Tramping access through the Dart Valley has now been restored with the completion of a new walking route that detours around the massive landslide and newly formed lake. A team of four DOC Rangers from both the Wakatipu and Central Otago Districts have worked steadily over the last week to cut the new route through the steep and thickly forested Dart Valley. The alternative route replaces about 2km of the original track.
Conservation Partnerships Manager Greg Lind explains “The alternative route is rough underfoot and will be difficult to traverse. However the route will lead trampers safely past the lake and landslide. The route will not be passable in heavy rainfall as it crosses several streams that will quickly flood and become hazardous for trampers to cross”. Greg estimates “the roughness of the track will add up to 2 hours to the standard walking time between Daleys Flat Hut and Chinamans Bluff (usually 3.5 to 5.5 hours).”
Greg warns “Close to the landslide debris the river is cutting through forest, and trees have been falling into the river. There are areas of soft quicksand-like sediment, loose wood and rock debris, and river levels may still fluctuate irrespective of rainfall. Trampers must remain on the alternative route at all times for their safety. Trampers will enjoy great views of the lake and landslide from this route, particularly on Sandy Bluff. There is no need to leave the track for photos of the landslide.”
The Dart Valley landslide has formed within an existing zone of instability located in the Te Koroka / Slip Stream area. This zone has been depositing fresh material into the valley for over a year however recent rainstorms have led to the much larger landslide on January 4th. There remains a large amount of sediment and wood debris washing down Dart River. However GNS Science considers the landslide debris and lake currently add no additional hazard to the lower Dart River below the landslide. No abnormally high flows should be expected, other than those that would result from high rainfall. GNS have posted a video of the landslide on YouTube.
The Rees/Dart track is a popular 4 to 5 day circuit in the Mt Aspiring National Park. The circuit received about 2,000 overnight trampers per year. A further 3,000 people per year undertake a shorter day walk from either the Rees Valley or Dart Valley road end.