Inundation and Sea Level Rise Impacts and Adaptation for South Arm Secondary Road, Hobart, Tasmania

Client: Pitt&Sherry
Year: 2008
Project Reference: 08005

This investigation was undertaken to analyse the effects of inundation and sea level rise for a stretch of the South Arm Secondary Road near South Arm, Hobart. The client for the project was Pitt and Sherry (P&S), and the Water Research Laboratory’s investigation formed a component of their submission to the Roads and Traffic Division of the Department of Infrastructure, Energy, and Resources (DIER), regarding the issue of inundation of the road.

South Arm Secondary Road stretches from Rokeby to Opossum Bay, and provides the only road access to the townships on the South Arm Peninsula which have a population of approximately 1000 people. Generally, the road is set back from the edge of Ralphs Bay by 10 - 20 m, and is at an elevation of typically 1.5 m AHD. On a number of occasions in recent times (at least in August 2007 and March 2008) the “Neck” section of road has been inundated when low pressure weather patterns coincided with high tides.

In undertaking this inundation investigation, a range of coastal processes required consideration when assessing the extent and recurrence of inundation, these being: