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Beaches in Port Phillip Bay

Beaches in Port Phillip Bay



The beaches of Port Phillip Bay are part of Victoria’s way of life and a focus of community interest.

Beaches are not static. Like other shoreline areas in Victoria and around the World, the Bay’s beaches are continuing to adjust to the rising sea levels of the recent geological past. Both erosion and deposition are features of this adjustment.

Beaches also continue to adjust, reflecting conditions that vary from day to day and year to year. In the Bay, sand that forms the beaches is often in near constant movement, driven by the effects of wind and tides. Where the supply of sand to a beach is reduced the beach will erode, and where the supply is increased the beach will grow.

In Victoria, erosion is often conspicuous and severe following major storms and it may take some time following a storm to see the full effect. Erosive forces can be amplified by a combination of strong winds, the effects of water being pushed into the Bay by storms in the Southern Ocean and occasional higher than normal tidal levels when air pressure is low.

Human activities also affect beaches. Adding sand to beaches through renourishment programs replaces the sand lost by erosion. We have also learnt from experience that some actions can accelerate erosion by disrupting the supply of sand or exacerbating the erosive effects of storms.
Beach erosion at Portsea was not due to channel deepening.
The effects of dredging on erosion were considered as part of the Supplementary Environment Effects Statement for the Channel Deepening Project.


The Office has considered all available monitoring data on tides, waves, currents and bathymetry of the Great Sands region in the south of the Bay before and after the dredging of the Entrance and South Channel. All evidence is consistent with the limited effects that were predicted, and these limited effects are not considered sufficient to cause the beach erosion seen in the Bay.


Relevant reports




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