The tide gage and staff were located on the west side of the bridge. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 6632 A 1977 MONUMENTATION: Survey Disk VM#: 6633 AGENCY: PID#: AG7469 SETTING CLASSIFICATION: Concrete Culvert The bench mark is set flush in a concrete culvert, 60 feet (18 m) NW of the SE end of the culvert headwall, 29 feet (9 m) SW of the centerline of the southbound lane of U.S. Highway 41, 3 feet (1 m) SE of the NW end of the culvert headwall, and 2 feet (1 m) below the highway. BENCH MARK STAMPING: 6632 B 1977 MONUMENTATION: Survey Disk VM#: 6634 AGENCY: PID#: AG7468 SETTING CLASSIFICATION: Concrete Drain The bench mark is set flush in a 6 x 7-foot (2 x 2 m) concrete drain box with an iron gate, 65.0 feet (19.8 m) ESE of Bench Mark 6632 A 1977, 36.7 feet (11.2 m) SW of the centerline of the northbound lane of U.S. Highway 41, 29.5 feet (9.0 m) NE of the centerline of the southbound lane, and 2 feet (1 m) below the highway.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 4 PUBLICATION DATE: 02/13/1988 Station ID: 8726632 SUPERCEDED DATE: 04/21/2003 Name: ARCHIE CREEK, HILLSBOROUGH BAY FLORIDA NOAA Chart: 11413 Latitude: 27° 52.9' N USGS Quad: TAMPA Longitude: 82° 23.8' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 6632 C 1977 MONUMENTATION: Survey Disk VM#: 6635 AGENCY: PID#: AG7467 SETTING CLASSIFICATION: Concrete Culvert The bench mark is set flush in a concrete culvert, 69.5 feet (21.2 m) ESE of Bench Mark 6632 B 1977, 26.5 feet (8.1 m) NE of the centerline of the northbound lane of U.S. Highway 41, 0.8 foot (0.2 m) NW of the SE end of the culvert headwall, and 2 feet (1 m) below the highway. BENCH MARK STAMPING: 6632 E 1977 MONUMENTATION: Survey Disk VM#: 6636 AGENCY: PID#: AG7466 SETTING CLASSIFICATION: Concrete Monument The bench mark is set in the top of a concrete monument, 575 feet (175 m) south of Bench Mark 6632 C 1977, 78 feet (24 m) NE of the centerline of the northbound lane of U.S. Highway 41, 3.5 feet (1.1 m) SW of the SW end of a billboard sign with a witness sign attached, 4 feet (1 m) below the highway, and level with the ground. BENCH MARK STAMPING: 6632 F 1977 MONUMENTATION: Survey Disk VM#: 6637 AGENCY: PID#: AG7465 SETTING CLASSIFICATION: Copper-clad Steel Rod The bench mark is 345 feet (105 m) SSW of Bench Mark 6632 E 1977, 33.5 feet (10.2 m) SW of the centerline of the northbound lane of U.S. Highway 41, 33.5 feet (10.2 m) NE of the centerline of the southbound lane, and 6 feet (2 m) north of the north curb of the median cross-over road. The bench mark is level with the highway, crimped to a copper-clad steel rod driven an unspecified depth to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 4 PUBLICATION DATE: 02/13/1988 Station ID: 8726632 SUPERCEDED DATE: 04/21/2003 Name: ARCHIE CREEK, HILLSBOROUGH BAY FLORIDA NOAA Chart: 11413 Latitude: 27° 52.9' N USGS Quad: TAMPA Longitude: 82° 23.8' W T I D A L D A T U M S Tidal datums at ARCHIE CREEK, HILLSBOROUGH BAY based on: LENGTH OF SERIES: 2 MONTHS TIME PERIOD: MARCH-APRIL 1977 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 8726537 APOLLO BEACH Elevations of tidal datums referred to Mean High Water (MHW), in FEET: HIGHEST OBSERVED WATER LEVEL (12/21/1976) = 1.53 MEAN HIGHER HIGH WATER MHHW = 0.18 MEAN HIGH WATER MHW = 0.00 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In FEET above: Stamping or Designation MHW 6632 A 1977 5.09 6632 B 1977 4.96 6632 C 1977 4.98 6632 E 1977 2.71 6632 F 1977 8.79 Foot Notes: The datums were computed by the NOS Direct Method due to flat low waters.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 4 PUBLICATION DATE: 02/13/1988 Station ID: 8726632 SUPERCEDED DATE: 04/21/2003 Name: ARCHIE CREEK, HILLSBOROUGH BAY FLORIDA NOAA Chart: 11413 Latitude: 27° 52.9' N USGS Quad: TAMPA Longitude: 82° 23.8' 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.