U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 4 PUBLICATION DATE: 08/07/1985 Station ID: 8726614 SUPERCEDED DATE: 04/21/2003 Name: ALAFIA RIVER NORTH FLORIDA NOAA Chart: 11412 Latitude: 27° 52.2' N USGS Quad: BRANDON Longitude: 82° 19.2' W To reach the tidal bench marks from the intersection of Riverview Drive and U.S. Highway 301 in Riverview, proceed south on U.S. Highway 301 to Glen D. Litkes Auto Salvage Company. The bench marks are located near the Salvage Company. The tide gage and staff were located on the wooden dock behind the Salvage Company. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 6614 A 1977 MONUMENTATION: Survey Disk VM#: 6623 AGENCY: PID#: AG7481 SETTING CLASSIFICATION: Concrete Bridge Abutment The bench mark is at the NE corner of the bridge over the Alafia River, 26.4 feet (8.0 m) east of the centerline of U.S. Highway 301, 6 feet (2 m) east of the east edge of the bridge, and 1.4 feet (0.4 m) west of the west edge of the abutment foundation. BENCH MARK STAMPING: 6614 B 1977 MONUMENTATION: Survey Disk VM#: 6624 AGENCY: PID#: AG7480 SETTING CLASSIFICATION: Bridge Abutment The bench mark is at the NW corner of the bridge over the Alafia River, 21.5 feet (6.6 m) west of the centerline of U.S. Highway 301, 6.1 feet (1.9 m) east of the west end of the bridge abutment wingwall, and 0.7 feet (0.2 m) west of the bridge rail.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 4 PUBLICATION DATE: 08/07/1985 Station ID: 8726614 SUPERCEDED DATE: 04/21/2003 Name: ALAFIA RIVER NORTH FLORIDA NOAA Chart: 11412 Latitude: 27° 52.2' N USGS Quad: BRANDON Longitude: 82° 19.2' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 6614 C 1977 MONUMENTATION: Survey Disk VM#: 6625 AGENCY: PID#: AG7482 SETTING CLASSIFICATION: Concrete Post The bench mark is just NE of the north end of the bridge, 61.5 feet (18.7 m) NE of the SE corner of a wood frame house, 46.8 feet (14.3 m) west of a fence, 45 feet (14 m) north of north river bank, 41.5 feet (12.6 m) NNE of the north end of a wooden walkway to a dock, 1.7 feet (0.5 m) south of the SE corner of a tin building, and 1.3 feet (0.4 m) south of a witness post. The bench mark is set in the top of a concrete post. BENCH MARK STAMPING: 6614 E 1977 MONUMENTATION: Survey Disk VM#: 6626 AGENCY: PID#: AG7479 SETTING CLASSIFICATION: Concrete Curb The bench mark is located in front of Glen Litkes property, 40.2 feet (12.3 m) SW of the SW corner of a bike parts supply building, 37 feet (11 m) SW of a power pole, and 26.8 feet (8.2 m) east of the centerline of U.S. Highway 301. BENCH MARK STAMPING: 6614 F 1977 MONUMENTATION: Survey Disk VM#: 6627 AGENCY: PID#: AG7478 SETTING CLASSIFICATION: Concrete Curb The bench mark is located at the intersection of U.S. Highway 301 and Riverview Drive, 41 feet (12 m) north of the centerline of Riverview Drive, 32.1 feet (9.8 m) east of the centerline of U.S. Highway 301, 23.6 feet (7.2 m) west of a telephone pole, and 9 feet (3 m) WSW of traffic light pole # 0735.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 4 PUBLICATION DATE: 08/07/1985 Station ID: 8726614 SUPERCEDED DATE: 04/21/2003 Name: ALAFIA RIVER NORTH FLORIDA NOAA Chart: 11412 Latitude: 27° 52.2' N USGS Quad: BRANDON Longitude: 82° 19.2' W T I D A L D A T U M S Tidal datums at ALAFIA RIVER NORTH 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 Lower Low Water (MLLW), in FEET: HIGHEST OBSERVED WATER LEVEL (01/10/1977) = 3.59 MEAN HIGHER HIGH WATER MHHW = 2.75 MEAN HIGH WATER MHW = 2.48 MEAN TIDE LEVEL MTL = 1.45 MEAN LOW WATER MLW = 0.42 MEAN LOWER LOW WATER MLLW = 0.00 LOWEST OBSERVED WATER LEVEL (02/02/1977) = -1.27 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In FEET above: Stamping or Designation MLLW MHW 6614 A 1977 15.28 12.80 6614 B 1977 20.32 17.84 6614 C 1977 7.16 4.68 6614 E 1977 14.56 12.08 6614 F 1977 16.78 14.30
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 4 PUBLICATION DATE: 08/07/1985 Station ID: 8726614 SUPERCEDED DATE: 04/21/2003 Name: ALAFIA RIVER NORTH FLORIDA NOAA Chart: 11412 Latitude: 27° 52.2' N USGS Quad: BRANDON Longitude: 82° 19.2' 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.