U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 02/27/1984
Station ID: 8726539 SUPERCEDED DATE: 04/21/2003
Name: NEWMAN BRANCH CREEK, HILLSBOROUGH BAY
FLORIDA
NOAA Chart: 11413 Latitude: 27° 47.0' N
USGS Quad: GIBSONTON Longitude: 82° 24.4' W
To reach the tidal bench marks from Apollo Beach Post Office travel 3.5 miles
(5.6 km) west on Apollo Beach Boulevard to Dickman Drive, then north on Dickman
Drive 0.5 miles (0.8 km) to Newman Branch Creek. The bench marks are in the
vicinity of Dickman Drive and Newman Branch Creek. The tide gage and staff were
on the end of a small pier west of Dickman Drive bridge over Newman Branch
Creek.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6539 A 1977
MONUMENTATION: Survey Disk VM#: 6552
AGENCY: PID#: AG7597
SETTING CLASSIFICATION: Copper-Clad Steel Rod
The bench mark is located west of Dickman Drive near Newman Branch, 230 feet (70
m) west of the NW corner of the bridge over the creek, 0.8 feet (0.2 m) south of
a witness post, set on top of a rod driven to 40 feet (12.2 m) and encased in a
pipe projecting 0.2 feet (0.06 m).
BENCH MARK STAMPING: 6539 B 1977
MONUMENTATION: Survey Disk VM#: 6553
AGENCY: PID#: AG7596
SETTING CLASSIFICATION: Concrete Bridge Abutment
The bench mark is located west of Dickman Drive near Newman Branch, 240 feet
(73.2 m) east of Bench Mark 6539 A 1977, 61 feet (18.6 m) north of the south end
of the bridge, 21 feet (6.4 m) west of the centerline of Dickman Drive and 1
foot (0.3 m) below the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 02/27/1984
Station ID: 8726539 SUPERCEDED DATE: 04/21/2003
Name: NEWMAN BRANCH CREEK, HILLSBOROUGH BAY
FLORIDA
NOAA Chart: 11413 Latitude: 27° 47.0' N
USGS Quad: GIBSONTON Longitude: 82° 24.4' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6539 C 1977
MONUMENTATION: Survey Disk VM#: 6554
AGENCY: PID#: AG7598
SETTING CLASSIFICATION: Concrete Bridge Abutment
The bench mark is located east of Dickman Drive near the SE corner of the bridge
over Newman Branch Creek, 75 feet (22.9 m) SE of Bench Mark 6539 B 1977, 20 feet
(6.1 m) east of the centerline of Dickman Drive, 2.2 feet (0.7 m) east of the SE
corner of the bridge and 1 foot (0.3 m) below the road.
BENCH MARK STAMPING: 6539 E 1977
MONUMENTATION: Survey Disk VM#: 6555
AGENCY: PID#: AG7599
SETTING CLASSIFICATION: Concrete Bridge Abutment
The bench mark is located west of Dickman Drive set in the abutment of a small
bridge over a canal, 0.3 mile (0.5 km) south of Newman Branch Bridge, 61 feet
(18.6 m) north of south end of the bridge over the canal, 20 feet (6.1 m) west
of the centerline of Dickman Drive, 2 feet (0.6 m) SW of NE corner of bridge and
1 foot (0.3 m) below the road.
BENCH MARK STAMPING: 6539 F 1977
MONUMENTATION: Survey Disk VM#: 6556
AGENCY: PID#: AG7600
SETTING CLASSIFICATION: Concrete Bridge Abutment
The bench mark is located east of Dickman Drive set in the abutment of a small
bridge over a canal, 0.3 mile (0.5 km) south of Newman Branch Bridge, 75 feet
(22.9 m) SE of Bench Mark 6539 E 1977, 20 feet (6.1 m) east of the centerline of
Dickman Drive, 2.2 feet (0.7 m) east of the SE corner of the bridge and 1 foot
(0.3 m) below the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 02/27/1984
Station ID: 8726539 SUPERCEDED DATE: 04/21/2003
Name: NEWMAN BRANCH CREEK, HILLSBOROUGH BAY
FLORIDA
NOAA Chart: 11413 Latitude: 27° 47.0' N
USGS Quad: GIBSONTON Longitude: 82° 24.4' W
T I D A L D A T U M S
Tidal datums at NEWMAN BRANCH CREEK, HILLSBOROUGH BAY based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: APRIL-JUNE 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 (06/02/1977) = 3.67
MEAN HIGHER HIGH WATER MHHW = 2.54
MEAN HIGH WATER MHW = 2.26
MEAN TIDE LEVEL MTL = 1.34
MEAN LOW WATER MLW = 0.42
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (04/08/1977) = -0.96
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
6539 A 1977 3.27 1.01
6539 B 1977 10.08 7.82
6539 C 1977 10.10 7.84
6539 E 1977 10.10 7.84
6539 F 1977 10.17 7.91
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 02/27/1984
Station ID: 8726539 SUPERCEDED DATE: 04/21/2003
Name: NEWMAN BRANCH CREEK, HILLSBOROUGH BAY
FLORIDA
NOAA Chart: 11413 Latitude: 27° 47.0' N
USGS Quad: GIBSONTON Longitude: 82° 24.4' 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.