ABSTRACT
Landslide investigations undertaken by the Geotechnical Engineering Office have shown that inadequate surface drainage provisions can be a key contributory factor in causing landslides and washout failures in Hong Kong. This chapter presents the findings of a review of the landslide hazard scenarios associated with potential surface water drainage problems, together with the design and detailing aspects of surface drainage provisions on slopes. The problems of uncontrolled overland flow in triggering landslides or major washouts have been demonstrated by a number of significant landslide incidents. Given the setting of a dense urban development on steep hilly terrain, the potential landslide hazards associated with inadequate surface drainage provisions may result in major social impact and economic losses. The subsequent landslide investigation revealed that the washouts were mainly caused by inadequate design and poor detailing of the surface drainage provisions.
