Jade Lake is a proposed development in Queenstown, New Zealand. The location boasts breath-taking open views towards The Remarkables mountain range and Lake Wakatipu. The development consists of apartments, terraced, duplex, and stand-alone units constructed on moderately to steeply sloping terrain either side of a gully system.
Queenstown is the adventure capital of New Zealand and an internationally recognised premier visitor destination. Famous for its natural beauty, iconic views and unique outdoor lifestyle, Queenstown not only attracts tourists through the year but is a perfect spot to call home.
ENGEO provided geotechnical support during Stage 1 of the development. Specifically, this is related to works within the gully feature that bisects the property.
Debris-flow hazard assessment – This included a desktop assessment, including a review of historic air photos and QLDC LiDAR. ENGEO followed this up with a site investigation to ground-truth potential zones of source material and confirmed geomorphic parameters for our modelling and analysis. The analysis consisted of assessing basin morphometric variables, such as Melton’s ruggedness number (R) and watershed length, differentiating between a debris-flow dominated catchment and a fluvial dominated catchment.
Earthworks Design Support – Field mapping of rock outcrops for stability, followed by slope stability modelling of placed fill within the gully, was also completed. This modelling informed the recommendations relating to fill specifications, maximum safe slope angles for permanent fill, and temporary secure slope angles during construction.
The development required a large amount of material to be removed from the site. Due to a potentially high cost, ENGEO looked into the feasibility of backfilling the gully system, therefore keeping the site won fill on site. This required the team to assess how the relocation of the channel would impact the geotechnical hazards that affect the site and find ways to mitigate them.
“Thanks for the report, we really appreciate the effort made to get this out in the tight timeframe. . . I’ve skimmed through and am really happy. Cheers again” (Development Manager – Jade Lake)
ENGEO Team – Sam Murray, Jacinta Morgan and Richard Justice
