U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 03/30/1983
Station ID: 8747739 SUPERCEDED DATE: 04/21/2003
Name: JOURDAN RIVER ENTRANCE
MISSISSIPPI
NOAA Chart: 11371 Latitude: 30° 20.2' N
USGS Quad: BAY ST. LOUIS Longitude: 89° 22.0' W
To reach the tidal bench marks from the intersection of Blue Meadow Road and
U.S. Highway 90 in Bay St. Louis, proceed north on Blue Meadow Road for 1.6
miles (2.6 km) to an intersection, then turn right onto Harrison Road and
continue north for 0.4 mile (0.6 km) to the end of the road. The bench marks
are located south of the gage site along Harrison Road.The tide gage and staff
were located on the westernmost of several abandoned pilings NW of the end of
Harrison Street.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7739 A 1978
MONUMENTATION: Survey Disk VM#: 10443
AGENCY: PID:
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is located on the Hilly property, 109 feet (33 m) SW of the south
bank of the Jourdan River, 9 feet (3 m) west of a driveway, and 1 foot (0.3 m)
NE of a fence line. The bench mark is 0.5 foot (0.2 m) below ground level,
crimped to a stainless steel rod driven 60 feet (18 m) to refusal, and encased
in a 4-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 7739 B 1978
MONUMENTATION: Survey Disk VM#: 10444
AGENCY: PID:
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is 211 feet (64 m) SE of Bench Mark 7739A 1978, 100.5 feet (30.6
m) NW of the centerline of Harrison Road, and 65.0 feet (19.8 m) west of power
pole #CEPA-OP-UO-F-89-6P-OP. The bench mark is 0.5 foot (0.2 m) below ground
level, crimped to a stainless steel rod driven 36 feet (11 m) 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 5
PUBLICATION DATE: 03/30/1983
Station ID: 8747739 SUPERCEDED DATE: 04/21/2003
Name: JOURDAN RIVER ENTRANCE
MISSISSIPPI
NOAA Chart: 11371 Latitude: 30° 20.2' N
USGS Quad: BAY ST. LOUIS Longitude: 89° 22.0' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7739 C 1978
MONUMENTATION: Survey Disk VM#: 10445
AGENCY: PID:
SETTING CLASSIFICATION: Pavement
The bench mark is 152.7 feet (46.5 m) east of Bench Mark 7739B 1978, 48.0 feet
(14.6 m) east of the centerline of Harrison Road, 27.7 feet (8.4 m) ENE of power
pole #CEPA-CP-PI-SPP, and 2.8 feet (0.9 m) west of the SW corner of a block
house. The bench mark is set flush in the concrete driveway in front of the
house.
BENCH MARK STAMPING: 7739 D 1978
MONUMENTATION: Survey Disk VM#: 10446
AGENCY: PID:
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is 215 feet (66 m) south of Bench Mark 7739C 1978, 22 feet (7 m)
east of the centerline of Harrison Road, 17 feet (5 m) north of the centerline
of the Smiths driveway, 2.3 feet (0.7 m) SW of power pole #11, and 1.7 feet (0.5
m) SE of the NW corner fence post of the Smiths property. The bench mark is 0.4
foot (0.1 m) below ground level, crimped to a stainless steel rod driven 54 feet
(16 m) 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 5
PUBLICATION DATE: 03/30/1983
Station ID: 8747739 SUPERCEDED DATE: 04/21/2003
Name: JOURDAN RIVER ENTRANCE
MISSISSIPPI
NOAA Chart: 11371 Latitude: 30° 20.2' N
USGS Quad: BAY ST. LOUIS Longitude: 89° 22.0' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7739 E 1978
MONUMENTATION: Survey Disk VM#: 10447
AGENCY: PID:
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is 301 feet (92 m) south of Bench Mark 7739D 1978, 60 feet (18 m)
WNW of the NW corner of a frame house, 23 feet (7 m) east of the centerline of
Harrison Road, and 1.5 feet (0.5 m) west of power pole #7. The bench mark is
0.5 feet (0.2 m) below ground level, crimped to a stainless steel rod driven 54
feet (16 m) 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 5
PUBLICATION DATE: 03/30/1983
Station ID: 8747739 SUPERCEDED DATE: 04/21/2003
Name: JOURDAN RIVER ENTRANCE
MISSISSIPPI
NOAA Chart: 11371 Latitude: 30° 20.2' N
USGS Quad: BAY ST. LOUIS Longitude: 89° 22.0' W
T I D A L D A T U M S
Tidal datums at JOURDAN RIVER ENTRANCE based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: NOVEMBER 1978-JANUARY 1979
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8747437 BAY WAVELAND YACHT CLUB, BAY ST. LOUIS
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (01/01/1979) = 2.91
MEAN HIGHER HIGH WATER MHHW = 1.82
MEAN HIGH WATER MHW = 1.62
MEAN TIDE LEVEL MTL = 0.91
MEAN LOW WATER MLW = 0.20
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (01/24/1979) = -2.34
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
7739 A 1978 3.02 1.40
7739 B 1978 3.52 1.90
7739 C 1978 6.80 5.18
7739 D 1978 3.81 2.19
7739 E 1978 4.67 3.05
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 03/30/1983
Station ID: 8747739 SUPERCEDED DATE: 04/21/2003
Name: JOURDAN RIVER ENTRANCE
MISSISSIPPI
NOAA Chart: 11371 Latitude: 30° 20.2' N
USGS Quad: BAY ST. LOUIS Longitude: 89° 22.0' 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.