U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8662670 PUBLICATION DATE: 03/09/2004 Name: PLEASANT HILL LANDING, SANTEE RIVER SC NOAA Chart: Latitude: 33° 14.7' N ( 33.24500) USGS Quad: HONEY HILL Longitude: 79° 31.3' W ( -79.52170) To reach the tidal bench marks from U.S. Highway 17 at McClellanville, proceed north on U.S. Highway 17 for 9.5 km (5.9 mi) to State Road S-10-857, then turn left and proceed west on State Road S-10-857 for 5.1 km (3.2 mi) to the end of the paved road, then continue west on the dirt road for 2.4 km (1.5 mi), then turn left and go 0.2 km (0.1 mi) to the Elmwood Ranger Station entrance, turn right to the station and continue past the station for 0.6 km (0.4 mi) to Echaw Road (Forest Route 204), then turn right onto Echaw Road and go 9.3 km (5.8 mi) to the North Hampton Hunt Unit gate, go through the gate, then turn right and proceed west on a clay bed road for 1.4 km (0.9 mi) to a fork, bear right and proceed north on Forest Route 204 F for 0.3 km (0.2 mi) to the South Carolina Gas and Electric right-of-way with a pumping station to the left, and continue past the clearing for 1.1 km (0.7 mi) to Pleasant Hill Landing. NOTE: Access to this site after a moderate rain usually requires a 4-wheel drive vehicle. The tidal bench marks are along the road leading to the landing. The tide gage and staff were on a pier just west of the boat ramp. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 2670 A 1976 DESIGNATION: 866 2670 A MONUMENTATION: Tidal Station disk VM#: 3938 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Copper clad steel rod OPUS PID: LATITUDE: 33° 14.7' N ( 33.24500) LONGITUDE: 79° 31.1' W ( -79.51830) The primary bench mark is a disk located near the pier just west of the boat ramp, 18.59 m (61.0 ft) WNW of the centerline of a dirt path leading to the pier, 10.85 m (35.6 ft) west of a 0.61 m (2.0 ft) diameter hickory tree, 9.51 m (31.2 ft) NE of a 0.3 m (1 ft) diameter pine tree, 5 m (16 ft) SSW of the edge of the south bank of the river, and 4.48 m (14.7 ft) SW of a 0.46 m (1.5 ft) diameter gum tree. The bench mark is crimped to the top of a copper-clad steel rod driven 12.2 m (40 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8662670 PUBLICATION DATE: 03/09/2004 Name: PLEASANT HILL LANDING, SANTEE RIVER SC NOAA Chart: Latitude: 33° 14.7' N ( 33.24500) USGS Quad: HONEY HILL Longitude: 79° 31.3' W ( -79.52170) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 2670 G 1982 DESIGNATION: 866 2670 G MONUMENTATION: Tidal Station disk VM#: 3939 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 33° 14.7' N ( 33.24500) LONGITUDE: 79° 31.1' W ( -79.51830) The bench mark is a disk set in a concrete monument along the west side of the road leading to Pleasant Hill Landing, 74 m (244 ft) north of 2670 H 1982, 11.0 m (36.0 ft) WNW of the center of the rock paved parking area, 8.99 m (29.5 ft) east of a metal double trash receptacle, 5.49 m (18.0 ft) north of a 1.5-foot (0.5 m) diameter pine tree, 0.76 m (2.5 ft) WNW of the center of a wooden guard rail, and 6 cm (0.2 ft) above ground level. BENCH MARK STAMPING: 2670 H 1982 DESIGNATION: 866 2670 H MONUMENTATION: Tidal Station disk VM#: 3940 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 33° 14.7' N ( 33.24500) LONGITUDE: 79° 31.1' W ( -79.51830) The bench mark is a disk set in a concrete monument along the west side of the road leading to Pleasant Hill Landing, 18.47 m (60.6 ft) SSE of a 0.40 m (1.3 ft) diameter metal drain pipe, 8.38 m (27.5 ft) WSW of the centerline of the dirt road, 1.80 m (5.9 ft) SSE of a 0.37 m (1.2 ft) diameter pine tree, 0.40 m (1.3 ft) ENE of a metal witness post with sign, and 9 cm (0.3 ft) below ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8662670 PUBLICATION DATE: 03/09/2004 Name: PLEASANT HILL LANDING, SANTEE RIVER SC NOAA Chart: Latitude: 33° 14.7' N ( 33.24500) USGS Quad: HONEY HILL Longitude: 79° 31.3' W ( -79.52170) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 2670 J 1982 DESIGNATION: 866 2670 J MONUMENTATION: Tidal Station disk VM#: 3941 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 33° 14.7' N ( 33.24500) LONGITUDE: 79° 31.1' W ( -79.51830) The bench mark is a disk set in a concrete monument along the west side of the road leading to Pleasant Hill Landing, 77.57 m (254.5 ft) north of 2670 K 1982, 6.92 m (22.7 ft) west of the centerline of the dirt road, 6.77 m (22.2 ft) south of the 0.37 m (1.2 ft) diameter gum tree, 0.88 m (2.9 ft) NNW of a metal witness post with sign, and 6 cm (0.2 ft) above ground level. BENCH MARK STAMPING: 2670 K 1982 DESIGNATION: 866 2670 K MONUMENTATION: Tidal Station disk VM#: 3942 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 33° 14.7' N ( 33.24500) LONGITUDE: 79° 31.1' W ( -79.51830) The bench mark is a disk set in a concrete monument along the east side of the road leading to Pleasant Hill Landing, 7.83 m (25.7 ft) ESE of the centerline of the dirt road, 1.83 m (6.0 ft) SW of a 0.61 m (2.0 ft) diameter pine tree, 1.71 m (5.6 ft) NNE of a 0.37 m (1.2 ft) diameter pine tree, 0.40 m (1.3 ft) west of a metal witness post with sign, and level with the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8662670 PUBLICATION DATE: 03/09/2004 Name: PLEASANT HILL LANDING, SANTEE RIVER SC NOAA Chart: Latitude: 33° 14.7' N ( 33.24500) USGS Quad: HONEY HILL Longitude: 79° 31.3' W ( -79.52170) T I D A L D A T U M S Tidal datums at PLEASANT HILL LANDING, SANTEE RIVER based on: LENGTH OF SERIES: 3 MONTHS TIME PERIOD: May 1977 - July 1977 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8662799 US HIGHWAY 17, SOUTH SANTEE RIVER Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.805 MEAN HIGH WATER MHW = 0.745 MEAN TIDE LEVEL MTL = 0.394 MEAN SEA LEVEL MSL = 0.390 MEAN LOW WATER MLW = 0.043 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 2670 A 1976 6.697 5.952 2670 G 1982 4.845 4.100 2670 H 1982 3.791 3.046 2670 J 1982 3.753 3.008 2670 K 1982 5.257 4.512
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8662670 PUBLICATION DATE: 03/09/2004 Name: PLEASANT HILL LANDING, SANTEE RIVER SC NOAA Chart: Latitude: 33° 14.7' N ( 33.24500) USGS Quad: HONEY HILL Longitude: 79° 31.3' W ( -79.52170) 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.