Vertical Control – Water Levels

Terms of Reference

  1. Review existing International Great Lakes Datum (IGLD) and revise as appropriate. Issue informational materials, binational standardization guidance and reports for establishing bench mark elevations in the current IGLD reference frame.
  2. Review and update as necessary vertical crustal and other movement rates between and at water level gauge sites in the Great Lakes-St. Lawrence River System, and report coordinated findings.
  3. Review and coordinate methodologies and technology for establishing water level measurements and connections to the vertical reference frame at water level gauges (permanent, seasonal, temporary) in the Great Lakes-St. Lawrence River System.
  4. Review the permanent Great Lakes-St. Lawrence River System water level gauge network, and recommend relocations, additions or deletions to meet the changing needs of the users.
  5. Review the permanent Global Navigation Satellite Systems (GNSS) based reference station network used for vertical positioning in the Great Lakes-St. Lawrence System. Recommend relocations, additions or deletions to meet the changing needs of the users.
  6. Update and publish the coordinated histories of water level gauge sites in the Great Lakes-St. Lawrence River System.
  7. Review and update the method for determining representative lake-wide average water levels for each of the Great Lakes and Lake St. Clair and coordinate the historical statistics for these representative levels.

Last revised:  2017-09-27