U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 4 PUBLICATION DATE: 06/21/1984 Station ID: 8729974 SUPERCEDED DATE: 04/21/2003 Name: PERDIDO KEY, OLD RIVER FLORIDA NOAA Chart: 11382 Latitude: 30° 18.2' N USGS Quad: PERDIDO BAY Longitude: 87° 26.7' W To reach the tidal bench marks from the south end of the SR292 bridge over Old River, proceed SW on Gulf Beach Highway 2.3 miles (3.7 km) to a black top road leading NW, then on the black top road continue 0.4 miles (0.6 km) to a private residence on the north side of the road. The bench marks are located along the blacktop road, and the tide gage and staff were located on a dock behind a private residence (Kaufman). T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 9974 A 1977 MONUMENTATION: Survey Disk VM#: 10332 AGENCY: PID#: BG3646 SETTING CLASSIFICATION: Copper-Coated Steel Rod The bench mark is in front of the Kaufman residence, 67.5 feet (20.6 m) east of Bench Mark 9974 E 1977, 28.2 feet (8.6 m) NW of the centerline of a blacktop road, and 7.0 feet (2.1 m) NE of a power pole. The bench mark is 0.2 foot (0.1 m) below ground level, crimped to a copper-coated steel rod driven to refusal and encased in a 4-inch PVC pipe and concrete kickblock. BENCH MARK STAMPING: 9974 B 1977 MONUMENTATION: Survey Disk VM#: 10333 AGENCY: PID#: BG3644 SETTING CLASSIFICATION: Copper-Coated Steel Rod The bench mark is 385 feet (117 m) SW of Bench Mark 9974 A 1977, 62 feet (19 m) SW of the center of a drainage ditch, 25 feet (8 m) NE of a power pole, 23 feet (7 m) NW of the centerline of the blacktop road. The bench mark is 0.5 foot (0.2 m) below ground level, crimped to a copper-coated steel rod driven to refusal and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 4 PUBLICATION DATE: 06/21/1984 Station ID: 8729974 SUPERCEDED DATE: 04/21/2003 Name: PERDIDO KEY, OLD RIVER FLORIDA NOAA Chart: 11382 Latitude: 30° 18.2' N USGS Quad: PERDIDO BAY Longitude: 87° 26.7' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 9974 C 1977 MONUMENTATION: Survey Disk VM#: 10334 AGENCY: PID#: BG3643 SETTING CLASSIFICATION: Copper-Coated Steel Rod The bench mark is 300 feet (91 m) SW of Bench Mark 9974 B 1977, 86.5 feet (26.3 m) NE of the NE corner of house #1018, and 18.4 feet (5.6 m) NW of the centerline of a blacktop road. The bench mark is 0.3 foot (0.1 m) below ground level, crimped to a copper-coated steel rod driven to refusal and encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: 9974 D 1977 MONUMENTATION: Survey Disk VM#: 10335 AGENCY: PID#: BG3642 SETTING CLASSIFICATION: Copper-Coated Steel Rod The bench mark is 330 feet (101 m) SW of Bench Mark 9974 C 1977, 161.5 feet (49.2 m) SE of the SE corner of house#1019, 59 feet (18 m) SE of power pole 0913, and 26 feet (8 m) SE of the centerline of the blacktop road. The bench mark is 0.1 foot (0.03 m) below ground level, crimped to a copper-coated steel rod driven to refusal and encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: 9974 E 1977 MONUMENTATION: Survey Disk VM#: 10336 AGENCY: PID#: BG3645 SETTING CLASSIFICATION: Concrete Foundation The bench mark is set flush in the NW corner of a concrete pump slab, 75.4 feet (23.0 m) SE of the NE corner of house #1017, 67.5 feet (20.6 m) west of Bench Mark 9974 A 1977 and 33 feet (10 m) NE of the centerline of the driveway for house #1017.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 4 PUBLICATION DATE: 06/21/1984 Station ID: 8729974 SUPERCEDED DATE: 04/21/2003 Name: PERDIDO KEY, OLD RIVER FLORIDA NOAA Chart: 11382 Latitude: 30° 18.2' N USGS Quad: PERDIDO BAY Longitude: 87° 26.7' W T I D A L D A T U M S Tidal datums at PERDIDO KEY, OLD RIVER based on: LENGTH OF SERIES: 2 MONTHS TIME PERIOD: MARCH-APRIL 1977 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 8729840 PENSACOLA Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET: HIGHEST OBSERVED WATER LEVEL (03/28/1977) = 1.75 MEAN HIGHER HIGH WATER MHHW = 0.64 MEAN HIGH WATER MHW = 0.60 MEAN TIDE LEVEL MTL = 0.30 MEAN LOW WATER MLW = 0.01 MEAN LOWER LOW WATER MLLW = 0.00 LOWEST OBSERVED WATER LEVEL (01/20/1977) = -1.30 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In FEET above: Stamping or Designation MLLW MHW 9974 A 1977 3.76 3.16 9974 B 1977 2.82 2.22 9974 C 1977 5.40 4.80 9974 D 1977 3.77 3.17 9974 E 1977 4.98 4.38
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 4 PUBLICATION DATE: 06/21/1984 Station ID: 8729974 SUPERCEDED DATE: 04/21/2003 Name: PERDIDO KEY, OLD RIVER FLORIDA NOAA Chart: 11382 Latitude: 30° 18.2' N USGS Quad: PERDIDO BAY Longitude: 87° 26.7' 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 (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 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.