U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 07/24/1984
Station ID: 8727001 SUPERCEDED DATE: 04/21/2003
Name: MIDDLE PITHLACHASCOTEE RIVER
FLORIDA
NOAA Chart: 11409 Latitude: 28° 14.9' N
USGS Quad: ELFERS Longitude: 82° 43.4' W
To reach the tidal bench marks from the intersection of U.S. Highway 19 and west
Main Street in New Port Richey, proceed 0.25 mile (0.40 km) east along west Main
Street to South River Road, then south on South River Road for 0.15 mile (0.24
km) to 410 South River Road. The bench marks are located in the area around the
concrete bridge. The tide gage and staff were located on a private pier behind
the residence at 410 South River Road.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7001 A 1976
MONUMENTATION: Survey Disk VM#: 7701
AGENCY: PID#: AL7450
SETTING CLASSIFICATION: Concrete Step
The bench mark is set flush in the first concrete step of the First Church of
Christ, 55.6 feet (16.9 m) west of the centerline of South River Road, 35 feet
(11 m) NE of the SE corner of the church, and 20 feet (6 m) east of the front of
the church.
BENCH MARK STAMPING: 7001 B 1976
MONUMENTATION: Survey Disk VM#: 7702
AGENCY: PID#: AL7449
SETTING CLASSIFICATION: Copper-Coated Steel Rod
The bench mark is located 99 feet (30 m) north of the curve of West Main Street,
57 feet (17 m) west of the NW corner of the Chamber of Commerce, 25.6 feet (7.8
m) east of the centerline of North River Road and 5.5 feet (1.7 m) NE of a power
pole. The bench mark is 0.6 foot (0.2 m) below ground level, crimped to a
copper-coated steel rod driven 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 4
PUBLICATION DATE: 07/24/1984
Station ID: 8727001 SUPERCEDED DATE: 04/21/2003
Name: MIDDLE PITHLACHASCOTEE RIVER
FLORIDA
NOAA Chart: 11409 Latitude: 28° 14.9' N
USGS Quad: ELFERS Longitude: 82° 43.4' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7001 C 1976
MONUMENTATION: Survey Disk VM#: 7703
AGENCY: PID#: AL7448
SETTING CLASSIFICATION: Concrete Slab
The bench mark is set flush in a concrete slab, 136 feet (41 m) NNE of Bench
Mark 7001 B 1976, 106 feet (32 m) NNW of NE corner of the Chamber of Commerce,
66.5 feet (20.3 m) east of the centerline of North River Road, 1.8 feet (0.5 m)
north of south end of a concrete slab and 1.4 feet (0.4 m) west of the east side
of a concrete slab.
BENCH MARK STAMPING: UNSTAMPED 1
MONUMENTATION: Survey Disk VM#: 7704
AGENCY: PID#: AL7447
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set in the NE corner of the West Main Street concrete bridge,
33.5 feet (10.2 m) north of the centerline of the bridge, and 1.5 feet (0.5 m)
SE of the NE corner of the bridge.
BENCH MARK STAMPING: UNSTAMPED 2
MONUMENTATION: Survey Disk VM#: 7705
AGENCY: PID#: AL7446
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set in the SW corner of the West Main Street concrete bridge,
33.5 feet (10.2 m) south of the centerline of the bridge and 1.5 feet (0.5 m) NE
of the SW corner of the bridge.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 07/24/1984
Station ID: 8727001 SUPERCEDED DATE: 04/21/2003
Name: MIDDLE PITHLACHASCOTEE RIVER
FLORIDA
NOAA Chart: 11409 Latitude: 28° 14.9' N
USGS Quad: ELFERS Longitude: 82° 43.4' W
T I D A L D A T U M S
Tidal datums at MIDDLE PITHLACHASCOTEE RIVER based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: MARCH 1976
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8726724 CLEARWATER BEACH
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (04/16/1976) = 4.17
MEAN HIGHER HIGH WATER MHHW = 3.40
MEAN HIGH WATER MHW = 2.99
MEAN TIDE LEVEL MTL = 1.77
MEAN LOW WATER MLW = 0.55
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (02/14/1976) = -0.89
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
7001 A 1976 13.31 10.32
7001 B 1976 9.20 6.21
7001 C 1976 8.32 5.33
UNSTAMPED 1 14.74 11.75
UNSTAMPED 2 14.58 11.59
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 07/24/1984
Station ID: 8727001 SUPERCEDED DATE: 04/21/2003
Name: MIDDLE PITHLACHASCOTEE RIVER
FLORIDA
NOAA Chart: 11409 Latitude: 28° 14.9' N
USGS Quad: ELFERS Longitude: 82° 43.4' 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.