U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8761927 PUBLICATION DATE: 10/21/2020 Name: USCG NEW CANAL STA., LAKE PONTCHARTRAIN LA NOAA Chart: 11369 Latitude: 30° 1.6' N ( 30.02722) USGS Quad: SPANISH FORT Longitude: 90° 6.8' W ( -90.11333) To reach the station from the junction of Interstate Highway 10 and Causeway Boulevard, go north for 0.55 km (0.35 mi) on Causeway Boulevard to Veterans Memorial Highway. Turn right and go east for 3.89 km (2.40 mi) on Veterans Memorial Boulevard to Ponchatrain Boulevard. Turn left and go north for 1.85 km (1.15 mi) on Ponchatrain Boulevard to Robert E Lee Boulevard. Countinue straight ahead and go north for 0.72 km (0.45 mi) on Robert E. Lee Boulevard to the New Canal Lighthouse Museum on the left at the east end of a curve in the road. Turn left onto a narrow lane for 30 m (98.4 ft) to the station on the right. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: ALCO 1931 DESIGNATION: ALCO MONUMENTATION: Tidal Station disk VM#: 832 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Sea wall OPUS PID#: BJ1342 LATITUDE: 30° 1.6' N ( 30.02694) LONGITUDE: 90° 6.8' W ( -90.11278) The primary bench mark is a disk set in the top of the sea wall near the Coast Guard Station, 35.0 m (114.8 ft) east of the west end of the sea wall, 34.0 m (111.5 ft) NW of the center line of Lakeshore Drive, and 21.0 m (68.9 ft) east of a steel fence corner post on top of the sea wall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8761927 PUBLICATION DATE: 10/21/2020 Name: USCG NEW CANAL STA., LAKE PONTCHARTRAIN LA NOAA Chart: 11369 Latitude: 30° 1.6' N ( 30.02722) USGS Quad: SPANISH FORT Longitude: 90° 6.8' W ( -90.11333) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1927 D 2005 DESIGNATION: 876 1927 D MONUMENTATION: Tidal Station disk VM#: 17995 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Sea wall OPUS PID#: BBFX22 LATITUDE: 30° 1.6' N ( 30.02700) LONGITUDE: 90° 6.7' W ( -90.11203) The bench mark is a disk set in the sea wall along Lake Ponchatrain, due south of the Jetty Point, 36.49 (119.7 ft) north of Lakeshore Drive, 25.00 m (82.02 ft) NE of the most western light pole in the parking area, and 0.17 m (0.56 ft) from the edge of the sea wall. BENCH MARK STAMPING: 1927 E 2005 DESIGNATION: 876 1927 E MONUMENTATION: Tidal Station disk VM#: 17996 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Sea wall OPUS PID#: BBHW28 LATITUDE: 30° 1.6' N ( 30.02731) LONGITUDE: 90° 6.6' W ( -90.11039) The bench mark is a disk set flush in the seawall along Lake Ponchatrain, 27.25 m (89.40 ft) WNW of light pole "HU8," 24.74 m (81.17 ft) from Lakeshore Drive and the point of the Jetty bears 320.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8761927 PUBLICATION DATE: 10/21/2020 Name: USCG NEW CANAL STA., LAKE PONTCHARTRAIN LA NOAA Chart: 11369 Latitude: 30° 1.6' N ( 30.02722) USGS Quad: SPANISH FORT Longitude: 90° 6.8' W ( -90.11333) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1927 G 2006 DESIGNATION: 876 1927 G MONUMENTATION: Tidal Station disk VM#: 18271 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Sea wall OPUS PID#: BBFX24 LATITUDE: 30° 1.6' N ( 30.02714) LONGITUDE: 90° 6.7' W ( -90.11117) The bench mark is a disk set flush along the seawall located 143.26 m (470.01 ft) north of the centerline of Lakeshore Drive, 83.52 m (274.02 ft) east of bench mark 876 1927 D, 19.51 m (64.01 ft) NW of a slighty more distant lightpole with no number, and 11.89 m (39.01 ft) NNE of a nearby lightpole with no number. BENCH MARK STAMPING: 1927 H 2006 DESIGNATION: 876 1927 H MONUMENTATION: Flange-encased Rod VM#: 18272 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID: LATITUDE: 30° 1.6' N ( 30.02703) LONGITUDE: 90° 6.6' W ( -90.11011) The bench mark is a flange-encased rod located 101.19 m (331.99 ft) SE of benchmark 876 1927 G, 17.37 m (56.99 ft) WSW of a nearby light pole, 12.19 m (39.99 ft) south of centerline of Lakeshore Drive, 9.45 m (31.0 ft) NW of the centerline of the main entrance to Shelter No. 1, and 1.52 m (4.99 ft) south of a light pole and witness post. The datum point is stainless steel rod driven 27.4 m (89.9 ft) to refusal in a sleeve extending to a depth of 0.91 m (2.99 ft) and encased in a 5 inch PVC pipe and concrete kickblock. Note-sleeve depth does not meet the specifications for a class A rod mark.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8761927 PUBLICATION DATE: 10/21/2020 Name: USCG NEW CANAL STA., LAKE PONTCHARTRAIN LA NOAA Chart: 11369 Latitude: 30° 1.6' N ( 30.02722) USGS Quad: SPANISH FORT Longitude: 90° 6.8' W ( -90.11333) T I D A L D A T U M S Tidal datums at USCG NEW CANAL STA., LAKE PONTCHARTRAIN based on: LENGTH OF SERIES: 9 Years TIME PERIOD: 01/10-12/12, 03/13-02/19 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8761305 SHELL BEACH, LAKE BORGNE Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (08/30/2012) = 1.985 MEAN HIGHER HIGH WATER MHHW = 0.165 MEAN HIGH WATER MHW = 0.165 MEAN SEA LEVEL MSL = 0.084 MEAN TIDE LEVEL MTL = 0.082 North American Vertical Datum NAVD88 = 0.071 MEAN LOWER LOW WATER MLLW = 0.000 MEAN LOW WATER MLW = -0.002 LOWEST OBSERVED WATER LEVEL (12/25/1989) = -0.792 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW ALCO 1931 1.839 1.674 1927 D 2005 1.857 1.692 1927 E 2005 1.878 1.713 1927 G 2006 1.900 1.735 1927 H 2006 1.412 1.247
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8761927 PUBLICATION DATE: 10/21/2020 Name: USCG NEW CANAL STA., LAKE PONTCHARTRAIN LA NOAA Chart: 11369 Latitude: 30° 1.6' N ( 30.02722) USGS Quad: SPANISH FORT Longitude: 90° 6.8' W ( -90.11333) 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.