The NZ Transport Agency is using a helicopter to drop monsoon buckets of water over a massive slip that is currently blocking State Highway 2.

The buckets hold thousands of litres of water and are hoped to expedite the clean up in a section about halfway through the Waioeka Gorge.

The Transport Agency's Bay of Plenty highways manager, Niclas Johansson says the highway has been closed since about 5.30pm yesterday after large amounts of rick and other material came crashing down which smashed through a section of steel rock fall fence.

The fence will now have to be cut up before it can be removed.


Motorists are being urged to expect lengthy delays as contractors clear the road.

"Our contractors have been working since early this morning to clear enough of a lane that we can let people through however it is under stop/go traffic management and there will be closures at times as the contractors need the space to continue clearing the slip," he says.

"People should expect delays of up to 30 minutes if they are travelling through."