U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8737373 PUBLICATION DATE: 12/01/2011
Name: LOWER BRYANT LANDING, TENSAW RIVER
AL
NOAA Chart: 11376 Latitude: 30° 58.7' N ( 30.97830)
USGS Quad: BAY MINETTE Longitude: 87° 52.4' W ( -87.87330)
To reach the tidal bench marks from I-65 North, take exit 31 (the Stockton exit)
to 225 N and proceed 3.7 km (2.3 mi) on 225 N to South Lower Bryant Road and
turn right and travel 0.3 km (0.2 mi) to the edge of Tensaw River. Bench marks
are located along the road and the river and the tide station is located on the
boat dock.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7373 A 2004
DESIGNATION: 873 7373 A
MONUMENTATION: Flange-encased Rod VM#: 17645
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 30° 58.7' N ( 30.97830) LONGITUDE: 87° 52.3' W ( -87.87170)
The primary bench mark is located on the west side of the road near the NOAA
tide station, 36.58 m (120.0 ft) north of a power pole # 16 with a transformer,
13.20 m (43.3 ft) west of the centerline of the road, 10.93 m (35.9 ft) south of
the south side of a stairway leading to a wooden dock, 8.85 m (29.0 ft) east of
east edge of a wooden bulkhead, and 0.30 m (1.0 ft) east of a NOAA witness post.
The mark being the top of a stainless steel rod, driven to 13.4 m (44 ft) to
refusal and encased with a concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8737373 PUBLICATION DATE: 12/01/2011
Name: LOWER BRYANT LANDING, TENSAW RIVER
AL
NOAA Chart: 11376 Latitude: 30° 58.7' N ( 30.97830)
USGS Quad: BAY MINETTE Longitude: 87° 52.4' W ( -87.87330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7373 B 2004
DESIGNATION: 873 7373 B
MONUMENTATION: Flange-encased Rod VM#: 17646
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 30° 58.6' N ( 30.97670) LONGITUDE: 87° 52.4' W ( -87.87330)
The bench mark is located in a grassy area by the river bank, 40.45 m (132.7 ft)
SW of a light pole with meter, 19.15 m (62.8 ft) NNE of power pole number 3 with
a transformer, 18.50 m (60.7 ft) NW of the centerline of the road, 5.82 m (19.1
ft) SE of the riverbank and across the road from trailer number 411. The mark
being the top of a stainless steel rod, driven to 12.2 m (40 ft) to refusal and
encased with a concrete kickblock.
BENCH MARK STAMPING: 7373 C 2004
DESIGNATION: 873 7373 C
MONUMENTATION: Flange-encased Rod VM#: 17647
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 30° 58.7' N ( 30.97830) LONGITUDE: 87° 52.3' W ( -87.87170)
The bench mark is located near the boat ramp, 26.40 m (86.6 ft) SSW of the west
side of the boat ramp, 17.15 m (56.3 ft) north of a light pole number 48, 15.00
m (49.2 ft) SSE of the river bank, 10.69 m (35.1 ft) NNW of the centerline of
the road. The mark being the top of a stainless steel rod, driven to 14.6 m (48
ft) to refusal and encased with a concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8737373 PUBLICATION DATE: 12/01/2011
Name: LOWER BRYANT LANDING, TENSAW RIVER
AL
NOAA Chart: 11376 Latitude: 30° 58.7' N ( 30.97830)
USGS Quad: BAY MINETTE Longitude: 87° 52.4' W ( -87.87330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7373 D 2004
DESIGNATION: 873 7373 D
MONUMENTATION: Flange-encased Rod VM#: 17648
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 30° 58.8' N ( 30.98000) LONGITUDE: 87° 52.3' W ( -87.87170)
The bench mark is located on South Lower Bryant Road, 60.65 m (199.0 ft) NE of
the NE edge of a boat ramp, 11.57 m (37.96 ft) north of a power pole number 11
with transformer, 3.75 m (12.3 ft) SE of the edge of the river bank, and 0.3 m
(1.0 ft) east of a NOAA witness post. The mark being the top of a stainless
steel rod, driven to 14.6 m (48 ft) to refusal and encased with a concrete
kickblock.
BENCH MARK STAMPING: 7373 E 2004
DESIGNATION: 873 7373 E
MONUMENTATION: Flange-encased Rod VM#: 17649
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 30° 58.8' N ( 30.98000) LONGITUDE: 87° 52.2' W ( -87.87000)
The bench mark is located on South Lower Bryant Road, 47.15 m (154.7 ft) SE of
power pole number 216 with a light, 46.20 m (151.6 ft) south of a power pole
number 25 with a transformer, 23.57 m (77.3 ft) west of the centerline of the
road, 20.68 m ( 67.8 ft) north of a power pole number 26 with a transformer, and
0.30 m (1.0 ft) SE of a NOAA witness post. The mark being the top of a stainless
steel rod, driven to 19.5 m (64 ft) to refusal and encased with a concrete
kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8737373 PUBLICATION DATE: 12/01/2011
Name: LOWER BRYANT LANDING, TENSAW RIVER
AL
NOAA Chart: 11376 Latitude: 30° 58.7' N ( 30.97830)
USGS Quad: BAY MINETTE Longitude: 87° 52.4' W ( -87.87330)
T I D A L D A T U M S
Tidal datums at LOWER BRYANT LANDING, TENSAW RIVER based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: August 2006 - July 2007
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8735180 DAUPHIN ISLAND, MOBILE BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (09/16/2004) = 1.445
MEAN HIGHER HIGH WATER MHHW = 0.536
MEAN HIGH WATER MHW = 0.511
MEAN SEA LEVEL MSL = 0.282
MEAN TIDE LEVEL MTL = 0.267
MEAN LOW WATER MLW = 0.022
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (11/17/2005) = -0.701
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7373 A 2004 3.879 3.368
7373 B 2004 3.224 2.713
7373 C 2004 2.422 1.911
7373 D 2004 3.333 2.822
7373 E 2004 5.843 5.332
Foot Notes:
Bench mark 7373 D 2004 is based on one differential leveling connection and do
not meet the quality control standards of the NOS. Therefore, caution should be
used when deriving elevations for this mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8737373 PUBLICATION DATE: 12/01/2011
Name: LOWER BRYANT LANDING, TENSAW RIVER
AL
NOAA Chart: 11376 Latitude: 30° 58.7' N ( 30.97830)
USGS Quad: BAY MINETTE Longitude: 87° 52.4' W ( -87.87330)
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.