At-risk sites have been identified through document and report review, consultation, preliminary risk assessments and a drive-over exercise. In total, twenty five sites have been recognised as potentially problematic, comprising rock fall, landslide, flooding, coastal erosion and debris flow hazards. The sites are shown on the project map (PDF, 3.31 MB).
Each of the sites has been assessed in terms of its geological stability and/or environmental setting and their contributions to route security with an attempt to prioritise sites in terms of seriousness and urgency. The following ten sites are considered the most problematic:
- Porter’s Pass (rock fall, landslide, debris flow, underslips)
- West of Paddy’s (rock fall)
- Paddy’s Bend (rock fall, landslide)
- White’s Bridge (rock fall, landslide)
- Waimakariri Bluffs and Cornishman’s Rise (rock fall, landslide, underslips)
- The Deviation (rock fall, underslips, flow)
- Otira Gorge (debris flow, landslide, rock fall, underslips)
- Bealey Spur (rock fall, landslide, underslip)
- Otira A, B and C (rock fall, rock flow)
- Craigieburn Cutting (rock fall, landslide)
The issues experienced at these sites are typical for their general area. Consequently, this Study has developed a ‘Corridor Management Strategy’ approach over an individual site approach, which is considered a more cost effective solution to reducing natural hazard risk along the route.
Last updated: 12 November 2009
