Channel deepening 10% complete

The channel-deepening project in Victoria's Port Phillip Bay was about 10% complete, the Port of Melbourne Corporation said, towards the end of March.

Since the Queen of the Netherlands began dredging on February 8, she had removed 2.99m m of material from the bay.

The vessel was due to dredge clay in the Port of Melbourne Channel until April 4, and would then start work at the entrance to the bay, a more sensitive and controversial aspect of the project.

Dredging in the Port of Melbourne Channel would see the construction of an underwater containment facility – a bund – to hold up to 2m m of silt from the mouth of the Yarra River.

The port corporation said 1.1m m had been removed from the Port of Melbourne Channel since March 1.

Chief executive Stephen Bradford pointed out that only 100,000m of silt had been dredged between days 41 and 48 of the channel-deepening project. This compares with 925,000m that had been removed from the north channel a week earlier, between days 34 to 41.

“That (1.1m m) is not a great deal greater than this time last week,” Bradford said. That was because the dredger was pombaa levelling, in which the vessel constructs gradients and shapes out the channel. “Once we get down to the desired level, the amount of productivity drops because the bulk material has been removed,” Bradford said.

He said that the Queen would travel along the south channel once a day to dredge a complete load of clean sand. “That (dredging the clean sand) is part of cleaning the hopper and she dredges clay the rest of the day,” he said. “The clean sand is then placed in the bund.”

The Queen wa s scheduled to move into Port Phillip Heads on April 4, depending on the outcome of the court case between PoMC and Blue Wedges. The PoMC won that case on March 28.

The port corporation said that another dredger, Goomai , had arrived in the port. It was scheduled to start finer dredging around the berth in early April, working closer to the berth areas that the Queen could not access.

Between mid-April and Anzac Day, the Cornelis Zonen would arrive in Port Phillip Bay and continue working on the bund, while the Queen dredged in Port Phillip Heads. “The Queen of the Netherlands should be doing the heads until about September,” Bradford said.

The corporation's environment director Jeff Bazelmans, said that while the Queen was working in Port Phillip Heads, there would be a weekly clean ip to minimise the amount of loose material left behind by the dredger and pushed around by storms and currents.

“Clean-up will occur every seven days, or when there is a weather forecast of a storm, the Queen will switch into clean-up mode, which is basically a non-cutting action. It's like a Hoover.”