Catchments of Port Phillip and Western Port (including Port Phillip Bay [Western Shoreline] and Bellarine Peninsula Ramsar wetland and Western Port Ramsar wetland)


On 21 September 2015, responsibility for water policy and resources was transferred to the Department of Agriculture and Water Resources - Administrative Arrangement Order made on 21 September 2015.

This website will be updated to reflect these changes.

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About the catchment

The Port Phillip and Western Port region is an area of 12 000 km2, which comprises approx 8000 km of rivers and creeks.

Much of this area is occupied by the city of Melbourne and its peri-urban surrounds, and includes a population of 4.3 million people.

The catchment comprises the whole of the Bunyip River, Yarra River, Maribyrnong River and Werribee River drainage basins, plus the catchments of the Little River system, waterways of the Bellarine Peninsula that discharge to Port Phillip Bay and Swan Bay, and the Bass River system of South Gippsland.

Reedy Lake and Lake Connewarre, as well as their catchments, are not included in this water quality hotspot.

Values to be protected

Port Phillip Bay and Westernport contain a mixture of unique and complex ecosystems. The catchments in the Port Phillip and Westernport Region have significant environmental, social and economic values. It includes a population of 4.3 million people. The bays and beaches as well as the 8000 kilometres of rivers and creeks are vitally important natural assets to the community.

Agricultural productivity and commercial and recreational fisheries are important activities of the catchment.

Areas of important wetland habitat in both Bays are listed as wetlands of international significance (Ramsar wetlands) and include areas of Victoria's most depleted wetland habitats. They support threatened species and large numbers of waterbirds many of which are protected under migratory bird agreements.

Ramsar sites

Water quality issues

The health of Melbourne's bays and waterways can be directly linked to human activities. As the population of Melbourne and surrounding areas continues to grow, the difficulty of protecting water quality and biodiversity increases. Sediment and nutrients from urban, agricultural and industrial stormwater and wastewater discharges threaten the health of Port Phillip Bay and Western Port including a risk to seagrasses which play an important role in the Bay ecosystems. Other threats include: altered water regime; dredging; oil spills; marine invasive species; habitat disturbance and loss; and coastal erosion.

Key water quality improvement projects

Key stakeholders / agencies

  • EPA Victoria
  • Melbourne Water
  • Department Primary Industries
  • Department of Sustainability and Environment
  • Catchment Management Authority