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

                                                                                
Station ID: 9044030                         PUBLICATION DATE:  08/11/2017
Name:       WYANDOTTE, DETROIT RIVER                          
            MI
NOAA Chart: 14848                           Latitude:   42° 12.1' N (  42.20231)
USGS Quad:                                  Longitude:  83°  8.8' W ( -83.14750)


TO REACH THE NOS GAUGING STATION, IN WYANDOTTE, WAYNE COUNTY, MICHIGAN, FROM THE
INTERSECTION OF BIDDLE AVE AND FORD AVE, PROCEED SOUTH ON BIDDLE AVE FOR APPROX
0.8 MILE (1.3 KM) TO THE INTERSECTION WITH MAPLE ST, THEN PROCEED EAST ON MAPLE
ST FOR APPROX 0.1 MILE (0.2 KM) TO THE INTERSECTION WITH VAN ALSTYNE BLVD, THEN
PROCEED NORTH ON VAN ALSTYNE BLVD FOR APPROX 0.1 MILE (0.2 KM) TO RESIDENCE AT
3025 VAN ALSTYNE BLVD, ON EAST SIDE OF BLVD IN THE REAR OF THE PROPERTY, THEN
ABOUT 64 METERS (210.0 FT) SOUTHEAST OF THE INTERSECTION OF VAN ALSTYNE
BOULEVARD AND ELM STREET, 7.6 METERS (24.9 FT) WEST OF THE WEST EDGE OF THE
DETROIT RIVER.


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


                 PRIMARY BENCH MARK STAMPING:  CHIEF
                         DESIGNATION:          904 4030 CHIEF

MONUMENTATION:           Survey disk                           VM#:        12943
AGENCY:                  US Lake Survey                        IDB PID#:  NE0577
SETTING CLASSIFICATION:  Gauge house foundation                OPUS PID:        
LATITUDE:   42° 12.1' N (  42.20244)          LONGITUDE:  83°  8.8' W ( -83.14747)


The bench mark is a disk 64 m (210.0 ft) SE of the intersection of Van Alstyne
Boulevard and Elm Street, 7.6 m (24.9 ft) W of W edge of the Detroit River, 0.2
m (0.7 ft) NNW  of the SW corner of the gauge house, near the SW corner of the
concrete foundation of the NOS water level gauging station, being highest point
over cross at center of bronze disc set into the concrete foundation.

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

                                                                                
Station ID: 9044030                         PUBLICATION DATE:  08/11/2017
Name:       WYANDOTTE, DETROIT RIVER                          
            MI
NOAA Chart: 14848                           Latitude:   42° 12.1' N (  42.20231)
USGS Quad:                                  Longitude:  83°  8.8' W ( -83.14750)


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


                         BENCH MARK STAMPING:  BANK CBF 1963
                         DESIGNATION:          904 4030 BANK

MONUMENTATION:           Survey disk                           VM#:        12944
AGENCY:                  US Lake Survey                        IDB PID#:  NE0579
SETTING CLASSIFICATION:  Building                              OPUS PID:        
LATITUDE:   42° 12.2' N (  42.20292)          LONGITUDE:  83°  8.9' W ( -83.14886)


The bench mark is a disc on the E face of the Wyandotte Municipal Center,
formerly known as the Wyandotte Savings Bank, (3005 Biddle Ave, in back of bldg
with unmarked alleyway), midway between the sills of the N pair of windows, 11.7
m (38.4 ft) N of a power pole with light no. SW-S-5-45, 2.8 m (9.2 ft) S of the
NE corner of building, 1.12 m (3.67 ft) above the alley pavement, being
horizontal line of cross on bronze disc set vertically into the brick wall.



                         BENCH MARK STAMPING:  D 44 1930 MCK
                         DESIGNATION:          904 4030 D 44

MONUMENTATION:           Survey disk                           VM#:        12945
AGENCY:                  US Lake Survey                        IDB PID#:  NE0580
SETTING CLASSIFICATION:  Building                              OPUS PID:        
LATITUDE:   42° 12.2' N (  42.20406)          LONGITUDE:  83°  8.9' W ( -83.14872)


The bench mark is a disc at the intersection of Biddle Ave and Oak St, on the S
side of Oak St and the E side of Biddle Ave, then 14.5 m (47.6 ft) S of S curb
of Oak St, 6.25 m (20.51 ft) E of E curb of Biddle Ave, 0.12 m (0.39 ft) N of SW
corner of building and 1.0 m (3.3 ft) above level of side walk, set vertically
in the W face of bldg number (2903 Biddle Ave).

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

                                                                                
Station ID: 9044030                         PUBLICATION DATE:  08/11/2017
Name:       WYANDOTTE, DETROIT RIVER                          
            MI
NOAA Chart: 14848                           Latitude:   42° 12.1' N (  42.20231)
USGS Quad:                                  Longitude:  83°  8.8' W ( -83.14750)


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


                         BENCH MARK STAMPING:  4030 G 1993
                         DESIGNATION:          904 4030 G

MONUMENTATION:           Bench Mark disk                       VM#:        12946
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AA9378
SETTING CLASSIFICATION:  Stainless steel rod w/o sleeve        OPUS PID:        
LATITUDE:   42° 12.2' N (  42.20397)          LONGITUDE:  83°  8.8' W ( -83.14719)


The bench mark is a disc 29.4 m (96.5 ft) W of the SW corner of veterans
memorial statue, 16.0 m (52.5 ft) NW of the NE corner of a parking lot, 12.6 m
(41.3 ft) ESE of center line of Van Alstyne Blvd., 10.0 m (32.8 ft) NE of center
line of oak street, BM is .09 m (0.30 ft) below ground encased in a 5-inch PVC
pipe with aluminum access cover with witness post.



                         BENCH MARK STAMPING:  4030 K 2010
                         DESIGNATION:          904 4030 K

MONUMENTATION:           Metal Rod                             VM#:        19808
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Steel rod driven to refusal           OPUS PID#: BBDY81
LATITUDE:   42° 12.2' N (  42.20389)          LONGITUDE:  83°  8.8' W ( -83.14717)


The bench mark is a steel rod 25.32 m SW of a grey stone veterans memorial
monument, 21.49 m WNW of the bulkhead wall on the W shore of the Detroit River,
5.87 m SE of a curb in the NE corner of the city parking lot, BM is 0.14 m below
ground encased in a 5-inch PVC pipe with aluminum access cover with witness
post.





Foot Notes:

Above marks are published for informational purposes only.  Long term stability
has not been reviewed prior to publication.

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

                                                                                
Station ID: 9044030                         PUBLICATION DATE:  08/11/2017
Name:       WYANDOTTE, DETROIT RIVER                          
            MI
NOAA Chart: 14848                           Latitude:   42° 12.1' N (  42.20231)
USGS Quad:                                  Longitude:  83°  8.8' W ( -83.14750)


                             D E F I N I T I O N S


The International Great Lakes Datum (IGLD) is the vertical height reference
datum used in the Great Lakes/St. Lawrence River System for engineering,
charting, channel dredging, navigation safety, power generation, and water 
resource management. It is a coordinated datum between the United States and
Canada that ensures both countries are using the same reference for projects
in the Great Lakes basin. The datum origin, or zero, is defined as Mean Sea 
Level at Pointe-au-Pere /Rimouski, Quebec, Canada at the mouth of the 
St. Lawrence River. IGLD requires updating approximately every 25-30 years 
to account for varying changes in the land surface elevations following the 
retreat of the glaciers during the last ice age, referred to as Glacial 
Isostatic Adjustment (GIA). The current IGLD 1985 was implemented in 1992.

IGLD 1985 uses dynamic heights as the vertical reference standard and lakes
station water level elevations are adjusted to provide a level geopotential
plane for lake level reference.

Dynamic height is the potential difference along the plumbline between the 
vertical datum and a point of interest divided by a constant value of 
gravity. In Canada and USA, the constant value of gravity is the 
"normal gravity" on the ellipsoid at latitude 45° (9.806199 ms-2). Dynamic 
heights have no geometric meaning. They are mainly used for the management 
of water in large lakes, rivers and channels. The surface of a lake has a 
constant dynamic height if undisturbed by currents, winds, atmospheric 
pressure, etc.

The Hydraulic Corrector (HC) is the difference in the long term water level 
mean between Subordinate and Master station. The difference (HC) is 
subtracted algebraically at the subordinate gauge referencing the same 
elevation as the master station. Thus all water levels on a given lake can 
be referenced to the same lakes LWD/Chart Datum reference elevation.

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

                                                                                
Station ID: 9044030                         PUBLICATION DATE:  08/11/2017
Name:       WYANDOTTE, DETROIT RIVER                          
            MI
NOAA Chart: 14848                           Latitude:   42° 12.1' N (  42.20231)
USGS Quad:                                  Longitude:  83°  8.8' W ( -83.14750)


                             D E F I N I T I O N S


A Master Stations is the control point for determining water level 
elevations on a particular lake of the Great Lakes.   Since water surfaces
of the Great Lakes are considered to be at geopotential equal, all Mean 
Water Level (MWL) values for stations on a particular lake should have the 
same dynamic height.  Therefore, all subordinate water level station MWL 
values are adjusted to match the dynamic water level elevation of the Master
Station through the use of a hydraulic corrector.  In the establishment of 
International Great Lakes Datum (1985) the connecting waterways station 
dynamic elevations were calculated through the use of a linear regression 
while constraining the end points of the regression with the dynamic 
elevations of the corresponding master station above and below the 
connecting channel.

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 toNAVD88 are available from NGS through the World Wide 
Web at National Geodetic Survey.

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/.