U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 08/06/1987
Station ID: 8723089 SUPERCEDED DATE: 04/21/2003
Name: BISCAYNE CREEK, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 25° 52.8' N
USGS Quad: NORTH MIAMI Longitude: 80° 9.8' W
To reach the tidal bench marks from the intersection of U.S. Highway 1 (Biscayne
Boulevard) and Broad Causeway (NE 123rd Street) in North Miami, proceed south on
U.S. Highway 1 for 0.5 mile (0.8 km) to the driveway leading to Lear School
(11211 Biscayne Boulevard). The bench marks are located near the school. The
tide gage and staff were located on the Lear School Pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: F 317 1970
MONUMENTATION: Survey Disk VM#: 5763
AGENCY: PID#: AC2352
SETTING CLASSIFICATION: Concrete Bulkhead
The bench mark is set flush in a drill hole in the top of the west end of a
concrete bulkhead, 36 feet (11 m) SW of the SW corner of the ladies restroom,
3.5 feet (1.1 m) east of the west end of the bulkhead, and level with the
ground.
BENCH MARK STAMPING: H 317 1970
MONUMENTATION: Survey Disk VM#: 5764
AGENCY: PID#: AC2347
SETTING CLASSIFICATION: Concrete Bulkhead
The bench mark is set flush in the top of a concrete bulkhead at the west end of
a curve in the bulkhead, 51 feet (16 m) SE of the SE corner of the sun room, and
level with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 08/06/1987
Station ID: 8723089 SUPERCEDED DATE: 04/21/2003
Name: BISCAYNE CREEK, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 25° 52.8' N
USGS Quad: NORTH MIAMI Longitude: 80° 9.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: J 317 1970
MONUMENTATION: Survey Disk VM#: 5765
AGENCY: PID#: AC2354
SETTING CLASSIFICATION: Concrete Bulkhead
The bench mark is set flush in a concrete bulkhead, 105 feet (32 m) NE of the NE
corner of the sun room, 8.7 feet (2.7 m) west of the NE corner of the seawall,
and level with the ground.
BENCH MARK STAMPING: K 317 1970
MONUMENTATION: Survey Disk VM#: 5766
AGENCY: PID#: AC2349
SETTING CLASSIFICATION: Copper-Clad Steel Rod
The bench mark is near the NE corner of a fence, 12 feet (4 m) south of the
centerline of the driveway, 3.8 feet (1.2 m) west of fence corner post, 0.5 foot
(0.2 m) north of the fence line, and 0.3 foot (0.1 m) north of a metal witness
post. The bench mark is crimped to a copper-clad steel rod driven an
unspecified depth to refusal, and encased in a steel pipe 1 foot (0.3 m) below
the disk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 08/06/1987
Station ID: 8723089 SUPERCEDED DATE: 04/21/2003
Name: BISCAYNE CREEK, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 25° 52.8' N
USGS Quad: NORTH MIAMI Longitude: 80° 9.8' W
T I D A L D A T U M S
Tidal datums at BISCAYNE CREEK, INTRACOASTAL WATERWAY based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: MAY 1970-APRIL 1971
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8723170 MIAMI BEACH
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (10/14/1970) = 3.54
MEAN HIGHER HIGH WATER MHHW = 2.41
MEAN HIGH WATER MHW = 2.34
MEAN TIDE LEVEL MTL = 1.24
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 0.74
MEAN LOW WATER MLW = 0.14
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (04/24/1970) = -0.65
* NGVD reference based on elevations published in Quad 250801, 1972, and NOS
leveling of 1982.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
F 317 1970 5.49 3.15
H 317 1970 5.45 3.11
J 317 1970 5.44 3.10
K 317 1970 5.85 3.51
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 08/06/1987
Station ID: 8723089 SUPERCEDED DATE: 04/21/2003
Name: BISCAYNE CREEK, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 25° 52.8' N
USGS Quad: NORTH MIAMI Longitude: 80° 9.8' 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.