Engineers Australia

Assessment of landslide likelihood in the Pittwater Local Government Area

Patrick MacGregor, Bruce Walker, Robin Fell and Andrew Leventhal

Abstract

The likelihood of landsliding in the Pittwater LGA has been assessed by the compilation of an inventory of landslide events that have occurred in the area over a period of more than 30 years. This inventory indicated that most events were associated with residential development. An indication of the population of slope modification was provided by a survey of several areas selected as representative of the properties within the designated geotechnical risk zone.

Rainfall records for Newport have been used a basis for a review of the relationship between rainfall events and landslide events. The results of this analysis have been combined with the landslide inventory and population survey to provide an assessment of the likelihood of the occurrence of landslides in the Pittwater LGA in the future.