U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8729974 PUBLICATION DATE: 06/28/2004 Name: PERDIDO KEY, OLD RIVER FL NOAA Chart: 11382 Latitude: 30° 18.0' N ( 30.30000) USGS Quad: PERDIDO BAY Longitude: 87° 26.9' W ( -87.44830) To reach the tidal bench marks from the south end of the State Road 292 bridge over Old River at Perdido Key, proceed SW on State Road 292 for 3.7 km (2.3 mi) to River Road, then turn right and proceed NE on the paved road for 0.6 km (0.4 mi) to house # 1017 (R.J. Bell residence). The bench marks are along River Road. The tide gage and staff were located on a dock at the Bell residence. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 9974 A 1977 DESIGNATION: 872 9974 A TIDAL MONUMENTATION: Tidal Station disk VM#: 10332 AGENCY: National Ocean Survey (NOS) IDB PID#: BG3646 SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 30° 18.0' N ( 30.30000) LONGITUDE: 87° 26.8' W ( -87.44670) The primary bench mark is a disk located near the east corner of the Bell property, 20.57 m (67.5 ft) east of bench mark 9974 E 1977, 8.60 m (28.2 ft) NW of the centerline of the paved road, and 2.13 m (7.0 ft) NE of a powerline pole, and 0.15 m (0.5 ft) SE of a witness post. The bench mark is set 6 cm (0.2 ft) below ground level, crimped to the top of a copper-clad steel rod driven an unspecified depth 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 5 Station ID: 8729974 PUBLICATION DATE: 06/28/2004 Name: PERDIDO KEY, OLD RIVER FL NOAA Chart: 11382 Latitude: 30° 18.0' N ( 30.30000) USGS Quad: PERDIDO BAY Longitude: 87° 26.9' W ( -87.44830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 9974 B 1977 DESIGNATION: 872 9974 B TIDAL MONUMENTATION: Tidal Station disk VM#: 10333 AGENCY: National Ocean Survey (NOS) IDB PID#: BG3644 SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 30° 17.9' N ( 30.29830) LONGITUDE: 87° 26.9' W ( -87.44830) The bench mark is a disk located 117 m (385 ft) SW of bench mark 9974 A 1977, 19 m (62 ft) SW of the center of a drainage ditch, 8 m (25 ft) NE of a powerline pole, 7 m (23 ft) NW of the centerline of the paved road, and 0.15 m (0.5 ft) SE of a witness post. The bench mark is set 0.15 m (0.5 ft) below ground level, crimped to the top of a copper-clad steel rod driven an unspecified depth to refusal, and encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: 9974 C 1977 DESIGNATION: 872 9974 C TIDAL MONUMENTATION: Tidal Station disk VM#: 10334 AGENCY: National Ocean Survey (NOS) IDB PID#: BG3643 SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID#: BG3643 LATITUDE: 30° 17.9' N ( 30.29830) LONGITUDE: 87° 27.0' W ( -87.45000) The bench mark is a disk located 91 m (300 ft) SW of bench mark 9974 B 1977, 26.37 m (86.5 ft) east of the east corner of house # 1018, 5.61 m (18.4 ft) NW of the centerline of the paved road, and 0.15 m (0.5 ft) SE of a witness post. The bench mark is set 9 cm (0.3 ft) below ground level, crimped to the top of a copper-clad steel rod driven an unspecified depth 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 3 of 5 Station ID: 8729974 PUBLICATION DATE: 06/28/2004 Name: PERDIDO KEY, OLD RIVER FL NOAA Chart: 11382 Latitude: 30° 18.0' N ( 30.30000) USGS Quad: PERDIDO BAY Longitude: 87° 26.9' W ( -87.44830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 9974 E 1977 DESIGNATION: 872 9974 E TIDAL MONUMENTATION: Tidal Station disk VM#: 10336 AGENCY: National Ocean Survey (NOS) IDB PID#: BG3645 SETTING CLASSIFICATION: Concrete pump slab OPUS PID: LATITUDE: 30° 18.0' N ( 30.30000) LONGITUDE: 87° 26.8' W ( -87.44670) The bench mark is a disk set in the top of the NW corner of a concrete slab for a water pump, 22.98 m (75.4 ft) SE of the east corner of house # 1017, 20.57 m (67.5 ft) west of bench mark 9974 A 1977 and 10 m (33 ft) NE of the centerline of the driveway to the house.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8729974 PUBLICATION DATE: 06/28/2004 Name: PERDIDO KEY, OLD RIVER FL NOAA Chart: 11382 Latitude: 30° 18.0' N ( 30.30000) USGS Quad: PERDIDO BAY Longitude: 87° 26.9' W ( -87.44830) 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: February 1994 - March 1994 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8729840 PENSACOLA, PENSACOLA BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.247 MEAN HIGH WATER MHW = 0.239 MEAN TIDE LEVEL MTL = 0.117 MEAN SEA LEVEL MSL = 0.115 North American Vertical Datum NAVD88 = 0.008 MEAN LOW WATER MLW = 0.007 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 9974 A 1977 1.120 0.881 9974 B 1977 0.832 0.593 9974 C 1977 1.621 1.382 9974 E 1977 1.491 1.252
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8729974 PUBLICATION DATE: 06/28/2004 Name: PERDIDO KEY, OLD RIVER FL NOAA Chart: 11382 Latitude: 30° 18.0' N ( 30.30000) USGS Quad: PERDIDO BAY Longitude: 87° 26.9' W ( -87.44830) 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.