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

                                                   PUBLICATION DATE:  05/19/1982
Station ID: 9414867                                SUPERCEDED DATE:   04/21/2003
Name:       BORDEN HIGHWAY BRIDGE, SANJOAQUIN RIVER           
            CALIFORNIA
NOAA Chart: 18661                                  Latitude:         38° 56.2' N
USGS Quad:  STOCKTON                               Longitude:       121° 20.0' W


To reach the tidal bench marks proceed east on Highway 4 towards Stockton,
stopping just before the bridge over San Joaquin River, left off road through a
gate into sewage pond yard, east to southeast corner of yard then north along
levee road on west bank of river to Bascule Railroad bridge.  The tide gage and
staff were located on the railroad bridge.


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


                 PRIMARY BENCH MARK STAMPING:  4867 A 1978

MONUMENTATION:           Survey Disk                               VM#:    10575
AGENCY:                                                            PID#:  AE9895
SETTING CLASSIFICATION:  Copper-Coasted Steel Rod


The bench mark is set on a copper rod driven 47 feet to refusal, encased in PVC
pipe and concrete (extends 1.4 feet above grade), along gravel road at east edge
of Stockton Tertiary Sewage Pond yard, at intersection of San Joaquin River and
at the Southern Pacific Company railway tracks, 9 feet east northeast of
centerline of gravelled levee road on west side of San Joaquin River, and 3 feet
west northwest of witness post.



                         BENCH MARK STAMPING:  4867 C 1978

MONUMENTATION:           Survey Disk                               VM#:     8467
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Copper-Coated Steel Rod


The bench mark is set on a copper rod driven 46 feet to refusal, encased in PVC
and concrete (extends 0.8 foot above grade), along gravelled road at east edge
of Stockton Sewage Pond yard north of Highway 4, west of San Joaquin River, 190
feet east of sheet metal pumphouse, and 12 feet north of centerline of gravelled
road on south side of the river

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

                                                   PUBLICATION DATE:  05/19/1982
Station ID: 9414867                                SUPERCEDED DATE:   04/21/2003
Name:       BORDEN HIGHWAY BRIDGE, SANJOAQUIN RIVER           
            CALIFORNIA
NOAA Chart: 18661                                  Latitude:         38° 56.2' N
USGS Quad:  STOCKTON                               Longitude:       121° 20.0' W


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


                         BENCH MARK STAMPING:  SJ 141 BM 1955 SACTO DIST

MONUMENTATION:           Survey Disk                               VM#:     8468
AGENCY:                                                            PID#:  HS0440
SETTING CLASSIFICATION:  Concrete Curb


The bench mark is set in top of east end of south concrete curb, 2 miles west
along State Highway 4 from Southern Pacific railroad overpass at Stockton, at
Garwood Bridge over the river, 15 feet south of centerline of highway, 2 feet
north of north face of south concrete guardrail, and 0.5 foot above level of
highway.



                         BENCH MARK STAMPING:  NO 1 1934

MONUMENTATION:           Survey Disk                               VM#:    10572
AGENCY:                                                            PID#:  HS0441
SETTING CLASSIFICATION:  Abutment of Bridge


The bench mark is set in top of northeast corner of the east abutment of Garwood
Bridge over San Joaquin River, 3 miles west along State Highway 4 from Southern
Pacific Company Railroad overpass at Stockton, 26.5 feet west of centerline of
black top road leading north along top of levee, 15 feet north of centerline of
highway, and level with highway.



                         BENCH MARK STAMPING:  NO 2 1934

MONUMENTATION:           Survey Disk                               VM#:    10573
AGENCY:                                                            PID#:  HS0439
SETTING CLASSIFICATION:  Abutment of Bridge


The bench mark is set in top of northeast corner of the west abutment of Garwood
Bridge over San Joaquin River, 3 miles west along State Highway 4 from Southern
Pacific Company Railroad overpass at Stockton, 17 feet east of center of west
levee, 15 feet north of centerline of highway, 0.7 foot north of north edge of
concrete pillar, and level with highway.

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

                                                   PUBLICATION DATE:  05/19/1982
Station ID: 9414867                                SUPERCEDED DATE:   04/21/2003
Name:       BORDEN HIGHWAY BRIDGE, SANJOAQUIN RIVER           
            CALIFORNIA
NOAA Chart: 18661                                  Latitude:         38° 56.2' N
USGS Quad:  STOCKTON                               Longitude:       121° 20.0' W


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


                         BENCH MARK STAMPING:  NO 5 1948

MONUMENTATION:           Survey Disk                               VM#:    10574
AGENCY:                                                            PID#:  HS0442
SETTING CLASSIFICATION:  Concrete Guardrail


The bench mark is set in top of west end of north concrete guardrail at concrete
bridge N0-20-51 over a dirt road, 3 miles west along State Highway 4 from
Southern Pacific Company Railroad overpass at Stockton, 103 feet east of east
end of Garwood Bridge, 103 feet east of Bench Mark N0 1 1934, 54.5 feet east of
centerline of black top road leading north along levee, 14.5 feet north of
centerline of highway, and 2.5 feet above level of highway.



                         BENCH MARK STAMPING:  4867 B 1978

MONUMENTATION:           Survey Disk                               VM#:    10576
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Copper-Coated Steel Rod


The bench mark is set on a copper rod driven 42 feet to refusal, encased in PVC
pipe (extends 1.2 feet above grade), along gravel road at east edge of Stockton
Tertiary Sewage Pond yard north of Highway 4, 434 feet southeast along levee
road from Bench Mark 4867 A 1978, 285 feet west northwest of sheet metal
pumphouse, 8 feet north of centerline of gravelled levee road on south bank of
river, and 3 feet west of witness post.

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

                                                   PUBLICATION DATE:  05/19/1982
Station ID: 9414867                                SUPERCEDED DATE:   04/21/2003
Name:       BORDEN HIGHWAY BRIDGE, SANJOAQUIN RIVER           
            CALIFORNIA
NOAA Chart: 18661                                  Latitude:         38° 56.2' N
USGS Quad:  STOCKTON                               Longitude:       121° 20.0' W


                            T I D A L   D A T U M S 


Tidal datums at BORDEN HIGHWAY BRIDGE, SANJOAQUIN RIVER based on:

     LENGTH OF SERIES:      12 MONTHS
     TIME PERIOD:           SEPTEMBER1978-SEPTEMBER 1979
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:   


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

     MEAN HIGHER HIGH WATER                     MHHW   =   3.65
     MEAN HIGH WATER                            MHW    =   3.22
     MEAN TIDE LEVEL                            MTL    =   1.83
     MEAN LOW WATER                             MLW    =   0.44
   * NATIONAL GEODETIC VERTICAL DATUM           NGVD29 =   0.03
     MEAN LOWER LOW WATER                       MLLW   =   0.00

   * NGVD reference based on adjustment of 1967 and NOS levels of1978-1979. 
North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     4867 A 1978                                18.20     14.98
     4867 C 1978                                18.79     15.57
     SJ 141 BM 1955 SACTO DIST                  24.43     21.21
     NO 1 1934                                  23.59     20.37
     NO 2 1934                                  23.96     20.74
     NO 5 1948                                  24.96     21.74
     4867 B 1978                                17.87     14.65


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

                                                   PUBLICATION DATE:  05/19/1982
Station ID: 9414867                                SUPERCEDED DATE:   04/21/2003
Name:       BORDEN HIGHWAY BRIDGE, SANJOAQUIN RIVER           
            CALIFORNIA
NOAA Chart: 18661                                  Latitude:         38° 56.2' N
USGS Quad:  STOCKTON                               Longitude:       121° 20.0' 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.