Long Oral Presentation 11th Australian Stream Management Conference 2024

Hydrological Restoration of the Critically Endangered Fleurieu Peninsula Swamps Ecological Community (#57)

Ben Taylor 1
  1. Nature Glenelg Trust, PROSPECT, SA, Australia

The Fleurieu Peninsula Swamps ecological community is listed as critically endangered under the Federal EPBC Act 1999. This community has a very restricted geographic range and is highly biodiverse. Due to their fertility, Fleurieu Swamps were historically targeted for conversion to agriculture, involving clearance of vegetation and the excavation of drains to prevent inundation and reduce waterlogging. Recovery efforts over several decades focused on fencing to exclude livestock, weed control and, to a lesser degree, prescribed burning. More recently, Nature Glenelg Trust, in collaboration with landholders and other partners, has added hydrological restoration to the suite of recovery actions.

Many Fleurieu Swamps, including some of the most intact remnants, show clear evidence of historical drainage and its ongoing ecological impacts. On-ground works to address these legacy impacts include the placement of blocking structures within drains and complete drain backfilling. Works aim to reverse the drawdown of groundwater and reinstate natural patterns of surface inundation and flow. Dramatic and rapid improvements to swamp vegetation have been observed in important sites such as Glenshera Swamp (Stipiturus Conservation Park) as well as measurable improvements to hydrology.

Challenges to this work have included the need to balance remnant values with the short-term disturbance required for on-ground works, the erosion of works in extreme rainfall events, the difficulty of earthworks in waterlogged ground and, in some cases, uncertainty of how restoration fits within water allocation planning.

With artificial drains ubiquitous in the landscape there remains considerable scope to expand hydrological restoration throughout the geographic range of Fleurieu Swamps. Climate change reinforces the urgency of the task. The main constraints are shared by most other conservation initiatives; funding for works and ongoing monitoring and the willingness of private landholders to forego primary production for conservation outcomes. 

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