U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8666359 PUBLICATION DATE: 05/06/2003 Name: BLUFF PLANTATION, COMBAHEE RIVER SC NOAA Chart: 11519 Latitude: 32° 41.0' N ( 32.68330) USGS Quad: GREEN POND Longitude: 80° 44.3' W ( -80.73830) To reach the tidal bench marks from the junction of US Highways 17 and 17 A (21 N), proceed north on US Highway 17A for 18.3 km (11.4 mi) to County Road S-15-66, then turn right and go east on County Road S-15-66 for 9.0 km (5.6 mi) to Bluff Plantation, then turn right and go 0.3 km (0.2 mi) to the turn around circle. The bench marks are along the east driveway of Bluff Plantation. The gauge and staff were on a small wooden pier on the Combahee River at the mouth of the canal. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: B.P. NO. 2 1975 DESIGNATION: 866 6359 TIDAL BP 2 MONUMENTATION: Tidal Station disk VM#: 10587 AGENCY: National Ocean Survey (NOS) IDB PID#: CK2948 SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 32° 41.1' N ( 32.68500) LONGITUDE: 80° 44.0' W ( -80.73330) The primary bench mark is a disk located in the vicinity of the turn around circle on the Bluff Plantation, 61.57 m (202.0 ft) WSW of the NW post of the overhang on the horse stables, 29.81 m (97.8 ft) NNE of a 1.22 m (4.0 ft) diameter magnolia tree, 24.69 m (81.0 ft) north of a 0.61 m (2.0 ft) diameter cedar tree, 13.87 m (45.5 ft) south of the centerline of the asphalt road leading from turning circle to the stables, and 2.44 m (8.0 ft) west of a 0.61 m (2.0 ft) diameter pine tree. The bench mark is set 3 cm (0.1 ft) below ground level, crimped to a copper-clad steel rod driven 12.2 m (40 ft) to refusal, and encased in a 4 inch PVC pipe and concrete kicblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8666359 PUBLICATION DATE: 05/06/2003 Name: BLUFF PLANTATION, COMBAHEE RIVER SC NOAA Chart: 11519 Latitude: 32° 41.0' N ( 32.68330) USGS Quad: GREEN POND Longitude: 80° 44.3' W ( -80.73830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: B.P. NO. 3 1975 DESIGNATION: 866 6359 TIDAL BP 3 MONUMENTATION: Tidal Station disk VM#: 10588 AGENCY: National Ocean Survey (NOS) IDB PID#: CK2947 SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 32° 41.2' N ( 32.68670) LONGITUDE: 80° 44.0' W ( -80.73330) The bench mark is a disk located along the east side of the east drive of Bluff Plantation, 146.58 m (480.9 ft) NE of bench mark B.P. NO. 2 1975, 46.33 m (152.0 ft) NW of the white fence around horse pasture, 15.39 m (50.5 ft) south of the south edge of the drainage ditch, 3.72 m (12.2 ft) north of the 10th live oak tree along east side of east drive and 3.66 m (12.0 ft) east of the centerline of the east drive. The bench mark is set 9 cm (0.3 ft) below ground level, crimped to a copper-clad steel rod driven 9.8 m (32 ft) to refusal, and encased in 4 inch PVC pipe and concrete kickblock. BENCH MARK STAMPING: B.P. NO. 4 1975 DESIGNATION: 866 6359 TIDAL BP 4 MONUMENTATION: Tidal Station disk VM#: 10589 AGENCY: National Ocean Survey (NOS) IDB PID#: CK2946 SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 32° 41.2' N ( 32.68670) LONGITUDE: 80° 44.0' W ( -80.73330) The bench mark is a disk located near the east edge of a small pond on the west side of the east drive of the Bluff Plantation, 23.68 m (77.7 ft) SW of a 1.52 m (5.0 ft) diameter live oak tree (the 4th tree from entrance on east side of drive), 9.14 m (30.0 ft) west of the centerline of the east drive, and 3.96 m (13.0 ft) east of a 0.91 m (3.0 ft) diameter live oak tree on the east side of pond. The bench mark is set 6 cm (0.2 ft) below ground level, crimped to a copper-clad steel rod driven 14.6 m (48 ft) to refusal, and encased in 4- inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8666359 PUBLICATION DATE: 05/06/2003 Name: BLUFF PLANTATION, COMBAHEE RIVER SC NOAA Chart: 11519 Latitude: 32° 41.0' N ( 32.68330) USGS Quad: GREEN POND Longitude: 80° 44.3' W ( -80.73830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 19 FEET DATUM 1917 DESIGNATION: 19 MONUMENTATION: Survey disk VM#: 10590 AGENCY: US Geological Survey (USGS) IDB PID#: CK2945 SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 32° 41.3' N ( 32.68830) LONGITUDE: 80° 44.0' W ( -80.73330) The bench mark is a disk located on the NW side of the east drive at the entrance to the Bluff Plantation, 18 m (59 ft) west of the underground phone cable box 13-32-14, 10.36 m (34.0 ft) south of the centerline of County Road S-15-66, 5.46 m (17.9 ft) west of the centerline of the east entrance, and 1.04 m (3.4 ft) north of the north face of the brick wall at the east entrance. The bench mark is set 0.37 m (1.2 ft) above ground level, bolted to the top of a 3 inch diameter steel pipe, surrounded by concrete. BENCH MARK STAMPING: 6359 F 1981 DESIGNATION: 866 6359 F TIDAL MONUMENTATION: Tidal Station disk VM#: 10591 AGENCY: National Ocean Survey (NOS) IDB PID#: CK2949 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 32° 41.0' N ( 32.68330) LONGITUDE: 80° 44.0' W ( -80.73330) The bench mark is a disk set flush in the top of a concrete monument near Nathaniel Heyward's tomb on the SE side of the Bluff Plantation, 26.61 m (87.3 ft) SSW of the SW corner of the tennis courts, 22.13 m (72.6 ft) NNE of the approximate edge of the river bank, 9.97 m (32.7 ft) east of a cedar tree, 5.91 m (19.4 ft) west of a 0.46 m (1.5 ft) diameter oak tree, and 0.58 m (1.9 ft) SSW of the NE corner of the brick wall around the Nathaniel Heywards grave site.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8666359 PUBLICATION DATE: 05/06/2003 Name: BLUFF PLANTATION, COMBAHEE RIVER SC NOAA Chart: 11519 Latitude: 32° 41.0' N ( 32.68330) USGS Quad: GREEN POND Longitude: 80° 44.3' W ( -80.73830) T I D A L D A T U M S Tidal datums at BLUFF PLANTATION, COMBAHEE RIVER based on: LENGTH OF SERIES: 3 YEARS TIME PERIOD: January 1981 - December 1983 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8665530 CHARLESTON, COOPER RIVER ENTRANCE Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (02/28/1983) = 1.509 MEAN HIGHER HIGH WATER MHHW = 1.134 MEAN HIGH WATER MHW = 1.080 MEAN SEA LEVEL MSL = 0.675 MEAN TIDE LEVEL MTL = 0.593 North American Vertical Datum NAVD88 = 0.360 MEAN LOW WATER MLW = 0.106 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (12/16/1981) = -0.801 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW B.P. NO. 2 1975 5.433 4.353 B.P. NO. 3 1975 4.163 3.083 B.P. NO. 4 1975 4.202 3.122 19 FEET DATUM 1917 5.735 4.655 6359 F 1981 5.598 4.518
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8666359 PUBLICATION DATE: 05/06/2003 Name: BLUFF PLANTATION, COMBAHEE RIVER SC NOAA Chart: 11519 Latitude: 32° 41.0' N ( 32.68330) USGS Quad: GREEN POND Longitude: 80° 44.3' W ( -80.73830) 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.