DOC staff got more than they bargained for on a routine maintenance visit to the Mangapurua Track on Wednesday. Biking up to clear windfalls, rangers Shane Woolley and Hannah Rainforth were literally stopped in their tracks by a massive slip.
The slip is near the iconic Bridge to Nowhere in the Whanganui National Park and appears to have happened either late Tuesday afternoon or evening. Mr Woolley estimates it is around 60 m across. “It was large enough to block the Mangapurua Stream for a while there,” Woolley reported. The workers attempted to cross but quickly assessed that the situation was too dangerous. “The spill was still moving,” noted Mr Woolley.
Slip on the Mangapurua Track
DOC Programme Manager George Taylor says the slip occurred at a location where there is no knowledge of past landslide events. Mr Taylor stated, “The weather will have to settle before it is safe to work at this location, and it will be some time before an assessment can be made to determine the construction of a track across this area.” The affected section of the track is now closed. The Bridge to Nowhere is accessible from the river, but there is now no access from the Ruatiti or Kaiwhakauka ends. The Mangapurua Track is part of the Ruapehu-Whanganui Trails, which is itself part of the NZ Cycle trail network. It is also a preferred route of the Te Araroa track network.
The Mangapurua Valley is famous for its slips, due to its geology. The landscape is predominantly papa rock, which is prone to landslides and is easily eroded during downpours. The current track follows an old road, constructed partly to allow access for the early settlers. After numerous slips the road was abandoned, making farming in the region difficult and impractical. The settlers departed, leaving the now famous ‘Bridge to Nowhere’ as a lasting monument to this difficult terrain – a terrain the DOC track cutters are now all too familiar with. “It will certainly be a big job but we’re fairly confident that we’ll have it open in the near future,” said Mr Taylor.