Rocks Road opened late on Sunday night.
The state highway opened to traffic in both directions at 11.30pm and, as a safety precaution, water filled safety barriers, and a 30 kmh temporary speed limit will be in place at the slip site.
Over the weekend, specialist abseilers removed a failing concrete crib wall, loose plants, and material from the face of the cliff above the highway.
An NZTA spokesperson says the debris posed a substantial risk to the road and the safety of drivers, cyclists, and pedestrians.
Fire and Emergency New Zealand (FENZ) staff also provided targeted sluicing to remove loose material from the cliff and road surface.
Their efforts saved approximately one day of work for contractors, according to NZTA.
