The Bay at the centre of Boon Wurrung/ Bunurong, Wurundjeri and Wathaurong/ Wadawurrung Country is called Nairm or Nerm (Narrm Narrm). The Kulin people have thousand-year-old stories and knowledge of how the Bay changed over many generations. Archaeological excavations from around Nairm have found evidence that people lived in the area from around 32,000 years ago. Boon Wurrung and Wurundjeri people each have stories about a great flood that caused the Bay to fill during a time of chaos where Bundjil stopped the water from rising. Before this flood occurred, the area where the Bay is now was a dry, grassy plain that was good hunting for emu and kangaroo. The Yarra, Barwon and Werribee Rivers flowed into a small lake, and land reached Tasmania via the Bassian plain during the ice age.

In 2011, a Melbourne University study by Dr. Guy Holdgate showed that 1000 years ago, the Bay was dry land and the Birrarung (Yarra River) and Werribee Rivers ran through it. The study found that the entrance to the Bay was blocked by sand and silt build up, cutting it off from the Bass Strait. The water in the Bay evaporated and was dry, except for a small salty lake in the middle where the rivers ended. The channels made by the rivers can still be found on the sea floor of the Bay. Because the Bay was lower than sea level, when the sand bar blocking the sea was breached less than 1000 years ago, possibly by an earthquake, storms or erosion, it filled very quickly as is told in the stories.

Sources & Further Reading

• Culture Victoria, Aunty Caroline Briggs, Boon Wurrung: The Filling of the Bay – The Time of Chaos

• Museums Victoria, Life in the Victorian Forest, How the Yarra was formed

• The Age, Stephen Cauchi, 10,000-year bay theory doesn't hold water

• ABC Science, Port Phillip Bay once high and dry

• State of Victoria, Aboriginal Country