August 27, 2021 | Circular No. 11314

Dear Member,

The St. Lawrence Seaway have advised they will be dredging sections of the navigable channel near Montreal / St. Lambert / Cote Ste. Catherine, which will impact navigation.  The dredging project is expected to start September 15th and run daily for 16-19 days with intermittent navigation stoppages per day.

Dredging in this sector has not been done for nearly a decade and has been deferred in recent years due to the high water flows.  The higher currents created considerable sediment build up whereby dredging has become necessary to ensure maximum drafts can be maintained.  The dredging must be done in the navigation season as higher water flows (unsafe for navigation) and potential ice conditions (Icebreaker support) could render the dredging project unfeasible.  See dredging project overview for more details regarding the specific areas to be dredged.

Impacts on Navigation

It is expected that traffic will be stopped for a maximum of 3 x 4 hour slots per day and the Seaway will endeavor to identify those periods with the least impact to traffic.  Similar to the outages during the construction of the Champlain Bridge, traffic will be monitored closely and the Seaway will determine the optimum 4 hour window to stop traffic and commence dredging.  These windows will be dynamic rather that fixed to minimize the impact to navigation.

The GLPA advise they will work closely with the Seaway regarding the movement of traffic.  Pilot detention will be managed on a case by case basis where the preference will be to keep a pilot on board if less than 4 hours, otherwise the GLPA may consider to remove the pilot from the vessel.  GLPA advise that if a pilot is removed there will be no need of the 12 hour notice and they will assign pilots as needed on short notice.


The Seaway intend to advise users more than 4 hours and confirm within 1 hour before the start of each closure.  The Seaway will provide vessel names impacted and highlight the last vessel to pass before each stoppage.  When navigation resumes, the Seaway will also advise the time of the next predicted closure.

The Seaway will communicate via their “Major Delay” distribution. While the Federation will attempt to relay the outages in real time, we strongly suggest for you to request to be added to their distribution, if not already receiving Seaway delay notices.  A message can be sent to Shari Grady ( to be added to their list.

Please advise any questions or concerns to the undersigned.

Chad Allen

Director, Marine Operations