The Waimana Gorge linking Tāneatua and Ōpōtiki is expected to re-open to one lane later today after a large slip blocked the highway on Monday night.

A helicopter carrying a monsoon bucket is helping clear the slope above the highway by sluicing loose material with thousands of litres of water.

The Waimana Gorge is expected to reopen to one lane later today. Supplied Photos.

'This is a large slip, approximately 2000 cubic metres of material has come down and our contractors have been working hard to clear it and get the road open again,” says New Zealand Transport Agency's Bay of Plenty highways manager Niclas Johansson.

'The helicopter will help bring down any unstable material above the slip. Once this is complete, concrete barriers will be installed and one lane will open to traffic under stop/go traffic management so drivers can get through.

'At this stage we expect to have one lane open this evening however people will experience delays of five to 10 minutes due to the traffic management onsite.”

Stop/go traffic management will remain in place until the site is assessed as safe to fully reopen.

The highway, which links Tāneatua and Ōpōtiki has been closed at Waimana since 3.30am on Monday when a large amount of rocks and other material came down following heavy rain.

Traffic through to the East Cape, Ōpōtiki and Gisborne is detoured is via Whakatāne and Ōhope.