The channels have been progressively enlarged and developed over a period of 150 years, the most recent change being a major deepening project carried out in 1996–97.
In 2015 the VRCA called for tenders to undertake localised dredging adjacent to Refinery Pier No.4 Berth, at the northern end of the Corio Channel with the purposes of reducing operational risks arising from the increasing size of vessels gaining access to the berth, and to facilitate the future development of Lascelles Wharf No.4 berth.
In September 2015 Heron mobilised the Machiavelli, three tugs, a survey vessel and two 1,200m3 split hopper barges to Geelong from Webb Dock in Melbourne following the successful completion of the Port Capacity Project’s Stage 1 works.
The scope of works involved the removal 265,000m3 of silt and clay from an area adjacent to Refinery Pier No.4. This material was placed precisely within an existing designated dredge material ground (DMG) in Port Phillip Bay.
The DMG was sub divided into barge size cell to increase the accuracy of the placement. With dredging complete, the area was swept with sweep bar and tug.
Additional works also included rock trials area Wilsons Spit and the extensive sweeping of the Geelong shipping channel to remediate areas of siltation throughout the channel.
Following the completion of the Geelong works the Machiavelli returned to the Port Capacity Project at Webb Dock.