U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 8747819 PUBLICATION DATE: 03/09/2004 Name: WATTS BAYOU, JOURDAN RIVER MS NOAA Chart: 11371 Latitude: 30° 19.7' N ( 30.32830) USGS Quad: BAY ST. LOUIS Longitude: 89° 22.4' W ( -89.37330) To reach the tidal bench marks from the intersection of Blue Meadow Road and U.S. Highway 90 in Bay St. Louis, proceed 2.9 km (1.8 mi) NW on Blue Meadow Road to its intersection with Stewart Road (just before Merls Tavern), then turn right and proceed 0.6 km (0.4 mi) north on Stewart Road, across Watts Bayou, to Mole Drive, the first paved road on the right, then turn right and proceed 0.6 km (0.4 mi) north on Mole Drive to the Plove residence at the NE corner of the traffic turnaround. The bench marks are located in the vicinity of the Mole Drive turnaround. The tide gage and staff were located at the ends of the two northernmost of four docks NE of the Plove residence. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 7819 A 1978 DESIGNATION: 874 7819 A TIDAL MONUMENTATION: Tidal Station disk VM#: 10449 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 30° 19.7' N ( 30.32830) LONGITUDE: 89° 22.4' W ( -89.37330) The primary bench mark is a disk located 20.85 m (68.4 ft) north of the north corner of the Plove residence, 19.08 m (62.6 ft) NNE of the NE corner of the pool foundation, and 2 m (7 ft) SSW of a canal leading to Watts Bayou. The bench mark is set 12 cm (0.4 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: 8747819 PUBLICATION DATE: 03/09/2004 Name: WATTS BAYOU, JOURDAN RIVER MS NOAA Chart: 11371 Latitude: 30° 19.7' N ( 30.32830) USGS Quad: BAY ST. LOUIS Longitude: 89° 22.4' W ( -89.37330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7819 B 1978 DESIGNATION: 874 7819 B TIDAL MONUMENTATION: Tidal Station disk VM#: 10450 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Pool foundation OPUS PID: LATITUDE: 30° 19.7' N ( 30.32830) LONGITUDE: 89° 22.4' W ( -89.37330) The bench mark is a disk set flush on the west corner of the pool foundation at the Plove residence, 33 m (109 ft) SW of the canal leading to Watts Bayou, 31 m (102 ft) SW of bench mark 7819 A 1978, and 7.99 m (26.2 ft) NW of the west corner of the Plove residence. BENCH MARK STAMPING: 7819 D 1978 DESIGNATION: 874 7819 D TIDAL MONUMENTATION: Tidal Station disk VM#: 10452 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Driveway abutment OPUS PID: LATITUDE: 30° 19.7' N ( 30.32830) LONGITUDE: 89° 22.4' W ( -89.37330) The bench mark is a disk set flush on an abutment on the driveway to the Darrow residence located on the east side of the Mole Drive turnaround, 55 m (182 ft) SE of bench mark 7819 C 1978, 25.36 m (83.2 ft) west of the NW corner of the Darrow residence, 16.95 m (55.6 ft) north of power pole #CFP- P-56-SPC-0-735, and 5 m (18 ft) east of the centerline of Mole Drive.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 8747819 PUBLICATION DATE: 03/09/2004 Name: WATTS BAYOU, JOURDAN RIVER MS NOAA Chart: 11371 Latitude: 30° 19.7' N ( 30.32830) USGS Quad: BAY ST. LOUIS Longitude: 89° 22.4' W ( -89.37330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7819 E 1978 DESIGNATION: 874 7819 E TIDAL MONUMENTATION: Tidal Station disk VM#: 10453 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 30° 19.7' N ( 30.32830) LONGITUDE: 89° 22.4' W ( -89.37330) The bench mark is a disk near the south end of the Mole Drive turnaround, 107 m (351 ft) south of bench mark 7819 D 1978, 37.12 m (121.8 ft) SW of the south corner of the Kelly residence, 6 m (21 ft) WSW of the centerline of Mole Drive, and 4 m (12 ft) NNE of a canal. The bench mark is set 12 cm (0.4 ft) below ground level, crimped to the top of a stainless steel rod driven 12.8 m (42 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: 8747819 PUBLICATION DATE: 03/09/2004 Name: WATTS BAYOU, JOURDAN RIVER MS NOAA Chart: 11371 Latitude: 30° 19.7' N ( 30.32830) USGS Quad: BAY ST. LOUIS Longitude: 89° 22.4' W ( -89.37330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: R 190 1955 DESIGNATION: R 190 MONUMENTATION: Bench Mark disk VM#: 10454 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: BH0942 SETTING CLASSIFICATION: Concrete head wall OPUS PID: LATITUDE: 30° 19.2' N ( 30.32000) LONGITUDE: 89° 20.5' W ( -89.34170) The bench mark is a disk set on the top of the NE end of the NW concrete head wall for a 1.83 m (6.0 ft) culvert located under a service road and the highway, 26.82 m (88.0 ft) NW of and across a service road from the center line of the westbound lane of the highway, 6.40 m (21.0 ft) NW of the center line of the service road and 0.61 m (2.0 ft) below the level of the highway.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 8747819 PUBLICATION DATE: 03/09/2004 Name: WATTS BAYOU, JOURDAN RIVER MS NOAA Chart: 11371 Latitude: 30° 19.7' N ( 30.32830) USGS Quad: BAY ST. LOUIS Longitude: 89° 22.4' W ( -89.37330) T I D A L D A T U M S Tidal datums at WATTS BAYOU, JOURDAN RIVER 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 = 0.556 MEAN HIGH WATER MHW = 0.493 MEAN SEA LEVEL MSL = 0.281 MEAN TIDE LEVEL MTL = 0.274 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 7819 A 1978 0.778 0.285 7819 B 1978 2.526 2.033 7819 D 1978 1.803 1.310 7819 E 1978 1.712 1.219 R 190 1955 4.073 3.580
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 8747819 PUBLICATION DATE: 03/09/2004 Name: WATTS BAYOU, JOURDAN RIVER MS NOAA Chart: 11371 Latitude: 30° 19.7' N ( 30.32830) USGS Quad: BAY ST. LOUIS Longitude: 89° 22.4' W ( -89.37330) 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.