U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8746724 PUBLICATION DATE: 02/26/2004
Name: JOHNSON BAYOU
MS
NOAA Chart: 11371 Latitude: 30° 20.2' N ( 30.33670)
USGS Quad: PASS CHRISTIAN Longitude: 89° 13.5' W ( -89.22500)
To reach the tidal bench marks from the intersection of Menge Avenue and U.S.
Highway 90, proceed north on Menge Avenue for 1.6 km (1.0 mi) to the first paved
street on the left after crossing the bridge, then turn left and proceed west on
Jones Road for 0.6 km (0.4 mi) to its intersection with Morrow Drive, then turn
left and proceed south in Morrow Drive for 0.2 km (0.1 mi) to the last house on
the right (Borodenko residence). The bench marks are along Jones Road, Morrow
Street and on the grounds of the residence. The tide gage and staff were
located SW of the house on a small platform just offshore of the bulkhead.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6724 B 1978
DESIGNATION: 874 6724 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 10396
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 20.2' N ( 30.33670) LONGITUDE: 89° 13.5' W ( -89.22500)
The primary bench mark is a disk located at the SE corner of the Borodenko
property, 44.81 m (147.0 ft) east of bench mark 6724 A 1978, 34.63 m (113.6 ft)
ESE of the SE corner of the Borodenko house, 13.32 m (43.7 ft) SSE of power pole
#IPCD-665-GP-40-LR-FT, and 2.19 m (7.2 ft) north of a wooden bulkhead on Johnson
Bayou. The bench mark is set 9 cm (0.3 ft) below ground level, crimped to the
top of a stainless 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 2 of 6
Station ID: 8746724 PUBLICATION DATE: 02/26/2004
Name: JOHNSON BAYOU
MS
NOAA Chart: 11371 Latitude: 30° 20.2' N ( 30.33670)
USGS Quad: PASS CHRISTIAN Longitude: 89° 13.5' W ( -89.22500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6724 A 1978
DESIGNATION: 874 6724 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 10395
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete slab OPUS PID:
LATITUDE: 30° 20.2' N ( 30.33670) LONGITUDE: 89° 13.5' W ( -89.22500)
The bench mark is a disk set flush on the SE corner of a concrete slab, located
in the SW quadrant of the Borodenko property, 10.03 m (32.9 ft) north of a
wooden bulkhead at the edge of Johnson Bayou, 8.75 m (28.7 ft) south of the SW
corner of the Borodenko residence.
BENCH MARK STAMPING: 6724 C 1978
DESIGNATION: 874 6724 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 10397
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 20.2' N ( 30.33670) LONGITUDE: 89° 13.5' W ( -89.22500)
The bench mark is a disk located 73 m (239 ft) east of the centerline
intersection of Jones Avenue and Morrow Street, 9.94 m (32.6 ft) west of the
centerline of a dirt road leading north from Jones Avenue, 7.38 m (24.2 ft)
north of the centerline of Jones Avenue, and 2.32 m (7.6 ft) NW of power pole
#MRGO-666-GP-40-LP-FT- 540. The bench mark is set 0.15 m (0.5 ft) below ground
level, crimped to the top of a stainless steel rod driven 18.3 m (60 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 3 of 6
Station ID: 8746724 PUBLICATION DATE: 02/26/2004
Name: JOHNSON BAYOU
MS
NOAA Chart: 11371 Latitude: 30° 20.2' N ( 30.33670)
USGS Quad: PASS CHRISTIAN Longitude: 89° 13.5' W ( -89.22500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6724 D 1978
DESIGNATION: 874 6724 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 10398
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 20.2' N ( 30.33670) LONGITUDE: 89° 13.5' W ( -89.22500)
The bench mark is a disk located 82 m (270 ft) north of bench mark 6724 B 1978,
10 m (33 ft) west of the NW corner of a concrete block house, 6 m (20 ft) east
of the centerline of Morrow Street, and 0.46 m (1.5 ft) east of power pole
#7-55-GP-40-LR-FT-140. The bench mark is set 9 cm (0.3 ft) below ground level,
crimped to the top of a stainless steel rod driven 18.3 m (60 ft) to refusal,
and encased in a 4-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 6724 E 1978
DESIGNATION: 874 6724 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 10399
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 20.2' N ( 30.33670) LONGITUDE: 89° 13.5' W ( -89.22500)
The bench mark is a disk located on the SW corner of the property of Hartwig and
Mildice, 77 m (253 ft) north of bench mark 6724 D 1978, 51 m (167 ft) south of
the centerline intersection of Jones Avenue and Morrow Street, 14 m (46 ft) SW
of the SW corner of the house on the property of Hartwig and Mildice, and 5.55 m
(18.2 ft) east of the centerline of Morrow Street. The bench mark is set 12 cm
(0.4 ft) below ground level, crimped to the top of a stainless steel rod driven
18.3 m (60 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: 8746724 PUBLICATION DATE: 02/26/2004
Name: JOHNSON BAYOU
MS
NOAA Chart: 11371 Latitude: 30° 20.2' N ( 30.33670)
USGS Quad: PASS CHRISTIAN Longitude: 89° 13.5' W ( -89.22500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: X 134 1943
DESIGNATION: X 134
MONUMENTATION: Bench Mark disk VM#: 10400
AGENCY: US Coast & Geodetic Survey
(USC&GS) IDB PID#: BH0913
SETTING CLASSIFICATION: Concrete post OPUS PID:
LATITUDE: 30° 20.8' N ( 30.34670) LONGITUDE: 89° 13.0' W ( -89.21670)
The bench mark is a disk set in the top of a concrete post 0.08 m (0.25 ft)
below ground, located 2.49 km (1.55 mi) east along the Louisville and Nashville
railroad from the station at Pass Christian, then 2.1 km (1.3 mi) north along
Menge Avenue to the intersection of the avenue and a black top road leading
west, 5.94 m (19.5 ft) south of the centerline of the west road, 2.4 m (8 ft) NE
of an 18-inch pipe culvert under the west road, 1.10 m (3.6 ft) SW of power and
telephone pole #1101-S 102-11, and 0.46 m (1.5 ft) east of a wooden witness
post. NOTE: The bench mark is also 1.53 km (0.95 mi) south of the school at
Cuevas.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8746724 PUBLICATION DATE: 02/26/2004
Name: JOHNSON BAYOU
MS
NOAA Chart: 11371 Latitude: 30° 20.2' N ( 30.33670)
USGS Quad: PASS CHRISTIAN Longitude: 89° 13.5' W ( -89.22500)
T I D A L D A T U M S
Tidal datums at JOHNSON BAYOU based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: November 1978 - January 1979
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8747038 HENDERSON AVENUE BRIDGE, WOLF RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.572
MEAN HIGH WATER MHW = 0.524
MEAN TIDE LEVEL MTL = 0.290
MEAN SEA LEVEL MSL = 0.289
MEAN LOW WATER MLW = 0.055
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
6724 B 1978 1.124 0.600
6724 A 1978 1.542 1.018
6724 C 1978 2.889 2.365
6724 D 1978 2.240 1.716
6724 E 1978 2.191 1.667
X 134 1943 7.857 7.333
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8746724 PUBLICATION DATE: 02/26/2004
Name: JOHNSON BAYOU
MS
NOAA Chart: 11371 Latitude: 30° 20.2' N ( 30.33670)
USGS Quad: PASS CHRISTIAN Longitude: 89° 13.5' W ( -89.22500)
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.