State Highway 35 collapse: Large rocks in place, temporary single lane open tonight

"Great progress" is being made at the site of the State Highway 35 collapse in the Eastern Bay of Plenty, as more heavy rain bears down on the region.

The stretch of highway between Ōpōtiki and Te Kaha collapsed into the Motu River on Wednesday evening, forcing the closure of the road between the Bay of Plenty and East Coast.

Waka Kotahi NZ Transport Agency regional manager of maintenance and operations, Rob Campbell, said the team was making "great progress" at the site today.

The road was opened to light traffic via a temporary single-lane track on Saturday evening but had been closed today so "stabilisation works" could continue.

Campbell said large rocks were being positioned at the base of the bank for the river flow protection.

A section of SH35 near Te Kaha collapsed into the Motu River. Photo / NZME

This would offer the road more protection from the river rise that will occur with the rain forecast, he said.

A heavy rain watch is in place for Bay of Plenty east of Kawerau until noon Tuesday.

The temporary pavement was "holding together well" - and the track would open to light traffic again from 5pm until 8pm this evening ahead of the heavy rain forecast.

"Waka Kotahi will reassess tomorrow morning and only reopen the temporary track if it's safe to do so."

Campbell said SH35 had been closed near Motu River bridge since Wednesday night following severe cracking and a section of the eastbound lane falling into the river.

It was not possible to give a timeframe for when the road would be back to functionality.

"We are still very much in emergency response mode. Safety is paramount."