Manukau City Council is dropping monsoon buckets full of water in an effort to move excess soil sitting on a landslip that has paralysed Kawakawa Bay.
The landslide struck last month causing houses to be evacuated and blocking the suburb's main route to Auckland, a detour adding an extra 100km to the trip.
Manukau City Council organisational performance director Robyn McCulloch said the council wanted the road reopened by the start of October.
A helicopter with a 1300 litre monsoon bucket has made several trips over the hill at Kawakawa Bay today and dropped more than 10,400 litres of water.
"Over the weekend, barriers were put in place to help contain material brought down from the landslip.
"More than 100 truckloads of unstable earth have to come down from above the road.
"It's early days yet, and there are more water drops to come. If this watering operation is successful, it will take some time to truck away the material and clean up the base of the landslip."
The helicopter would continue dropping water on the area tomorrow.
Meanwhile, the council said that some Bucklands Beach residents, evacuated after a separate major slip last month, have been allowed to return home.
Residents of 114, 120, 122a and 124 on Clovelly Road in the east Auckland suburb, returned to their homes over the weekend.
The residents were asked to leave as a precaution because of the danger posed by the slip.
Other houses and a walkway leading down to the foreshore remained off limits.