In many cases this will be a function of the Basemap Registration, e.g., if the data is tied to TRIM it is mapped to NAD83. This is to be specified if the data includes a value for elevation. Only one option is allowed. CVD28 - Canadian Vertical Datum 1928, a reference surface used as the basis of elevation, depth and tide measurements. All vertical measurements are based on mean sea level as defined by this datum.
Choices are as follows.
British Columbia spans UTM zones 7-11, each zone is 6 degrees of longitude in width, the central meridian being the longitude at the midpoint of the 6 degree span. Rectangular coordinates are metric with Easting values offset by 500,000 metres. This projection pre-defines specific parameters for use with the Albers Equal Area Conic projection. Use of the National Transformation Grid Version 2.0 is recommended for all datum conversions. This will be significant in areas of the northeast of the Province where the required accuracy is 20 metres or less.