U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  9

                                                                                
Station ID: 9063063                         PUBLICATION DATE:  08/11/2017
Name:       CLEVELAND, LAKE ERIE                              
            OH
NOAA Chart: 14839                           Latitude:   41° 32.5' N (  41.54086)
USGS Quad:                                  Longitude:  81° 38.1' W ( -81.63547)


TO REACH THE NOS GAUGING STATION IN CLEVELAND, CUYAHOGA COUNTY, OHIO, FROM THE
INTERSECTION OF HWY 90/2 AND MARTIN LUTHER KING JR BLVD, PROCEED ON M.L. KING JR
BLVD TO ITS INTERSECTION WITH N MARGINAL DRIVE, THEN PROCEED WEST ON N MARGINAL
DR FOR APPROX 0.05 MILE (0.08 KM) TO THE ENTRANCE, ON THE NORTH SIDE OF DRIVE,
TO THE LAKEFRONT STATE PARK AND GORDON BOAT RAMP, BETWEEN THE NORTH END OF E
72ND STREET AND M.L. KING JR. BOULEVARD, THEN PROCEED NW ON PAVED ENTRANCE RD
FOR APPROX 0.15 MILE (0.241 KM) TO THE NOS GAUGE HOUSE.


                    G R E A T  L A K E S   B E N C H   M A R K S
                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  9

                                                                                
Station ID: 9063063                         PUBLICATION DATE:  08/11/2017
Name:       CLEVELAND, LAKE ERIE                              
            OH
NOAA Chart: 14839                           Latitude:   41° 32.5' N (  41.54086)
USGS Quad:                                  Longitude:  81° 38.1' W ( -81.63547)


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


                 PRIMARY BENCH MARK STAMPING:  G 321 1981
                         DESIGNATION:          G 321

MONUMENTATION:           Flange-encased Rod                    VM#:        12817
AGENCY:                  National Geodetic Survey              IDB PID#:  MB1563
SETTING CLASSIFICATION:  Stainless steel rod in sleeve         OPUS PID:        
LATITUDE:   41° 32.4' N (  41.54000)          LONGITUDE:  81° 38.1' W ( -81.63417)


The benchmark is a stainless steel rod 117.34m (384.97 ft) SSE of the NOS gauge
house (a 7 foot (2.1 m) square brick building) , 40.78m (133.79 ft) S of an
aluminum lamp post, 16.10m (52.82 ft) SE of the SE edge of the sidewalk leading
into the park, 11.37m (37.30 ft) S of a paved bike path, with 5-inch PVC pipe
and aluminum access cover which is stamped "G 321" surrounded by a mass of
concrete flush with the ground.  Marked with witness post.



                         BENCH MARK STAMPING:  906 3063 STEPS
                         DESIGNATION:          906 3063 STEPS

MONUMENTATION:           Metal Rod                             VM#:        12818
AGENCY:                  National Geodetic Survey              IDB PID#:  MB1562
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   41° 32.4' N (  41.53967)          LONGITUDE:  81° 38.0' W ( -81.63361)


The bench mark is a copper-clad steel rod W of the bottom step of the concrete
stairs leading uphill to a public bridge crossing over Interstate 90 for access
to Gordon City Park and Aquarium, 19.20m (62.99 ft) W of a telephone pole marked
"TLCOB 2nd.V790", 2.15m (7.05 ft) S of the S curb of the road, 0.64m (2.10 ft) W
of the concrete retaining wall of the stairs, being a 5/8-inch copper-coated
steel rod, 3.96m (12.99 ft) long.  Note - in 1981 the mark was encased in a
5-inch PVC pipe with an NGS aluminum access cover, stamped "906 3063 Steps". 
Marked with witness post.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  9

                                                                                
Station ID: 9063063                         PUBLICATION DATE:  08/11/2017
Name:       CLEVELAND, LAKE ERIE                              
            OH
NOAA Chart: 14839                           Latitude:   41° 32.5' N (  41.54086)
USGS Quad:                                  Longitude:  81° 38.1' W ( -81.63547)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          906 3063 LIBERTY

MONUMENTATION:           Bolt                                  VM#:        12819
AGENCY:                                                        IDB PID#:  MB1567
SETTING CLASSIFICATION:  Abutment                              OPUS PID:        
LATITUDE:   41° 32.4' N (  41.53942)          LONGITUDE:  81° 37.9' W ( -81.63172)


The bench mark is a brass coated closet bolt set vertically in the N face of the
W abutment of the bridge, 7.62m (25.00 ft) W of the center line of the S-bound
lane of the Blvd, 3.36m (11.02 ft) W of E edge of sidewalk, 2.60m (8.53 ft) S of
a telephone pole marked "SWP 11-85 SPP 3-45", 0.99m (3.25 ft) E of the W inside
corner of abutment, 0.3m  (1.0 ft) W of the E edge of the abutment and 1.57m
(5.15 ft) above the sidewalk.



                         BENCH MARK STAMPING:  3063 F 1979
                         DESIGNATION:          906 3063 F

MONUMENTATION:           Bench Mark disk                       VM#:        12820
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  MB1564
SETTING CLASSIFICATION:  Concrete catch basin                  OPUS PID:        
LATITUDE:   41° 32.4' N (  41.54047)          LONGITUDE:  81° 38.1' W ( -81.63464)


The bench mark is a disk in the top of the NW corner of a concrete catch basin,
which is in a grassy area between the W end of the entrance to the S parking
area for boat launching ramps and an entrance road leading to the boat ramps,
54.75m (179.63 ft) SE of the NW corner of the NOS water level gauging house,
27.28m (89.50 ft) NW of a metal lamp post, and 13.21m (43.34 ft) S of a stop
sign.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  9

                                                                                
Station ID: 9063063                         PUBLICATION DATE:  08/11/2017
Name:       CLEVELAND, LAKE ERIE                              
            OH
NOAA Chart: 14839                           Latitude:   41° 32.5' N (  41.54086)
USGS Quad:                                  Longitude:  81° 38.1' W ( -81.63547)


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


                         BENCH MARK STAMPING:  3063 G 1982
                         DESIGNATION:          906 3063 G

MONUMENTATION:           Bench Mark disk                       VM#:        12821
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AB6923
SETTING CLASSIFICATION:  Concrete foundation of drain          OPUS PID:        
LATITUDE:   41° 32.4' N (  41.54044)          LONGITUDE:  81° 38.0' W ( -81.63361)


The bench mark is a disk on the S edge of most N parking lot, near the
restrooms, in the most N median of the parking lot, 91.1m (298.9 ft) N of
concrete steps going uphill to a public walkway crossing over Interstate 90 for
access to Gordon City Park and Aquarium, 42.35m (138.94 ft) from the W face of
foundation of light post no. G17,  3.28m (10.76 ft) N of the S edge of the S
parking area, 2.8m (9.2 ft) S of the S edge of most N parking area, being the
high point on NOS disc set flush in the W corner of the concrete foundation of
drain, stamped "3063 G 1982".



                         BENCH MARK STAMPING:   
                         DESIGNATION:          906 3063 DON

MONUMENTATION:           Survey disk                           VM#:        12822
AGENCY:                  US Army Corps of Engineers            IDB PID#:  MB1566
SETTING CLASSIFICATION:  Concrete floor                        OPUS PID:        
LATITUDE:   41° 32.5' N (  41.54086)          LONGITUDE:  81° 38.1' W ( -81.63547)


The bench mark is a disk in the top of the concrete floor of the NOS gauge house
(a 7 foot (2.1 m) square brick building) located on the SW side of the boat
launching ramps, 1.75m (5.74 ft) S of the N inside face of the NOS water level
gauging house, 0.3m (1.0 ft) NW of the bottom door sill of the gage house, 0.4m
(1.3 ft) NW of the S inside corner of the gage house.  Note - no stamping on
disk.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  9

                                                                                
Station ID: 9063063                         PUBLICATION DATE:  08/11/2017
Name:       CLEVELAND, LAKE ERIE                              
            OH
NOAA Chart: 14839                           Latitude:   41° 32.5' N (  41.54086)
USGS Quad:                                  Longitude:  81° 38.1' W ( -81.63547)


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


                         BENCH MARK STAMPING:  3063 E 1978
                         DESIGNATION:          906 3063 E

MONUMENTATION:           Survey disk                           VM#:        12823
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  MB1565
SETTING CLASSIFICATION:  Concrete walk of boat ramp            OPUS PID:        
LATITUDE:   41° 32.5' N (  41.54097)          LONGITUDE:  81° 38.1' W ( -81.63503)


The bench mark is a disk in the top of the SE end of the concrete walkway of the
SW one of six (6) boat launching ramps, 13.45m (44.13 ft) ENE of the E corner of
the NOS water level gage house, 8.14m (26.71 ft) N of a pay phone, 0.39m (1.28
ft) N of the NE face of the metal bulkhead of the SW boat ramp.  Note  - mark
was previously covered up by a new concrete cap on walkway to raise walkway due
to high water, due to low water conditions the cap was removed.  High water
conditions in the future may result in another cap being poured to bring walkway
height back up.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  9

                                                                                
Station ID: 9063063                         PUBLICATION DATE:  08/11/2017
Name:       CLEVELAND, LAKE ERIE                              
            OH
NOAA Chart: 14839                           Latitude:   41° 32.5' N (  41.54086)
USGS Quad:                                  Longitude:  81° 38.1' W ( -81.63547)


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


                         BENCH MARK STAMPING:  E 322 1981
                         DESIGNATION:          E 322

MONUMENTATION:           Bench Mark disk                       VM#:        12826
AGENCY:                  National Geodetic Survey              IDB PID#:  MB1561
SETTING CLASSIFICATION:  Abutment                              OPUS PID:        
LATITUDE:   41° 32.0' N (  41.53397)          LONGITUDE:  81° 38.3' W ( -81.63869)


The bench mark is a disk on the N end of the E abutment of the Conrail railroad
overpass bridge, on E 72nd Street near Gordon Park, set vertically in the W face
of the abutment, 14.06m (46.13 ft) SE of the center of a manhole cover on top of
a street drain along the northbound lane of E 72nd Street, 5.72m (18.77 ft) E of
the center line of the N-bound lane of E 72nd Street, 0.51m (1.67 ft) S of the N
end of the abutment and 1.00m (3.28 ft) above the sidewalk.



                         BENCH MARK STAMPING:  906 3063 H 2003
                         DESIGNATION:          906 3063 H

MONUMENTATION:           Flange-encased Rod                    VM#:        18298
AGENCY:                  National Geodetic Survey              IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   41° 32.4' N (  41.54022)          LONGITUDE:  81° 38.1' W ( -81.63481)


The bench mark is a stainless steel rod along the S fence line that separates
the state park and a white bricked boat house, 62.40m (204.72 ft) SSE from the
SW corner of the NOS water level gauging house, 27.75m (91.04 ft) W from the SE
corner of the fence post, 24.30m (79.72 ft) SW from the center line of the park
entrance street leading to the NOS water level gauging house and boat ramps,
3.75m (12.30 ft) NE of the fence line that separates the S edge of the state
park and boat house, 3.72m (12.20 ft) NE of a witness post, mark is encased in a
5 inch PVC sleeve with an access cover set in a concrete kick block.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  9

                                                                                
Station ID: 9063063                         PUBLICATION DATE:  08/11/2017
Name:       CLEVELAND, LAKE ERIE                              
            OH
NOAA Chart: 14839                           Latitude:   41° 32.5' N (  41.54086)
USGS Quad:                                  Longitude:  81° 38.1' W ( -81.63547)


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


                         BENCH MARK STAMPING:  F 322 1981
                         DESIGNATION:          F 322

MONUMENTATION:           Metal Rod                             VM#:        21215
AGENCY:                  National Geodetic Survey              IDB PID#:  MB1568
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   41° 32.5' N (  41.54111)          LONGITUDE:  81° 37.5' W ( -81.62527)


The bench mark is a stainless steel rod 17.80m (58.4 ft) SSE of a light pole
with a stop sign numberd 'KWP 11-97 PA.3', 14.33m (47.0 ft) NW of the center
line of hte boulevard, 7.81m (25.6 ft) WNW of a fire hydrant, 0.86m (2.8 ft) SW
of the SW fence corner.





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  8 of  9

                                                                                
Station ID: 9063063                         PUBLICATION DATE:  08/11/2017
Name:       CLEVELAND, LAKE ERIE                              
            OH
NOAA Chart: 14839                           Latitude:   41° 32.5' N (  41.54086)
USGS Quad:                                  Longitude:  81° 38.1' W ( -81.63547)


                             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  9 of  9

                                                                                
Station ID: 9063063                         PUBLICATION DATE:  08/11/2017
Name:       CLEVELAND, LAKE ERIE                              
            OH
NOAA Chart: 14839                           Latitude:   41° 32.5' N (  41.54086)
USGS Quad:                                  Longitude:  81° 38.1' W ( -81.63547)


                             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/.