Earth and Structure Works at the Piccaninnie Ponds Conservation Park.

The Piccaninnie Ponds Conservation Park is located 30 km south east of Mount Gambier near the Victorian border. While parts have been cleared of vegetation and drained, it still hosts more than 50 national and state listed plant and animal species ranging from rare to critically endangered. Several areas are permanently inundated by water from Karst rising springs. This water currently flows directly to the sea through an outlet channel that is understood to have been cut through the coastal dunes in the 1940’s. Prior to this, water moved in an easterly direction behind the dunes and ultimately flowed into the Glenelg River Estuary.

The Department has worked toward the re-establishment of part of the natural wetland areas that previously existed within the conservation park. This work aims to retain more surface water in the original wetland areas, especially the eastern wetland and raise the overall wetland sill level closer to that which existed prior to settlement.

Work was undertaken in 2005 at the existing Piccaninnie Ponds outlet as part of a separate project to construct a new regulator structure and fish passageway to allow water levels in the existing pond system to be raised. These works were successful in this objective and considerable outcomes were achieved in habitat restoration. The proposed new works will build on the 2005 works to further raise water levels and enable flows to be diverted to the east.

These works involve:

• Modifications to the current weir, fish way and levee at the existing outlet to enable a higher water level to be achieved;
• Modifications to parts of the existing Local Government access road to raise it above the proposed wetland level,
• Construction of a new transfer culvert under the road,
• Shaping of the landform to the east of the access road to promote flow and wetland reestablishment,
• Shaping of the landform to form a small levee in the eastern wetland, and
• Undertaking modifications to some Park infrastructure to accommodate the proposed water level.