Estuary research on the Otway coast

The estuaries found along the coastline of the Corangamite region are fascinating and dynamic environments. Of the 23 estuaries in our region, the Barwon River estuary is the only one that is permanently open. All the rest are classed as "intermittently open/closed estuaries” (IOCE), which means they sometimes close to the ocean.

Artificial estuary openings

Corangamite CMA regulates artificial openings of estuaries throughout the region. An artificial opening most commonly occurs when the estuary mouth is closed off from the ocean due to a berm (a sandbar) that has naturally built up, meaning the river water cannot empty into the ocean. When heavy rain is forecast the decision is made whether or not to remove the berm to allow the excess water to flow into the ocean, avoiding the inundation of assets on adjacent land.

Estuary research

From January to May 2019, University of Melbourne scientists, led by Dr Sarah McSweeney, and the Australian Rivers Institute have been collecting field data during artificial estuary openings to answer questions such as:

• How does the freshwater and saltwater drain out when the estuary mouth is opened?
• Is the rate of drainage affected by management actions?
• And how do changes at the estuary mouth affect the conditions upstream?

Researchers use special equipment to monitor the changes in the estuary mouth and water quality upstream, from the start of the artificial estuary opening up until the lagoon stops draining.

In collaboration with Corangamite CMA staff and EstuaryWatch volunteers, research will initially focus on the Curdies River and the Gellibrand River. All of the Corangamite estuaries will be eventually monitored as part of the study, including the Aire River, Barham River, Kennett River, Wye River, Erskine River, Painkalac River, Anglesea River, Spring Creek and Thompson Creek.

How can I be involved?

If you would like to join EstuaryWatch, please contact Deirdre Murphy phone  0418 145 818 or email deirdre.murphy@ccma.vic.gov.au.