Contractors are scaling 40-metre cliffs to remove trees and blast large rocks which are threatening an area along State Highway 29.
Smoke plumes billowed into the air as rock faces on the Ruahihi Bluffs slope came crashing down yesterday in an organised blast.
About 10 contractors were involved in the rock blasting on the Ruahihi Bluffs slope, about 17km west of Tauranga near the Ruahihi Power Station.
New Zealand Transport Agency acting state highway manager Andrew Scott said contractors wore abseiling gear and used specialist excavator equipment with grapple and tree chippers to remove overhanging trees and dangerous rocks that threatened to fall on road users below.
About 10 others were involved in traffic control.
Mr Scott said yesterday's one-hour road closures at midday and 2pm focused on blasting the rock which overhung the road, then clearing the road to enable reopening. He said yesterday's first closure at 10am was cancelled because of rain but the midday and afternoon closures were successful and significant material was removed.
The road was due to be closed periodically today and tomorrow at 10am, midday and 2pm to complete the remaining work.
Alternative routes include State Highway 2 north towards Katikati, State Highway 36 south towards Ngongataha, and a diversion route will be in place on the Tauranga side of State Highway 29 along Poripori Rd, Crawford Rd and Wairoa Rd.
Mr Scott said the road closure times had been timed away from the start and end of the school day to avoid disruption.
Work on the slope area surrounding State Highway 29 began on Saturday.
Work is scheduled to continue through to tomorrow afternoon.