What is an Estuary?

An estuary is the area where a river meets the sea. Estuaries are unique and dynamic environments that include some of the most complex ecosystems on earth, and the Corangamite region has more estuaries than anywhere else in Victoria.

Estuaries are a great place to spend time swimming, walking, canoeing or having a picnic. Importantly, they also act as buffers to protect shorelines from erosion, flooding and provide essential food and habitat for birds, fish and other wildlife.

FAQ’s About Estuaries

Why do estuaries open and close?

Many of Victoria’s estuaries open and close as part of a natural process, due to variations in river flows and ocean forces. Natural variations in an estuary is an important feature of these dynamic ecosystems, as it supports the different life and reproductive cycles of a wide range of plants and animals.

Why are estuaries artificially opened?

Sometimes, estuaries are artificially opened to manage the risk of flooding to built infrastructure and agriculture land. Permit holders can request to artificially open an estuary if they deem it necessary. Considerations include inundation of human assets such as properties, roads, bridges, campgrounds and playgrounds.

Who can artificially open an estuary?

Only permit holders can be authorised to artificially open an estuary. Anyone who opens an estuary without a permit can be fined up to $33,000 and/or imprisoned for up to 10 years under the Land Act 1958Water Act 1989Catchment and Land Protection Act 1994Fisheries Act 1995 and Marine and Coastal Act 2018.

What is the process behind artificially opening an estuary?

Once the decision has been made to open an estuary, the Corangamite CMA is notified and undertakes a risk-based assessment to inform the permit holder when and how the estuary can be opened. Environmental, social and economic factors are considered.

The permit holder is responsible for conducting water quality testing pre-opening and the physical removal of the sand berm (sand bar) to allow the estuarine water to flow into the ocean.

Will the Corangamite CMA artificially open an estuary?

No. Estuaries are artificially opened due to inundation of human assets. The Corangamite CMA do not intervene in natural processes, so do not open or close estuaries.

Where can I find more information about the estuaries in our region?

You can find more information about the estuaries in the Corangamite region, such as, studies, reports and estuary management plans in the Publications and Knowledge Base section of the website.

The fact sheet below provides information on how estuaries function during periods of low river flow.

Fact sheet: Should an estuary be opened or closed? 

Help Monitor Your Local Estuary

  • Join EstuaryWatch, a community-based citizen science program which monitors the condition of 11 estuaries in the Corangamite region.
  • Snap a photo on a Fluker Post. Have you seen a wooden post with a sloped top and wondered what it was for? This is a Fluker Post, which helps monitor changes in the environment. Simple place your phone or camera on top of the Fluker Post, take a photo and upload it to the Fluker Post app: http://www.flukerpost.com/