Dart Valley track reopened

 

The lake which formed behind the Dart Valley landslip is expected to remain for several years. Photo by Vladka Kennett.
The lake which formed behind the Dart Valley landslip is expected to remain for several years. Photo by Vladka Kennett.
A ''very temporary'' track has been cut through the Dart Valley, detouring around a massive landslip and newly formed lake to restore tramping access to the area.

Department of Conservation partnerships manager Greg Lind said the alternative track - estimated to have cost about $10,000 to create - replaces about 2km of the original, which traversed from Dredge Flat to just past Sandy Bluff on the Rees-Dart circuit, made impassable following a massive slip earlier this month.

It would be in place until a permanent track was completed, which was expected to cost about $500,000.

The department had applied for funding to build the permanent track.

If the project is approved, work could be begin by the end of this year.

The landslip formed within an existing zone of instability in the Te Koroka/Slip Stream area, which had been depositing fresh material into the valley for more than a year.

When rainstorms caused the massive landslip on January 4, the obstruction caused a new lake to form upstream.

Mr Lind said Doc and GNS Science believed the lake would be ''with us for quite a long time - years.''

''It's not going to disappear soon.''

While a large amount of sediment and wood debris was washing down the Dart River, GNS considered there was ''no additional hazard'' to the lower Dart.

Mr Lind said Doc rangers from the Wakatipu and Central Otago had worked over the past week cutting the new route through the steep, thickly forested Dart Valley.

The alternative route was ''rough underfoot'' and would be difficult to traverse, but it would lead trampers safely past the lake and landslip.

''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,'' Mr Lind said.

It was estimated the ''roughness'' of the track would add up to two hours to the standard walking time between Daleys Flat Hut and Chinaman's Bluff, which normally took between three and a-half and five and a-half hours, he said.

It was imperative trampers stayed on the alternative track at all times.

''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 will enjoy great views of the lake and landslide from this route, particularly on Sandy Bluff.''

• GNS has posted a video of the landslip on You Tube, which can be seen at: youtube.com/watch?v=Y6vs-lnBqwY.