U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 1 of 6 Station ID: 8760849 PUBLICATION DATE: 05/14/1990 Name: VENICE, GRAND PASS LOUISIANA NOAA Chart: 11361 Latitude: 29ø 15.9' N USGS Quad: VENICE Longitude: 89ø 20.9' W To reach the tidal bench marks from State Highway 23 in Venice, proceed south on State Highway 23 until crossing the Mississippi River Levee, then left on Levee Road to the first shell road on the right (marked by a sign reading Venice Sub-Station Corps of Engineers), go south on the shell road to its end and the sub-station to the left. The bench marks are near the sub-station and north along the shell road. The tide gage and staff were on the wharf between the sub-station office and the U.S. Fish and Wildlife Service office. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 0849 A 1985 MONUMENTATION: Survey Disk VM#: 7119 AGENCY: PID#: AT1390 SETTING CLASSIFICATION: Stainless Steel Rod The bench mark is 315.0 feet (96.0 m) north of Bench Mark PBM DARBON 1959, 102.0 feet (31.1 m) north of the chain link fence corner at the NW corner of the U.S. Fish and Wildlife Service storage area (fence corner is guarded by three yellow pipes), 71.2 feet (21.7 m) SE of a water meter on the west side of the shell road, 45.0 feet (13.7 m) east of a fire hydrant on the west side of the shell road, 2.9 feet (0.9 m) SW of a chain link fence, and 2.2 feet (0.7 m) SW of a witness post. The bench mark is at ground level, crimped to a stainless steel rod driven 64 feet (20 m) to refusal, and encased in a 5-inch PVC pipe and concrete kickblock. BENCH MARK STAMPING: PBM DARBON 1959 MONUMENTATION: Survey Disk VM#: 7118 AGENCY: PID#: AT0076 SETTING CLASSIFICATION: Concrete Monument The bench mark is set in the top of a concrete monument near the SW corner of the U.S. Fish and Wildlife Service office, 39.0 feet (11.9 m) WSW of the SW corner of a concrete pad with hoist, 32.4 feet (9.9 m) WNW of a power pole at the NW corner of the sub-station office, 3.2 feet (1.0 m) east of the western- most corner of the chain link fence between the sub-station office and U.S. Fish and Wildlife Service office, and 1.4 feet (0.4 m) above ground level. U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 8760849 PUBLICATION DATE: 05/14/1990 Name: VENICE, GRAND PASS LOUISIANA NOAA Chart: 11361 Latitude: 29ø 15.9' N USGS Quad: VENICE Longitude: 89ø 20.9' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 0849 B 1985 MONUMENTATION: Survey Disk VM#: 7120 AGENCY: PID: SETTING CLASSIFICATION: Stainless Steel Rod The bench mark is 252.6 feet (77.0 m) NW of Bench Mark 0849 A 1985, 121.0 feet (36.9 m) ESE of a fire hydrant near a wooden walkway to an old house, 9 feet (3 m) SSW of the SW corner of the Freeport Sulphur Company parking area, 3.8 feet (1.2 m) SSE of a power pole near the SW corner of the chain link fence around the Freeport Sulphur Company property, and 1.3 feet (0.4 m) SW of a witness post. The bench mark is 0.2 foot (0.1 m) below ground level, crimped to a stainless steel rod driven 60 feet (18 m) to refusal, and encased in a 5-inch PVC pipe and concrete kickblock. BENCH MARK STAMPING: 0849 C 1985 MONUMENTATION: Survey Disk VM#: 7121 AGENCY: PID: SETTING CLASSIFICATION: Stainless Steel Rod The bench mark is 253.0 feet (77.1 m) NNW of Bench Mark 0849 B 1985, 83.3 feet (25.4 m) NNW of a power pole on the east side of the shell road, 65.6 feet (20.0 m) north of a fire hydrant near the walkway to the old wood frame house, 53.8 feet (16.4 m) NNE of a power pole on the west side of the shell road (power pole is at the corner of a driveway near a leaning wooden pile), 37.2 feet (11.3 m) ESE of a power pole on the east side of the shell road, 2.1 feet (0.6 m) SW of a chain link fence, and 1.5 feet (0.4 m) SW of a witness post. The bench mark is 0.6 foot (0.2 m) below ground level, crimped to a stainless steel rod driven 60 feet (18 m) to refusal, and encased in a 5-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: 8760849 PUBLICATION DATE: 05/14/1990 Name: VENICE, GRAND PASS LOUISIANA NOAA Chart: 11361 Latitude: 29ø 15.9' N USGS Quad: VENICE Longitude: 89ø 20.9' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 0849 D 1985 MONUMENTATION: Survey Disk VM#: 7122 AGENCY: PID: SETTING CLASSIFICATION: Stainless Steel Rod The bench mark is 344.3 feet (104.9 m) WNW of Bench Mark 0849 C 1985, 80.6 feet (24.6 m) NE of a wooden sign post marking the boundary of a wildlife area (sign post is at the SW corner of the intersection of the shell road with Levee Road), 58.6 feet (17.9 m) ESE of the centerline of Levee Road, 41.3 feet (12.6 m) SSE of the west corner of a chain link fence on the SE corner of the intersection of the shell road and Levee Road, 20 feet (6 m) WSW of the base of a brace pole for a power pole at the SW corner of the intersection of the shell access road and Levee Road, and 1.6 feet (0.5 m) SW of a witness post. The bench mark is 0.7 foot (0.2 m) below ground level, crimped to a stainless steel rod driven 56 feet (17 m) to refusal, and encased in a 5-inch PVC pipe and concrete kickblock. BENCH MARK STAMPING: 0849 E 1987 MONUMENTATION: Survey Disk VM#: 7123 AGENCY: PID: SETTING CLASSIFICATION: Stainless Steel Rod The bench mark is 210.0 feet (64.0 m) WSW of Bench Mark 0849 D 1985, 140.0 feet (42.7 m) NE of the first utility pole WSW of a timber dock at the NW end of a slip extending from Grand Pass, l37.0 feet (4l.8 m) east of a curve warning and speed limit sign east of State Highway 23, 121.0 feet (36.9 m) north of the NW corner of the previously described timber dock, 33.5 feet (10.2 m) NW of the NW edge of River Road, and 2.0 feet (0.6 m) from a witness post. The bench mark is at ground level, crimped to a stainless steel rod driven 64 feet (20 m) to refusal, and encased in a 5-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: 8760849 PUBLICATION DATE: 05/14/1990 Name: VENICE, GRAND PASS LOUISIANA NOAA Chart: 11361 Latitude: 29ø 15.9' N USGS Quad: VENICE Longitude: 89ø 20.9' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 0849 F 1987 MONUMENTATION: Survey Disk VM#: 7124 AGENCY: PID: SETTING CLASSIFICATION: Stainless Steel Rod The bench mark is 118.5 feet (36.1 m) NE of the first utility pole WSW of the timber dock at the NW end of a slip extending from Grand Pass, 114.0 feet (34.8 m) east of a curve warning and speed limit sign east of State Highway 23, 30.0 feet (9.l m) SW of Bench Mark 0849 E 1987, and 2.0 feet (0.6 m) from a witness post. The bench mark is at ground level, crimped to a stainless steel rod driven 16 feet (5 m), and encased in a 5-inch PVC pipe and concrete kickblock. U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 8760849 PUBLICATION DATE: 05/14/1990 Name: VENICE, GRAND PASS LOUISIANA NOAA Chart: 11361 Latitude: 29ø 15.9' N USGS Quad: VENICE Longitude: 89ø 20.9' W T I D A L D A T U M S Tidal datums at VENICE, GRAND PASS based on: LENGTH OF SERIES: 10 MONTHS TIME PERIOD: JANUARY-OCTOBER 1986 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 8767437 BAY WAVELAND, MS Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET: HIGHEST OBSERVED WATER LEVEL (10/27/1985) = 3.54 MEAN HIGHER HIGH WATER (MHHW) = 0.87 MEAN HIGH WATER (MHW) = 0.86 MEAN TIDE LEVEL (MTL) = 0.44 MEAN LOW WATER (MLW) = 0.02 MEAN LOWER LOW WATER (MLLW) = 0.00 LOWEST OBSERVED WATER LEVEL (10/07/1985) = -0.95 * NATIONAL GEODETIC VERTICAL DATUM-1929 (NGVD) = -1.33 * NGVD reference based on elevations published in Quad HGZ L248, 1984, and NOS leveling of 1986. Bench Mark Elevation Information In FEET above: Stamping or Designation MLLW MHW 0849 A 1985 2.33 1.47 PBM DARBON 1959 3.50 2.64 0849 B 1985 1.26 0.40 0849 C 1985 1.93 1.07 0849 D 1985 2.09 1.23 0849 E 1987 3.15 2.29 0849 F 1987 3.03 2.17 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 8760849 PUBLICATION DATE: 05/14/1990 Name: VENICE, GRAND PASS LOUISIANA NOAA Chart: 11361 Latitude: 29ø 15.9' N USGS Quad: VENICE Longitude: 89ø 20.9' W 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 (NAVD 88). NGVD 29 is a fixed datum adopted as a national standard geodetic reference for heights but is now considered superseded. NGVD 29 is sometimes referred to as Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological Survey Topographic Quads. NGVD 29 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 NGVD 29 are available from the National Geodetic Survey (NGS) data base via the World Wide Web at National Geodetic Survey. NAVD 88 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. NAVD 88 replaces NGVD 29 as the national standard geodetic reference for heights. Bench mark elevations relative to NAVD 88 are available from NGS through the World Wide Web at National Geodetic Survey. NGVD 29 and NAVD 88 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 NAVD 88 elevation is shown on the Elevations of Tidal Datums Table Referred to MLLW only when two or more of the bench marks listed have NAVD 88 elevations. The NAVD 88 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, NAVD 88 bench mark elevations computed indirectly from the tidal datums elevation table may differ slightly from NAVD 88 elevations listed for each bench mark in the NGS database.