Wetlands Australia 31: Restoring the Wannon River floodplain to buffer against climate change

Author: Mark Bachmann (Nature Glenelg Trust)

A large proportion of the Upper Wannon River floodplain surrounding Walker Swamp was drained from the 1950s for agriculture and later converted to a Tasmanian Blue Gum plantation forest. This major new restoration project is returning the site to its former glory.

The Upper Wannon River floodplain is adjacent to the Grampions National Park in western Victoria. Nature Glenelg Trust (NGT) has been progressively working to restore the wetlands of the floodplain across public and private land, with successful permanent works now completed at Brady Swamp and Gooseneck Swamp in the Grampians National Park.

Stage 1 (northern - yellow outline) and Stage 2 (southern - white outline) of the new Walker Swamp Restoration Reserve. The minimum area of drained wetlands on the floodplain to be restored is shaded blue, and major artificial drains are marked red. Photo: Nature Glenelg Trust

A recently awarded Victorian Government Climate Change Innovation Grant (via DELWP) is funding major on-ground works over the next two years that will see Walker Swamp transformed into a community demonstration site for sustainable floodplain restoration and management; by removing the plantations and reversing artificial drainage across the more than 440 hectares of land now owned by Nature Glenelg Trust.

These activities will restore natural river floodplain function, recreating wetland habitats for threatened and iconic species, like the Growling Grass Frog and Brolga. The works will also buffer the site against climate change, by retaining significantly more water in the landscape in the future.

This will:

• reduce the likelihood of serious downstream flooding impacts during episodic rainfall events
• restore and recover currently compromised ecological function
• increase soil carbon sequestration rates and trigger spontaneous vegetation recovery and
• literally make the most of every drop of water that is available in the future from the catchment, by enabling it to fill and be retained in the restored wetlands rather than be artificially drained downstream.

A minor restoration trial on the deepest part of Walker Swamp has been in place since 2014, giving a taste of what is to come, but the major on-ground works as a result of NGT securing the site – including the backfilling of over 20 kilometres of artificial drains on the floodplain – are due to commence in autumn 2019. So we have an exciting year ahead!

The project is being delivered by NGT in partnership with the Glenelg Hopkins CMA and the Hamilton Field Naturalists Club, with grant funding support from the Victorian Government, and support from the wider community.

Impact of the trial restoration structure and early works in 2018 at the new Walker Swamp Restoration Reserve. Photo: Nature Glenelg Trust

Further information

Please visit Nature Glenelg Trust for updates.