- Milton Road is now closed for Wednesday, and will only open once sluicing is completed.
- People are urged to stay away from the site.
- The slip initially happened on 29 August, cutting off 50 homes.
Residents impacted by a slip in Greymouth have been praised for being patient as contractors worked to clear and stabilise the ground.
A number of slips, including one that blocked Milton Road, occurred at the end of last month, following bad weather.
It left around 50 properties cut off, with residents being unable to get in and out of their homes for a few days.
The council on Wednesday begun sluicing material, with the road closed until the operation is complete. There would also be no pedestrian access during the operation.
A helicopter will fly clockwise around the Arnott Heights community and drop monsoon buckets of water onto the slip site, working from the top down. It will not fly directly over houses, and each flight would take around two to three minutes.
There was a technical glitch with the helicopter on Wednesday morning, with it only being able to drop a few buckets before another helicopter replaced it just before midday.
Measures were in place at the bottom of the slip site to channel material away from houses on Milton Road. However, access to the properties would also be cut off, so residents who wanted to come and go were advised to vacate for the day.
Mayor Tania Gibson said locals had been listening to advice.
''Impacted residents, they have been very patient. Again the fatigue is starting to set in within the community, but I also think a bit of excitement has set in today as well with the action that is happening.
"But you know, our thoughts are with the community and what we are doing is trying to get them a permanent solution, but first we need to address this to get that underway.
"I think they've all been briefed today on safety in the area, and we will be keeping them updated as to how the work goes, depending on how much comes down and how long it takes for the contractors to be able to clean that up, if it does come down.
The council urged residents and traffic to stay away from the area while the operation was carried out. It also asked locals to respect residential properties and park considerately.
The cordoned area will be expanded during the operation and pedestrians were not to enter the operational area.