State Highway 6 has this morning re-opened again to all traffic from Haast to Makarora following closure yesterday after heavy rain in the area.
The NZ Transport Agency Performance Manager Pete Connors says about 40mm of rain fell in the area yesterday, bringing a small amount of rock and gravel down on to the highway, which has been cleared away.
"The rain eased to drizzle overnight and with less movement at the Diana Falls slip this morning it is again safe for motorists to travel through the area."
He says the slip sits within a challenging geological site and coupled with the forces of nature, it is proving difficult to stabilise and manage.
"As a result, there will be continued uncertainty with access along this section of State Highway 6 when there is heavy rain and this situation is expected to remain for some time yet."
Mr Connors says State Highway 6, from Haast to Makarora, will continue to be closed to all traffic from 6pm to 8am every day as a safety precaution.