Slip on Mangapurua Track blocks access to Bridge to Nowhere

A major slip on the Mangapurua Track has blocked access to the Bridge to Nowhere. Photo / Mountains to Sea

The Mangapurua Track on the Mountains to Sea cycle trail is closed due to an “impassable” slip.

The slip was discovered on Thursday by a trail concessionaire who reported the hazard.

Because of the slip, people will not be able to access the jet boat at the end of the trail, but the Kaiwhakauka and Waipuna trails are alternative options.

The area of trail is made from papa rock, a soft blue-grey mudstone in contrast to the solid volcanic rock found closer to the Central Plateau. Papa is also found in areas such as the Kaiwhakauka and Whanganui River valleys.

The softness of the papa when wet means the trail is constantly being reshaped.

“It’s a challenging geology,” Department of Conservation senior ranger Jim Campbell said.

“The logistics are so hard in here.”

This area of the trail is closed in winter, and often following severe weather due to the increased risk of slips.

The recommended time to ride the section is in the drier and more settled months from November to April.

According to the Mountains to Sea route notes, the papa stone trails are “a dream to ride on when it’s dry. In the wet, however, it has been known to snap derailleurs, destroy brakes and test the mettle of even the hardiest riders”.

Riders are encouraged to keep an eye on the trail status because of the unstable environment.

“You can’t really tell when it’s going to fracture. It can be wind, it can be rain, it can be heat,” Campbell said.

Work to repair the track and ensure safety for riders was under way.

“We’ll be working on the site with some abseilers to make the site safe so we can get our staff in there to clear the debris,” Campbell said.

Because of the logistical difficulties, there was no confirmed date for when track would reopen but it was hoped to be later this week.

Olivia Reid is a multimedia journalist based in Whanganui.