The City of St. Thomas uses the NAD83 CSRS (v6: 2010) (GRS80) datum, 6 degrees UTM projection (Zone 17, Central Meridian 81° West Longitude) as it's horizontal georeferencing system, and the Canadian Geodetic Vertical Datum 1928 (CGVD28) incorporating the 1978 Southern Ontario Adjustment as it's vertical georeferencing system.
All legal surveys, engineering drawings and plans submitted for development approvals including subdivisions and site plans must be referenced to these datums. This enables the City to efficiently assess, review and integrate the information into its GIS datasets, and ensures information can be more easily exchanged with others.
In support of this georeferencing, the City has installed a network of 27 horizontal control monuments and approximately 120 benchmarks throughout the City.
Location Sketches and Values
Monument and benchmark locations sketches and their associated values are obtained from the appropriate layer on the City's CMAP. Or by downloading
St. Thomas Control Monuments.zip.
To view the location sketch and coordinate value associated with a monument, simply click on the centre of the
monument symbol, not the label. Use the link in the information panel and the location sketch will be generated in a separate window for viewing or printing.
Note that it may be necessary to turn of popup blockers in your browser in order to view the location sketch.