U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 4 PUBLICATION DATE: 10/22/1984 Station ID: 8725769 SUPERCEDED DATE: 04/21/2003 Name: EL JOBEAN, MYAKKA RIVER FLORIDA NOAA Chart: 11426 Latitude: 26° 57.7' N USGS Quad: EL JOBEAN Longitude: 82° 12.6' W To reach the tidal bench marks, in Sarasota, Florida, proceed to Federal Route 41, go south on Federal Route 41 south 5.0 miles (8.0 km) pass its intersection with State Route 72 to State Road 771 follow this road 10 miles (16.1 km) to the bridge. The bench marks are along bridge. The tide gage and staff were located under railroad bridge at south end of north bridge section. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 5769 A 1977 MONUMENTATION: Survey Disk VM#: 6054 AGENCY: PID#: AG7765 SETTING CLASSIFICATION: Seawall The bench mark is at north end of bridge over the Myakka River, 148.0 feet (45.1 m) north of Bench Mark 5769 B 1977, 42.0 feet (12.8 m) east of centerline of Highway 45, 1.5 feet (0.5 m) south of north end of seawall, and set in top of the seawall. BENCH MARK STAMPING: 5769 B 1977 MONUMENTATION: Survey Disk VM#: 6055 AGENCY: PID#: AG7766 SETTING CLASSIFICATION: Seawall The bench mark is at the north end of the bridge oer the Myakka River, 192.0 feet (58.5 m) north of Bench Mark 5769 C 1977, 148.0 feet (45.1 m) south of Bench Mark 5769 A 1977, 42.0 feet (12.8 m) east of centerline of Highway 771 (alt. 45) and 1.0 foot (0.3 m) west of east edge of seawall, and is set in top of the seawall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 4 PUBLICATION DATE: 10/22/1984 Station ID: 8725769 SUPERCEDED DATE: 04/21/2003 Name: EL JOBEAN, MYAKKA RIVER FLORIDA NOAA Chart: 11426 Latitude: 26° 57.7' N USGS Quad: EL JOBEAN Longitude: 82° 12.6' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5769 C 1977 MONUMENTATION: Survey Disk VM#: 6056 AGENCY: PID#: AG7767 SETTING CLASSIFICATION: Seawall The bench mark is at the north end of the bridge over the Myakka River, 192.0 feet (58.5 m) south of Bench Mark 5769 B 1977, 175.0 feet (53.3 m) NE of S.R.D. Bench Mark, 43.0 feet (13.1 m) east of centerline of Highway 771 (alt. 45), 20.0 feet (6.1 m) east of east curb of Highway 771 (alt. 45) and 1.0 foot (0.3 m) west of east edge of seawall, and is set in top of the seawall. BENCH MARK STAMPING: UNSTAMPED MONUMENTATION: Survey Disk VM#: 6057 AGENCY: PID#: AG7769 SETTING CLASSIFICATION: Concrete Banister The bench mark is set in banister of bridge on west side of north end of bridge over the Myakka River, 175.0 feet (53.3 m) southwest of Bench Mark 5769 C 1977, 19.0 feet (5.8 m) west of centerline of Highway 771 (alt. 45) and 4.0 feet (1.2 m) west of west curb and walkway on bridge. BENCH MARK STAMPING: MYAKKA 1981 MONUMENTATION: Survey Disk VM#: 6058 AGENCY: PID#: AG7768 SETTING CLASSIFICATION: Sidewalk The bench mark is set into sidewalk of bridge on the north side of the east end of the bridge over the Myakka River, 8.5 feet (2.6 m) north of Florida S.R.D. Bench Mark, 4.5 feet (1.4 m) west of street edge of curb and 2.9 feet (0.9 m) east of the Myakka River sign.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 4 PUBLICATION DATE: 10/22/1984 Station ID: 8725769 SUPERCEDED DATE: 04/21/2003 Name: EL JOBEAN, MYAKKA RIVER FLORIDA NOAA Chart: 11426 Latitude: 26° 57.7' N USGS Quad: EL JOBEAN Longitude: 82° 12.6' W T I D A L D A T U M S Tidal datums at EL JOBEAN, MYAKKA RIVER based on: LENGTH OF SERIES: 5 MONTHS TIME PERIOD: AUG. - DEC. 1977 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 8725744 PUNTA GORDA Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET: HIGHEST OBSERVED WATER LEVEL (09/26/1977) = 3.05 MEAN HIGHER HIGH WATER MHHW = 2.05 MEAN HIGH WATER MHW = 1.78 MEAN TIDE LEVEL MTL = 1.11 MEAN LOW WATER MLW = 0.44 MEAN LOWER LOW WATER MLLW = 0.00 LOWEST OBSERVED WATER LEVEL (11/11/1977) = -1.28 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In FEET above: Stamping or Designation MLLW MHW 5769 A 1977 4.66 2.88 5769 B 1977 4.69 2.91 5769 C 1977 4.65 2.87 UNSTAMPED 19.16 17.38 MYAKKA 1981 15.74 13.96
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 4 PUBLICATION DATE: 10/22/1984 Station ID: 8725769 SUPERCEDED DATE: 04/21/2003 Name: EL JOBEAN, MYAKKA RIVER FLORIDA NOAA Chart: 11426 Latitude: 26° 57.7' N USGS Quad: EL JOBEAN Longitude: 82° 12.6' 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.