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

                                                                                
Station ID: 9455760                         PUBLICATION DATE:  06/27/2018
Name:       NIKISKI, COOK INLET                               
            AK
NOAA Chart: 16660                           Latitude:   60° 41.0' N (  60.68331)
USGS Quad:  KENAI C4                        Longitude: 151° 23.9' W (-151.39800)


To reach the tidal bench marks from the town of Soldotna, take Route 1 north to
Kenai, continue north past Kenai approximately 16 km (10 mi) until an area of
numerous oil refineries is reached, and proceed past the Phillips 66 refinery to
the Tesoro pipeline wharf located behind the Trading Bay Enterprises and Machine
Company. The bench marks are located in the general vicinity along the road
leading to the pier from the main gate. The tide gauges are located inside a
pumping control hut at the south inside corner of the wharf T section.


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


                 PRIMARY BENCH MARK STAMPING:  5760 L 1983
                         DESIGNATION:          945 5760 L

MONUMENTATION:           Tidal Station disk                    VM#:         1329
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID#: BBBB48
LATITUDE:   60° 41.1' N (  60.68419)          LONGITUDE: 151° 23.6' W (-151.39261)


The primary bench mark is a disk located at the head of the KPL dock for the
Tesoro Refinery in the middle of a gravel area next to a telephone pole, 23.50 m
(77.1 ft) ENE of the NE corner of a 5.80 m x 1.70 m x 2.60 m (19.0 ft x 5.5 ft x
8.5 ft) high grey utility building with six doors on the east wall, a detached
tin roof and surrounded by a black bull rail, 15.20 m (49.9 ft) NW of telephone
pole #P3A, 0.80 m (2.5 ft) east of telephone pole #P3 with a white witness sign
attached, and 0.63 m (2.1 ft) NNE of a 4 in x 4 in wooden post .  The bench mark
is set 0.20 m (0.7 ft) below grade, crimped to the top of a copper clad rod
driven to a depth of 12.20 m (40.0 ft) and encased in a 6-inch PVC pipe and
aluminum logo cover which projects 0.10 m (0.3 ft) above the natural grade.

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

                                                                                
Station ID: 9455760                         PUBLICATION DATE:  06/27/2018
Name:       NIKISKI, COOK INLET                               
            AK
NOAA Chart: 16660                           Latitude:   60° 41.0' N (  60.68331)
USGS Quad:  KENAI C4                        Longitude: 151° 23.9' W (-151.39800)


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


                         BENCH MARK STAMPING:  5760 M 1983
                         DESIGNATION:          945 5760 M

MONUMENTATION:           Tidal Station disk                    VM#:         1330
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   60° 41.1' N (  60.68483)          LONGITUDE: 151° 23.5' W (-151.39186)


The benchmark is a disk set along the north side of the gravel road leading to
the KPL Oil Pier for Tesoro Refinery between telephone poles No.  P5 and P6,
17.1 m (56.1 ft) NE of telephone pole #P5, 15.8 m (51.8 ft) SW of telephone pole
#P6, 7 m (23 ft) NW of the gravel road centerline, and 0.3 m (1 ft) SE of an
orange NOS witness post and sign directly below the power lines.  The benchmark
is set 19 cm (0.6 ft) below grade, crimped to a copper-clad rod driven 14.6 m
(48 ft), and encased in a 4-inch PVC pipe with a logo cap and concrete kick
block projecting 0.1 m (0.3 ft) above the natural grade.

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

                                                                                
Station ID: 9455760                         PUBLICATION DATE:  06/27/2018
Name:       NIKISKI, COOK INLET                               
            AK
NOAA Chart: 16660                           Latitude:   60° 41.0' N (  60.68331)
USGS Quad:  KENAI C4                        Longitude: 151° 23.9' W (-151.39800)


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


                         BENCH MARK STAMPING:  5760 N 1983
                         DESIGNATION:          945 5760 N TIDAL

MONUMENTATION:           Bench Mark disk                       VM#:         1331
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AB7148
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID#: AB7148
LATITUDE:   60° 41.2' N (  60.68650)          LONGITUDE: 151° 23.3' W (-151.38842)


The bench mark is a disk set along the northern side of the road leading to the
KPL oil pier at the Tesoro Refinery, 20.25 m (66.4 ft) south of the road running
north and south, 9.90 m (32.5 ft) SE of 16-inch steel pipes parallel with the
ground, 8.20 m (26.9 ft) NW of the centerline of the gravel road leading to KPL
dock, and 1.20 m (3.9 ft) NW of telephone pole #P14 with a white NOS witness
post sign attached.  The bench mark is set 0.10 m (0.3 ft) below grade, crimped
to the top of a copper clad rod driven 7.00 m (23.0 ft) to refusal and encased
in a 4-inch PVC pipe which is encased in a 6-inch PVC pipe with logo cover.



                         BENCH MARK STAMPING:  5760 P 2002
                         DESIGNATION:          945 5760 P

MONUMENTATION:           Tidal Station disk                    VM#:        16837
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete pier support                 OPUS PID:        
LATITUDE:   60° 41.0' N (  60.68353)          LONGITUDE: 151° 23.7' W (-151.39514)


The bench mark is a disk set flush on top of the 12th concrete support from the
inshore end on the south side of the KPL dock, 5.60 m (18.4 ft) east of the
first expansion joint in pier, 2.30 m (7.5 ft) south of centerline of causeway,
and 0.20 m (0.7 ft) below the pier deck.

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

                                                                                
Station ID: 9455760                         PUBLICATION DATE:  06/27/2018
Name:       NIKISKI, COOK INLET                               
            AK
NOAA Chart: 16660                           Latitude:   60° 41.0' N (  60.68331)
USGS Quad:  KENAI C4                        Longitude: 151° 23.9' W (-151.39800)


                            T I D A L   D A T U M S 


Tidal datums at NIKISKI, COOK INLET based on:

     LENGTH OF SERIES:      19 YEARS
     TIME PERIOD:           Oct 1996 - Sep 2010 & July 2012 - June 2017
     TIDAL EPOCH:           2012-2016
     CONTROL TIDE STATION:  9455500 SELDOVIA, COOK INLET


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

     HIGHEST OBSERVED WATER LEVEL (12/26/1976)         =  8.657
     MEAN HIGHER HIGH WATER                     MHHW   =  6.262
     MEAN HIGH WATER                            MHW    =  6.039
     MEAN SEA LEVEL                             MSL    =  3.442
     MEAN TIDE LEVEL                            MTL    =  3.345
     North American Vertical Datum              NAVD88 =  2.205
     MEAN LOW WATER                             MLW    =  0.650
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (12/14/2008)         = -1.925

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     5760 L 1983                                12.839    6.800
     5760 M 1983                                13.193    7.154
     5760 N 1983                                26.359   20.320
     5760 P 2002                                10.652    4.613


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

                                                                                
Station ID: 9455760                         PUBLICATION DATE:  06/27/2018
Name:       NIKISKI, COOK INLET                               
            AK
NOAA Chart: 16660                           Latitude:   60° 41.0' N (  60.68331)
USGS Quad:  KENAI C4                        Longitude: 151° 23.9' W (-151.39800)


                             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.