U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8747145 PUBLICATION DATE: 02/26/2004
Name: MALLINI BAYOU SOUTH
MS
NOAA Chart: 11371 Latitude: 30° 18.7' N ( 30.31170)
USGS Quad: BAY ST. LOUIS Longitude: 89° 17.2' W ( -89.28670)
To reach the tidal bench marks from the east end of the U.S. Highway 90 bridge
over St. Louis Bay, proceed 0.6 km (0.4 mi) east and south on Highway 90 to its
intersection with Bayview Street, then proceed east on Bayview Street for 0.2 km
(0.1 mi) to its intersection with Mimosa Street, then turn right and proceed
south on Mimosa Street to the Tate residence, which is the second house on the
right. The bench marks are along Bayview and Mimosa Streets and near the Tate
residence. The tide gage and staff were located on the west side of the Tates
private dock.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7145 B 1978
DESIGNATION: 874 7145 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 10433
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 18.7' N ( 30.31170) LONGITUDE: 89° 17.2' W ( -89.28670)
The primary bench mark is a disk located at the SE corner of the Tates property,
50.44 m (165.5 ft) NE of bench mark 7145 A 1978, 37.28 m (122.3 ft) east of the
east corner of the Tates house, 9.51 m (31.2 ft) SW of the centerline of Mimosa
Street, and 3.14 m (10.3 ft) SW of power pole #PCo,8,59,GP,UO,LR,FT,535. The
bench mark is set 0.15 m (0.5 ft) below ground level, crimped to the top of a
steel rod driven 20.1 m (66 ft) 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 2 of 6
Station ID: 8747145 PUBLICATION DATE: 02/26/2004
Name: MALLINI BAYOU SOUTH
MS
NOAA Chart: 11371 Latitude: 30° 18.7' N ( 30.31170)
USGS Quad: BAY ST. LOUIS Longitude: 89° 17.2' W ( -89.28670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7145 A 1978
DESIGNATION: 874 7145 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 10432
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Boat ramp OPUS PID:
LATITUDE: 30° 18.7' N ( 30.31170) LONGITUDE: 89° 17.2' W ( -89.28670)
The bench mark is a disk set flush in the concrete boat ramp behind the Tate
residence, 8.75 m (28.7 ft) NW of a fence, 8.17 m (26.8 ft) NE of the east shore
of Mallini Bayou, and 3.29 m (10.8 ft) SW of the south corner of the Tates
house.
BENCH MARK STAMPING: 7145 D 1978
DESIGNATION: 874 7145 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 10435
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete bridge OPUS PID:
LATITUDE: 30° 18.7' N ( 30.31170) LONGITUDE: 89° 17.2' W ( -89.28670)
The bench mark is a disk set flush in the west end of the concrete bridge over
Mallini Bayou on Bayview Street, 90 m (296 ft) WNW of bench mark 7145 C 1978,
18.68 m (61.3 ft) SE of the SE corner of Barretts Marine building, and 3.51 m
(11.5 ft) north of the centerline of Bayview Street.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8747145 PUBLICATION DATE: 02/26/2004
Name: MALLINI BAYOU SOUTH
MS
NOAA Chart: 11371 Latitude: 30° 18.7' N ( 30.31170)
USGS Quad: BAY ST. LOUIS Longitude: 89° 17.2' W ( -89.28670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7145 E 1978
DESIGNATION: 874 7145 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 10436
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 18.7' N ( 30.31170) LONGITUDE: 89° 17.2' W ( -89.28670)
The bench mark is a disk located at the SE corner of the property at 202 Bayview
Street, 84 m (276 ft) ENE of bench mark 7145 C 1978, 18.50 m (60.7 ft) SE of the
SE corner of the house at 202 Bayview Street, 9.88 m (32.4 ft) east of a power
pole stamped GP,40,LR,FT,535, 8.26 m (27.1 ft) north of the centerline of
Bayview Street, and 1 m (3 ft) south of a 0.30 m (1.0 ft) diameter pine tree.
The bench mark is set 9 cm (0.3 ft) below ground level, crimped to the top of a
steel rod driven 16.5 m (54 ft) 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 4 of 6
Station ID: 8747145 PUBLICATION DATE: 02/26/2004
Name: MALLINI BAYOU SOUTH
MS
NOAA Chart: 11371 Latitude: 30° 18.7' N ( 30.31170)
USGS Quad: BAY ST. LOUIS Longitude: 89° 17.2' W ( -89.28670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: T 121 1938
DESIGNATION: T 121
MONUMENTATION: Bench Mark disk VM#: 10437
AGENCY: US Coast & Geodetic Survey
(USC&GS) IDB PID#: BH0926
SETTING CLASSIFICATION: Concrete post OPUS PID:
LATITUDE: 30° 18.6' N ( 30.31000) LONGITUDE: 89° 17.2' W ( -89.28670)
The bench mark is a disk set in a concrete post, located 4.3 km (2.7 mi) west
along the Louisville and Nashville Railroad from the crossing of Davis Avenue at
Pass Christian, 11 m (37 ft) north of the north rail, 9.60 m (31.5 ft) NW of the
west end of the first concrete pier north of the track, 4.72 m (15.5 ft) west of
the west edge of the U.S. Highway overpass for the track, 3.35 m (11.0 ft) west
of the west edge of a sidewalk, 0.61 m (2.0 ft) east of a metal witness post and
3 cm (0.1 ft) above ground level. NOTE: The mark is leaning to the SW and the
high point is on the numbers "21" in the stamping.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8747145 PUBLICATION DATE: 02/26/2004
Name: MALLINI BAYOU SOUTH
MS
NOAA Chart: 11371 Latitude: 30° 18.7' N ( 30.31170)
USGS Quad: BAY ST. LOUIS Longitude: 89° 17.2' W ( -89.28670)
T I D A L D A T U M S
Tidal datums at MALLINI BAYOU SOUTH based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: November 1978 - January 1979
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8747437 BAY WAVELAND YC, BAY ST. LOUIS
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.523
MEAN HIGH WATER MHW = 0.489
MEAN TIDE LEVEL MTL = 0.264
MEAN SEA LEVEL MSL = 0.262
MEAN LOW WATER MLW = 0.040
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7145 B 1978 1.485 0.996
7145 A 1978 1.225 0.736
7145 D 1978 2.748 2.259
7145 E 1978 2.422 1.933
T 121 1938 1.806 1.317
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8747145 PUBLICATION DATE: 02/26/2004
Name: MALLINI BAYOU SOUTH
MS
NOAA Chart: 11371 Latitude: 30° 18.7' N ( 30.31170)
USGS Quad: BAY ST. LOUIS Longitude: 89° 17.2' W ( -89.28670)
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 NGS's Integrated Data Base (IDB PID)
provides geodetic datum based on traditionally leveled and bluebooked ties to
the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/.
The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based
on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/.
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.