U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8727246 PUBLICATION DATE: 01/06/2004 Name: CHASSAHOWITZKA RIVER FL NOAA Chart: 11409 Latitude: 28° 42.9' N ( 28.71500) USGS Quad: CHASSAHOWITZKA Longitude: 82° 34.6' W ( -82.57670) To reach the tidal bench marks from the First Baptist Church in Chassahowitzka, proceed west on County Road C-480 for 0.8 km (0.5 mi) to South McClung Loop, then west on South McClung Loop for 0.2 km (0.1 mi) to the river. The bench marks are located in the area and along County Road C-480. The tide gage and staff were located on a USGS platform in the river. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 7246 A 1978 DESIGNATION: 872 7246 A TIDAL MONUMENTATION: Tidal Station disk VM#: 7755 AGENCY: National Ocean Survey (NOS) IDB PID#: AL7704 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 28° 42.8' N ( 28.71330) LONGITUDE: 82° 34.5' W ( -82.57500) The primary bench mark is a disk located 0.8 km (0.5 mi) west of the First Baptist Church, 111 m (365 ft) north of bench mark 7246 C 1978, 19 m (61 ft) NW of the centerline of County Road C-480, 14.97 m (49.1 ft) SSW of a buff-colored cinder block house, and 1.04 m (3.4 ft) east of a powerline pole with a witness sign attached. The bench mark is set 5 cm (0.2 ft) above ground level, crimped to the top of a stainless steel rod driven 14.6 m (48 ft) to refusal, and encased in PVC pipe with a concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8727246 PUBLICATION DATE: 01/06/2004 Name: CHASSAHOWITZKA RIVER FL NOAA Chart: 11409 Latitude: 28° 42.9' N ( 28.71500) USGS Quad: CHASSAHOWITZKA Longitude: 82° 34.6' W ( -82.57670) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7246 B 1978 DESIGNATION: 872 7246 B TIDAL MONUMENTATION: Tidal Station disk VM#: 7756 AGENCY: National Ocean Survey (NOS) IDB PID#: AL7706 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 28° 42.8' N ( 28.71330) LONGITUDE: 82° 34.6' W ( -82.57670) The bench mark is a disk set in the top of a concrete monument, 26.61 m (87.3 ft) ESE of the SE corner of a board and batten house, 15.24 m (50.0 ft) south of the centerline of South McClung Loop, 12.74 m (41.8 ft) east of the center hole for a recreational vehicle dumping station at Lykes Chassahowitzka Campground, 1 m (3 ft) SW of power pole #37 with a witness sign attached, and 0.06 m (0.2 ft) below ground level. BENCH MARK STAMPING: 7246 C 1978 DESIGNATION: 872 7246 C TIDAL MONUMENTATION: Tidal Station disk VM#: 7757 AGENCY: National Ocean Survey (NOS) IDB PID#: AL7705 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 28° 42.8' N ( 28.71330) LONGITUDE: 82° 34.5' W ( -82.57500) The bench mark is a disk located 134 m (440 ft) east of bench mark 7246 B 1978, 19.23 m (63.1 ft) NNE of the NE corner of a green stucco house, 7.35 m (24.1 ft) west of the centerline of a paved road leading to Chassahowitzka Village, 5.09 m (16.7 ft) south of the centerline of South McClung Loop, 0.82 m (2.7 ft) WNW of a witness post, and 0.58 m (1.9 ft) SW of a powerline pole. The bench mark is crimped to the top of a stainless steel rod driven 9.8 m (32 ft) to refusal, and encased in a PVC pipe with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8727246 PUBLICATION DATE: 01/06/2004 Name: CHASSAHOWITZKA RIVER FL NOAA Chart: 11409 Latitude: 28° 42.9' N ( 28.71500) USGS Quad: CHASSAHOWITZKA Longitude: 82° 34.6' W ( -82.57670) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7246 D 1978 DESIGNATION: 872 7246 D TIDAL MONUMENTATION: Tidal Station disk VM#: 7758 AGENCY: National Ocean Survey (NOS) IDB PID#: AL7703 SETTING CLASSIFICATION: Concrete monument OPUS PID#: AL7703 LATITUDE: 28° 42.8' N ( 28.71330) LONGITUDE: 82° 34.4' W ( -82.57330) The bench mark is a disk set in the top of a concrete monument, 147 m (483 ft) east of bench mark 7246 A 1978, 13.47 m (44.2 ft) north of the centerline of County Road C-480, 11.46 m (37.6 ft) east of the SE corner of the Chassahowitzka Lodge, 0.85 m (2.8 ft) west of a telephone booth, 0.82 m (2.7 ft) south of a metal witness post, and 0.06 m (0.2 ft) below ground level. NOTE: Mark not found in 1994 by US Power Squadron. BENCH MARK STAMPING: 7246 E E 1978 DESIGNATION: 872 7246 E TIDAL MONUMENTATION: Tidal Station disk VM#: 7759 AGENCY: National Ocean Survey (NOS) IDB PID#: AL7702 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 28° 42.9' N ( 28.71500) LONGITUDE: 82° 34.1' W ( -82.56830) The bench mark is a disk set in the top of a concrete monument, 0.6 km (0.4 mi) east of bench mark 7246 D 1978, 10.82 m (35.5 ft) north of the centerline of County Road C-480, 10 m (32 ft) west of the centerline of Riviera Drive, 8.81 m (28.9 ft) SE of the SE corner of the First Baptist Church, 0.85 m (2.8 ft) north of a powerline pole with a witness sign attached.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8727246 PUBLICATION DATE: 01/06/2004 Name: CHASSAHOWITZKA RIVER FL NOAA Chart: 11409 Latitude: 28° 42.9' N ( 28.71500) USGS Quad: CHASSAHOWITZKA Longitude: 82° 34.6' W ( -82.57670) T I D A L D A T U M S Tidal datums at CHASSAHOWITZKA RIVER based on: LENGTH OF SERIES: 5 MONTHS TIME PERIOD: June 1978 - October 1978 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8727520 CEDAR KEY, GULF OF MEXICO Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.177 MEAN HIGH WATER MHW = 0.143 MEAN TIDE LEVEL MTL = 0.087 MEAN SEA LEVEL MSL = 0.080 MEAN LOW WATER MLW = 0.031 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum NAVD88 = -0.088 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 7246 A 1978 2.425 2.282 7246 B 1978 1.606 1.463 7246 C 1978 2.216 2.073 7246 D 1978 2.859 2.716 7246 E E 1978 2.161 2.018
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8727246 PUBLICATION DATE: 01/06/2004 Name: CHASSAHOWITZKA RIVER FL NOAA Chart: 11409 Latitude: 28° 42.9' N ( 28.71500) USGS Quad: CHASSAHOWITZKA Longitude: 82° 34.6' W ( -82.57670) 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.