U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 9076060 PUBLICATION DATE: 08/11/2017 Name: U.S. SLIP, ST. MARYS RIVER MI NOAA Chart: 14884 Latitude: 46° 30.0' N ( 46.50080) USGS Quad: Longitude: 84° 20.4' W ( -84.34036) TO REACH THE NOS GAUGE HOUSE, IN SAULT STE MARIE, CHIPPEWA COUNTY, MICHIGAN, FROM THE INTERSECTION OF ASHMUN ST AND PORTAGE AVE, PROCEED SOUTH ON PORTAGE FOR 0.2 MILES (0.3 KM) TO THE INTERSECTION WITH BRADY ST, THEN PROCEED NORTH ON BRADY ST FOR 0.07 MILES (0.11KM) TO THE INTERSECTION WITH WATER ST, THEN PROCEED EAST ON WATER STREET FOR 0.25 MILES (0.40 KM) TO THE INTERSECTION WITH LEGION DR, THEN PROCEED NORTH ON LEGION DR FOR 0.10 MILES (0.16 KM) TO THE CORPS OF ENGINEERS BOATYARD ON THE NORTH SIDE OF LEGION DR, THE GAUGING STATION IS LOCATED INSIDE THE CAGED AREA OF THE NORTHWEST CORNER OF THE COE BOATHOUSE. G R E A T L A K E S B E N C H M A R K S PRIMARY BENCH MARK STAMPING: C 293 1983 DESIGNATION: C 293 MONUMENTATION: Flange-encased Rod VM#: 13171 AGENCY: National Geodetic Survey IDB PID#: RJ0613 SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID: LATITUDE: 46° 30.0' N ( 46.50075) LONGITUDE: 84° 20.6' W ( -84.34297) The bench mark is a flange-encased rod 29.57 meters (97.01 ft) ENE of the SE corner of the concrete foundation of the General Lewis Cass rock monument, 27.0 meters (88.6 ft) NNE of the North curb of Water Street, 4.7 meters (15.4 ft) NNW of the NE corner of the Saint Mary's fall monument, 4.6 meters (15.1 ft) NNE of the NW corner of monument, being a deep rod set in a 5 inch sleeve level with grade.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 9076060 PUBLICATION DATE: 08/11/2017 Name: U.S. SLIP, ST. MARYS RIVER MI NOAA Chart: 14884 Latitude: 46° 30.0' N ( 46.50080) USGS Quad: Longitude: 84° 20.4' W ( -84.34036) G R E A T L A K E S B E N C H M A R K S BENCH MARK STAMPING: DESIGNATION: 907 6060 BOATHOUSE MONUMENTATION: See descriptive text VM#: 13172 AGENCY: IDB PID#: RJ0009 SETTING CLASSIFICATION: WALL OPUS PID: LATITUDE: 46° 30.0' N ( 46.50081) LONGITUDE: 84° 20.4' W ( -84.34036) The bench mark is a high point on a one inch brass plate at the end of an iron arm, located inside and near center of a 0.31m (1.02 ft) diameter iron well with metal cover, 4.6m (15.1 ft) NE of the NW corner of monument, 1.5 meters (4.9 ft) South of North wall of building, and 0.37 meters (1.21 ft) East of West wall of monument. BENCH MARK STAMPING: DESIGNATION: 907 6060 BOATHOUSE W MONUMENTATION: Chiseled Square VM#: 13173 AGENCY: IDB PID#: RJ0010 SETTING CLASSIFICATION: WATER TABLE OPUS PID: LATITUDE: 46° 30.0' N ( 46.50081) LONGITUDE: 84° 20.4' W ( -84.34036) The bench mark is a 1-inch chiseled square cut in top of the SW corner of the concrete water table, near the North side of a double door which leads to water level gauge inside boathouse, 4.22m (13.85 ft) NE of a flagpole, 3.1m (10.2 ft) South of NW corner of boathouse, 1.2m (3.9 ft) North of the center of double doors (West entrance to boathouse).
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 9076060 PUBLICATION DATE: 08/11/2017 Name: U.S. SLIP, ST. MARYS RIVER MI NOAA Chart: 14884 Latitude: 46° 30.0' N ( 46.50080) USGS Quad: Longitude: 84° 20.4' W ( -84.34036) G R E A T L A K E S B E N C H M A R K S BENCH MARK STAMPING: DESIGNATION: 907 6060 WAREHOUSE N MONUMENTATION: Bolt VM#: 13176 AGENCY: IDB PID#: RJ0013 SETTING CLASSIFICATION: CONCRETE SILL OPUS PID: LATITUDE: 46° 30.1' N ( 46.50203) LONGITUDE: 84° 20.7' W ( -84.34442) The bench mark is a bolt below the locks, on the canal side (channel side) of the U.S. Corps of Engineers warehouse building on the east side of the middle entrance to building, 3.02 m (9.91 ft) east of the west side of concrete entrance, 0.37 m (1.21 ft) south of a steel post on west side of entranceway, 10.67 cm west of the east side of concrete entrance, a brass bolt set in concrete door sill at the NE corner of sill. BENCH MARK STAMPING: PT DESIGNATION: 907 6060 PT MONUMENTATION: Survey disk VM#: 13177 AGENCY: US Engineers IDB PID#: RJ0014 SETTING CLASSIFICATION: Approach seawall to lock OPUS PID: LATITUDE: 46° 30.1' N ( 46.50219) LONGITUDE: 84° 20.7' W ( -84.34478) The bench mark is is a survey disk below the locks, on South seawall of approach to the Mac Arthur Lock, on an extended line and North of the West face of the U.S. Corps of Engineers warehouse building, 11.00m (36.09 ft) WNW of the last entrance way on the North face of the warehouse, near the NW corner, 8.80m (28.87 ft) North of the NW corner of the COE warehouse, 0.58m (1.90 ft) South of North edge of seawall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 9076060 PUBLICATION DATE: 08/11/2017 Name: U.S. SLIP, ST. MARYS RIVER MI NOAA Chart: 14884 Latitude: 46° 30.0' N ( 46.50080) USGS Quad: Longitude: 84° 20.4' W ( -84.34036) G R E A T L A K E S B E N C H M A R K S BENCH MARK STAMPING: PC DESIGNATION: 907 6060 PC MONUMENTATION: Survey disk VM#: 13178 AGENCY: US Engineers IDB PID#: RJ0015 SETTING CLASSIFICATION: Approach seawall to lock OPUS PID: LATITUDE: 46° 30.1' N ( 46.50233) LONGITUDE: 84° 20.8' W ( -84.34736) The bench mark is is a survey disk just below the Soo Lock, set in top of the S seawall of approach to Mac Arthur Lock, and about 97.6m (320.2 ft) East of extended line of East face of U.S. Corps of Engineers administration building, 31.7m (104.0 ft) NE of light pole 216, 7.88m (25.85 ft) North of the security fence, 0.6m (2.0 ft) South of North edge of seawall. BENCH MARK STAMPING: 10 DESIGNATION: 10 MONUMENTATION: Survey disk VM#: 18416 AGENCY: IDB PID#: AE8000 SETTING CLASSIFICATION: CONCRETE BULKHEAD OPUS PID: LATITUDE: 46° 30.1' N ( 46.50178) LONGITUDE: 84° 20.5' W ( -84.34206) The bench mark is a survey disk set flush in the concrete bulkhead at the East end of the locks, 18.48 m (60.63 ft) NW of the boat basin's NW inside corner, 7.29 m (23.92 ft) NNE of the NE corner of a concrete building, 1.07 m (3.51 ft) South of the face of the bulkhead. 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 5 of 6 Station ID: 9076060 PUBLICATION DATE: 08/11/2017 Name: U.S. SLIP, ST. MARYS RIVER MI NOAA Chart: 14884 Latitude: 46° 30.0' N ( 46.50080) USGS Quad: Longitude: 84° 20.4' W ( -84.34036) 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 6 of 6 Station ID: 9076060 PUBLICATION DATE: 08/11/2017 Name: U.S. SLIP, ST. MARYS RIVER MI NOAA Chart: 14884 Latitude: 46° 30.0' N ( 46.50080) USGS Quad: Longitude: 84° 20.4' W ( -84.34036) 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/.