Key point

  • When the risk from natural hazard risk exceeds the tolerable risk of damage to property and human life, a council can voluntarily acquire property to mitigate intolerable risks.

Parts of the Wollongong local government area are subject to significant flood hazarding that can lead to extensive property damage. Flood events in the 1980s and 1990s caused considerable losses.

Much of this damage and loss occurred where development was within floodplain extents. Approval for these developments is unlikely to be granted today given our greater understanding of flood risks and extent.

Voluntary acquisition program

To reduce the risk of property damage and the potential risk to life from inappropriately sited development, Wollongong City Council undertook a voluntary acquisition program for affected properties, purchasing the privately-owned land.

Since the major floods of the 1980s and 1990s, the council has acquired properties in the worst flood-affected areas. Properties were identified for voluntary purchase immediately or shortly after a flood event, or they were identified in a flood risk management plan. These types of acquisition purchases are commonly completed with supporting funds from the NSW Government.

The council noted, ‘whilst most engineered flood mitigation options would have relevantly high maintenance costs and would need to be upgraded or rebuilt at the end of their useful life, it is not the case under voluntary purchase. The houses voluntarily acquired by [the] council are demolished and the sites are generally rehabilitated to open grass with an associated mowing schedule. The total long-term cost of voluntary purchase is found to be generally lower than engineered flood mitigation works’.

Acquired properties

To date, 70 properties have been voluntarily acquired by the council across the Wollongong local government area since 1984. These have been in the catchments of:

  • Allans Creek
  • Collins Creek
  • Fairy and Cabbage Tree Creek
  • Hewitts Creek
  • Minnegang Creek
  • Mullet Creek
  • Towradgi Creek.

This case study shows how a council provided an option to landowners in areas where the risk from flood hazards was intolerable and planned for a more sustainable use of the land.