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Bench Mark Sheet for 9414811, Bradmoor Island CA

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                                                
Station ID: 9414811                         PUBLICATION DATE:  07/14/2009
Name:       BRADMOOR ISLAND, NURSE SLOUGH                     
            CA
NOAA Chart: 18652                           Latitude:   38° 11.0' N (  38.18330)
USGS Quad:  DENVERTON                       Longitude: 121° 55.4' W (-121.92300)


To reach the tidal bench marks from Interstate 80, take the North Texas (Highway
12 East) exit in Fairfield, 19.3 km (12.0 mi) east on Highway 12 to Shiloh Road,
south on Shiloh Road for 3.2 km (2.0 mi) to Little Honker Bay Road, at Honker
Road turn west through middle of 3 gates, then gravel road to the top of the
Island, left fork to Rogers Duck Club at the top of the hill.  The tide gage was
located at end of the pier behind the sheet metal shack.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  4811 C 1978
                         DESIGNATION:          941 4811 C

MONUMENTATION:           Tidal Station disk                    VM#:        11917
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   38° 11.0' N (  38.18330)          LONGITUDE: 121° 55.4' W (-121.92300)


The primary bench mark is a disk located 193.24 m (634.0 ft) east along levee
road from wooden bridge at Rogers Duck Club, 2.74 m (9.0 ft) north of the
centerline of levee road, and 0.85 m (2.8 ft) west of witness post.  The bench
mark is set 0.06 m (0.2 ft) below grade, set on a copper rod driven 12.2 m (40
ft) to refusal, and encased in a PVC pipe that extends 0.15 m (0.5 ft) above
grade.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 9414811                         PUBLICATION DATE:  07/14/2009
Name:       BRADMOOR ISLAND, NURSE SLOUGH                     
            CA
NOAA Chart: 18652                           Latitude:   38° 11.0' N (  38.18330)
USGS Quad:  DENVERTON                       Longitude: 121° 55.4' W (-121.92300)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  4811 B 1978
                         DESIGNATION:          941 4811 B

MONUMENTATION:           Tidal Station disk                    VM#:        11916
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   38° 11.0' N (  38.18330)          LONGITUDE: 121° 55.4' W (-121.92300)


The bench mark is a disk located 80.47 m (264.0 ft) east along levee road from
wooden bridge at Rogers Duck Club, 2.38 m (7.8 ft) south of centerline of levee
road, and 1.01 m (3.3 ft) east of witness post.  The bench mark is set 0.06 m
(0.2 ft) below grade, set on a copper rod driven 12.2 m (40 ft) to refusal, and
encased in a PVC pipe which extends 0.06 m (0.2 ft) above grade.



                         BENCH MARK STAMPING:  4811 D 1978
                         DESIGNATION:          941 4811 D

MONUMENTATION:           Tidal Station disk                    VM#:        11918
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   38° 11.0' N (  38.18330)          LONGITUDE: 121° 55.4' W (-121.92300)


The bench mark is a disk located 0.3 km (0.2 mi) east along levee road from
wooden bridge at Rogers Duck Club, 3 m (10 ft) east of the centerline of levee
road, and 1.22 m (4.0 ft) south of witness post.   The bench mark is set 0.06 m
(0.2 ft) below grade, set on a copper rod driven 12.2 m (40 ft) to refusal, and
encased in a PVC pipe which extends 0.21 m (0.7 ft) above grade.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 9414811                         PUBLICATION DATE:  07/14/2009
Name:       BRADMOOR ISLAND, NURSE SLOUGH                     
            CA
NOAA Chart: 18652                           Latitude:   38° 11.0' N (  38.18330)
USGS Quad:  DENVERTON                       Longitude: 121° 55.4' W (-121.92300)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  4811 F 2004
                         DESIGNATION:          941 4811 F

MONUMENTATION:           Flange-encased Rod                    VM#:        17602
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod in sleeve         OPUS PID:        
LATITUDE:   38° 11.0' N (  38.18330)          LONGITUDE: 121° 55.4' W (-121.92300)


The bench mark is set in a sandstone outcrop located on Bradmoor Island just
north of the pier, 0.76 m (2.5ft) south of a 3 trunk Eucalyptus tree and  0.12m
(0.4ft) SW of NOAA witness post.  The datum point is set 0.1 m (0.3 ft) below
grade, the top of a stainless steel rod driven 3 m (10 ft) to refusal, in a
sleeve extending to an unspecified depth and encased in a 5-inch NOS logo cap.  
     



                         BENCH MARK STAMPING:  4811 G 2004
                         DESIGNATION:          941 4811 G

MONUMENTATION:           Tidal Station disk                    VM#:        17603
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Sandstone outcrop                     OPUS PID#: BBCQ20
LATITUDE:   38° 11.0' N (  38.18330)          LONGITUDE: 121° 55.4' W (-121.92300)


The bench mark is a disk set in a sandstone outcrop located on Bradmoor Island
along the slough west of the pier,  56.3 m (185 ft) south of the SW corner of
club house, 18.6 m (61ft) NW of NW corner of storage building on pier, 4.6 m (15
ft) SW of top of bank and 0.3 m (1 ft) SE of foot high white post.              

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 9414811                         PUBLICATION DATE:  07/14/2009
Name:       BRADMOOR ISLAND, NURSE SLOUGH                     
            CA
NOAA Chart: 18652                           Latitude:   38° 11.0' N (  38.18330)
USGS Quad:  DENVERTON                       Longitude: 121° 55.4' W (-121.92300)


                            T I D A L   D A T U M S 


Tidal datums at BRADMOOR ISLAND, NURSE SLOUGH based on:

     LENGTH OF SERIES:      16 MONTHS
     TIME PERIOD:           April 2004 - July 2005
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9415144 PORT CHICAGO, SUISUN BAY


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     HIGHEST OBSERVED WATER LEVEL (01/08/2005)         =  2.233
     MEAN HIGHER HIGH WATER                     MHHW   =  1.672
     MEAN HIGH WATER                            MHW    =  1.512
     MEAN SEA LEVEL                             MSL    =  0.883
     MEAN TIDE LEVEL                            MTL    =  0.871
     MEAN LOW WATER                             MLW    =  0.229
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (04/22/2004)         = -0.305

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     4811 C 1978                                 1.487   -0.025
     4811 B 1978                                 2.090    0.578
     4811 D 1978                                 0.801   -0.711
     4811 F 2004                                 1.687    0.175
     4811 G 2004                                 1.932    0.420


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                                                
Station ID: 9414811                         PUBLICATION DATE:  07/14/2009
Name:       BRADMOOR ISLAND, NURSE SLOUGH                     
            CA
NOAA Chart: 18652                           Latitude:   38° 11.0' N (  38.18330)
USGS Quad:  DENVERTON                       Longitude: 121° 55.4' W (-121.92300)


                             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.

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Revised: 08/08/2018
NOAA / National Ocean Service
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