U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 8735391 PUBLICATION DATE: 11/16/2020 Name: STATE HIGHWAY 163 BRIDGE, DOG RIVER AL NOAA Chart: 11376 Latitude: 30° 33.9' N ( 30.56517) USGS Quad: HOLLINGERS ISLAND Longitude: 88° 5.3' W ( -88.08800) From the intersection of I-10 and State Hwy 163 (Dauphin Island Pkwy) in Mobile, proceed south on Route 163 to the north end of the bridge over the Dog River, then turn right on Marina Drive and the Dog River Marina. The gauge is located on the bridge. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 5391 E 2011 DESIGNATION: 873 5391 E MONUMENTATION: Flange-encased Rod VM#: 20105 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBCL39 LATITUDE: 30° 34.2' N ( 30.57033) LONGITUDE: 88° 5.2' W ( -88.08642) The primary bench mark is a rod located at the foot of the John Roberts Peavy Bridge (Dog River) on the south bound side, between Highway 163 and Marina Drive in a grassy median, 18.75 m (61.5 ft) north of the north end of the bridge abutment, 8.30 m (27.2 ft) west of the west white line of the south bound lane of Highway 163, 6.25 m (20.5 ft) east of the centerline of Marina Drive, and 5.10 m (16.7 ft) west of a NOAA witness post. The bench mark is set flush with the ground, driven 27.7 m (90.9 ft) to refusal, and encased in a 5 inch (13 cm) PVC pipe with a concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 8735391 PUBLICATION DATE: 11/16/2020 Name: STATE HIGHWAY 163 BRIDGE, DOG RIVER AL NOAA Chart: 11376 Latitude: 30° 33.9' N ( 30.56517) USGS Quad: HOLLINGERS ISLAND Longitude: 88° 5.3' W ( -88.08800) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5391 A 2011 DESIGNATION: 873 5391 A MONUMENTATION: Tidal Station disk VM#: 20101 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Concrete bridge foundation OPUS PID: LATITUDE: 30° 34.0' N ( 30.56653) LONGITUDE: 88° 5.2' W ( -88.08742) The bench mark is a disk set flush in the SW corner of the seventh foundation south of the north end of the bridge, located in the SE corner of the Turner Marina property, 17.13 m (56.2 ft) NE of a light pole, 5.82 m (19.1 ft) east of the SE corner of the foundation, and 5.81 m (19.1 ft) south of the NW corner of the foundation. BENCH MARK STAMPING: 5391 B 2011 DESIGNATION: 873 5391 B MONUMENTATION: Tidal Station disk VM#: 20102 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Concrete bridge foundation OPUS PID: LATITUDE: 30° 34.0' N ( 30.56719) LONGITUDE: 88° 5.2' W ( -88.08719) The bench mark is a disk set flush in the SW corner of the fifth foundation south of the north end of the south bound side of the highway, 14.00 m (45.9 ft) east of the centerline of a road leading to Turner Marina, 5.76 m (18.9 ft) south of the NW corner of the foundation, 5.74 m (18.8 ft) west of the SE corner of the foundation.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 8735391 PUBLICATION DATE: 11/16/2020 Name: STATE HIGHWAY 163 BRIDGE, DOG RIVER AL NOAA Chart: 11376 Latitude: 30° 33.9' N ( 30.56517) USGS Quad: HOLLINGERS ISLAND Longitude: 88° 5.3' W ( -88.08800) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5391 C 2011 DESIGNATION: 873 5391 C MONUMENTATION: Tidal Station disk VM#: 20103 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Concrete bridge foundation OPUS PID: LATITUDE: 30° 34.1' N ( 30.56761) LONGITUDE: 88° 5.2' W ( -88.08711) The bench mark is a disk set flush under the bridge in the third foundation south (no. 28) of the north end of the south bound side, 7.48 m (24.5 ft) east of the centerline of Marina Drive, 5.73 m (18.8 ft) south of the NW corner of the foundation, and 5.72 m (18.8 ft) west of the SE corner of the foundation. BENCH MARK STAMPING: 5391 D 2011 DESIGNATION: 873 5391 D MONUMENTATION: Tidal Station disk VM#: 20104 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Concrete bridge foundation OPUS PID: LATITUDE: 30° 34.1' N ( 30.56828) LONGITUDE: 88° 5.2' W ( -88.08700) The bench mark is a disk set flush in the concrete foundation of the John Robert Peavy bridge on the first footer of the north end of the south bound side under the bridge, 9.07 m (29.8 ft) south of the centerline of a paved road leading to the Mobile Yacht Club, 7.83 m (25.7 ft) east of the centerline of Marina Drive, 5.16 m (16.9 ft) west of the NE corner of the abutement, and 5.16 m (16.9 ft) north of the SW corner of the abutement.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 8735391 PUBLICATION DATE: 11/16/2020 Name: STATE HIGHWAY 163 BRIDGE, DOG RIVER AL NOAA Chart: 11376 Latitude: 30° 33.9' N ( 30.56517) USGS Quad: HOLLINGERS ISLAND Longitude: 88° 5.3' W ( -88.08800) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5391 F 2011 DESIGNATION: 873 5391 F MONUMENTATION: Tidal Station disk VM#: 20106 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Bridge pavement OPUS PID: LATITUDE: 30° 33.9' N ( 30.56533) LONGITUDE: 88° 5.3' W ( -88.08794) The bench mark is a disk set flush in the Dog River bridge near the crest of the bridge and on the west side in the shoulder lane, 10.80 m (35.4 ft) south of a light pole, 2.10 m (6.9 ft) west of the west whiteline on the south bound lane, 0.70 m (2.3 ft) east of the west edge of the bridge.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 8735391 PUBLICATION DATE: 11/16/2020 Name: STATE HIGHWAY 163 BRIDGE, DOG RIVER AL NOAA Chart: 11376 Latitude: 30° 33.9' N ( 30.56517) USGS Quad: HOLLINGERS ISLAND Longitude: 88° 5.3' W ( -88.08800) T I D A L D A T U M S Tidal datums at STATE HIGHWAY 163 BRIDGE, DOG RIVER based on: LENGTH OF SERIES: 8 YEARS TIME PERIOD: July 2011 - June 2019 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8737048 MOBILE STATE DOCKS, MOBILE RIVER Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (10/08/2017) = 1.880 MEAN HIGHER HIGH WATER MHHW = 0.500 MEAN HIGH WATER MHW = 0.474 MEAN TIDE LEVEL MTL = 0.252 MEAN SEA LEVEL MSL = 0.246 MEAN LOW WATER MLW = 0.029 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (09/16/2020) = -1.212 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 5391 E 2011 1.180 0.706 5391 A 2011 2.256 1.782 5391 B 2011 2.242 1.768 5391 C 2011 2.257 1.783 5391 D 2011 2.110 1.636 5391 F 2011 25.738 25.264
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 8735391 PUBLICATION DATE: 11/16/2020 Name: STATE HIGHWAY 163 BRIDGE, DOG RIVER AL NOAA Chart: 11376 Latitude: 30° 33.9' N ( 30.56517) USGS Quad: HOLLINGERS ISLAND Longitude: 88° 5.3' W ( -88.08800) 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.