Chapman River opening delayed for safety, now set to proceed
The planned artificial opening of Chapman River into Antechamber Bay, managed by the Kangaroo Island Council, was delayed this year due to extensive water testing prompted by the harmful algal bloom affecting waterways across South Australia.
The Kangaroo Island Landscape Board’s Water Officer, Phoebe Edwards, has spent recent weeks closely monitoring water quality in the estuary surrounding Chapman River. Testing focused on ensuring that dissolved oxygen levels in the system were adequate to support aquatic life and safe for the river’s eventual opening.
In positive news, native fish species such as Southern Black Bream and mullet have begun spawning in the Chapman River system. Additionally, local shorebirds are currently nesting along the estuary — key indicators that the water quality has stabilised and is safe for the river opening to proceed.
“The presence of spawning fish and nesting shorebirds is an encouraging sign that the system is recovering well,” said Phoebe Edwards.
“We thank the community for their patience while we carried out the necessary assessments to protect these valuable ecosystems.”
Estuary closure is a natural—and indeed vital—process for the ecological health of our estuaries and waterways, with natural openings being the preferred outcome.
However, when prolonged dry conditions occur in the catchment at the same time as significant ocean swells, a substantial sandbar may form at the estuary mouth. This kind of sandbar often has a very low chance of reopening on its own. This can lead to flooding of riparian - or creek line - vegetation and infrastructure for extended periods of time, and the depletion of dissolved oxygen in the system if an artificial opening is not undertaken.
Kangaroo Island Mayor Michael Pengilly said the Kangaroo Island Council has regularly opened the river, which is also done by locals, as required.
“The Kangaroo Island Council began work on the artificial river opening at Antechamber Bay today and will continue to monitor progress,” Michael Pengilly said.
The Kangaroo Island Landscape Board extends its thanks to Antechamber Bay residents and visitors for their understanding and support during this critical monitoring period.
