Three Department of Conservation staff spent much of
yesterday attempting to establish a ''new line'' of track
from Dredge Flat to just past Sandy Bluff on the Rees-Dart
circuit after a massive landslip made the section impassable.
Doc services senior ranger Richard Kennett said parts of the
track had been 90m above the river, but were now about 70m
While parts of the section were safe, those had to be linked
to new tracks over a distance of about 3km in what would be a
''total realignment'' of that section of the popular walking
It was not yet known how much that would cost, but it would
be covered by funding from the department's national office,
set aside for emergency repairs to tracks and facilities.
Doc partnerships ranger Chris Hankin said trampers and
walkers were still able to access the Rees section of the
track, but had to turn around and go back the same way,
rather than completing the usual circuit.
On average, 2000 people a year walked the Rees-Dart in a
multi-day circuit, with another 3000 people undertaking a day
walk from either the Rees or Dart road ends, he said.
Mr Hankin advised people to heed warnings about the closure
of the Dart section.
''Sometimes people see closures and think we're overreacting
... there is no way [you can get through the affected
At the site yesterday viscous cement-like sediment could be
seen flowing down the face of the slip into the Dart River,
taking with it large rocks, with material around the site
likened to quicksand.
The lake, which began forming on Saturday afternoon, had
risen about half a metre since Monday, Mr Kennett said.
It would get larger, but would ''come and go'' during periods
of settled dry weather and heavy rain or snowmelt.
''But, we can expect it to get bigger before we see it
The slip had been monitored by Doc and Ngai Tahu for several
years and it had been noted by GNS principal scientist Simon
Cox as ''probably one of the most active slips in Otago and
probably in New Zealand''.
Dr Cox did a report on the slip in 2009 and said in 1965
about 15% of the fan area at the bottom of the slip was
covered in debris - by 2009 65% was covered. Since then the
entire alluvial fan had been covered in debris.
GNS was now writing a second report on the slip as well as
looking towards the scientific lessons that might be learned
from it, such as the impact landslips might have following an
Alpine Fault earthquake.