ABSTRACT
This chapter presents a resume of areas of known instability, a description of the nature and reasons for sliding and relationship to geology and topography, the engineering implications and means of stabilization. It discusses zones of extensive instability in Sydney in areas underlain by the Wianamatta Group. The major slump and slump-flow landslides occur in the western and south western areas of Sydney. Creep landslides cover areas up to 500m by 200m and are important since relatively minor disturbance by earthworks and other urban development can initiate more rapid landsliding. Slump and slump-flow landsliding is also potentially disruptive but because it is more obvious, is less likely to be overlooked in suburban development. These landslides most commonly occur in re-entrants between spurs, and predominantly on south or south east facing slopes. It is significant that the slump-slump flow landslides occur in areas of considerable topographic relief.
