Work is expected to begin early next month to get the Haast
Pass reopened to two-lane traffic fulltime by the middle of
The New Zealand Transport Agency has spent about $3.8 million
to date managing the slip at Diana Falls on State Highway 6,
which occurred during heavy rainfall on September 10. Since
then, the road there has been cut to single-lane traffic from
8am to 7pm, and the route closed at night.
There had been delays in getting the work under way as NZTA
finalised what was needed on site, completed the design,
sourced material and appointed a contractor - which would
happen in the next fortnight, senior network manager Mark
The first phase of the work will be building a fence draped
up against the 30m vertical rock face that rises up from the
road, with a large opening at the top of the rock face
channelling any falling material against the rock face to
prevent it from falling on the highway.
A temporary fence will then be built at the top of the slope
to enable the bigger, up to 200-tonne rocks at the head of
the slip to be broken into smaller, one-tonne rocks for
Finally, a fence will be built about one-third of the way up
the slip which has the dual role of catching any larger rocks
that might move off the slope and to contain gravel expected
to continue to wash down the rock face as the slope
re-establishes its natural stability level.
''At this stage it is expected the works will begin within
the next two to three weeks and be completed by the end of
May. However, weather will be a significant factor in
achieving this date,'' Mr Pinner said.
Additional traffic delays were likely throughout the day to
complete the work and NZTA would provide as much warning as
possible to ensure motorists could plan their travel through
The cost of the work was not known until a contractor was
appointed and the specific detail of the programme finalised.