Halifax shipyard is looking to expand. The type-26 is a much larger vessel then was envisioned when the CSC project began, and as a result it needs more space. the size of the ship will require moving the paint booths outside, and the installation of a synchrolift.

to do this, the yard has applied to infill a portion of the harbour. From the Impact assessment release:

Irving Shipbuilding (ISI) is proposing to expand and modify site and facilities at the Halifax Shipyard. The Halifax Shipyard site expansion will include dredging, marine structures and rock infill behind the structure creating approximately 13 acres of additional yard space. The newly expanded area will not extend farther into the channel than the limits of the floating dry dock that was previously located at Halifax Shipyard

The shipyard owns a water lot, and that is likely what they are looking to infill. That lot is marked in black and is not an overly usable portion of the harbour. you can also see the pre-expansion shoreline marked.

At least one outlet is commenting that proposed infill will destroy the last remaining physical evidence of the Halifax explosion. Many people believe there is a large crater on the sea floor where the Mont Blanc exploded, however there is not.

Several years ago NRCAN produced a website looking at the harbour. part of that site, was a section devoted to Busting harbour Myths, including the fact that there is no crater from the explosion, which occurred at the point marked by the X in the survey image above.