The project had involved ground stabilisation both above and below the road, including the construction of an earth wall about 70m long and 11m high.
Rotorua Lakes Council's infrastructure group manager Stavros Michael said the months of roadworks had also required "substantial work" to make the site safe.
Infrastructure group manager Stavros Michael at the Rotorua Lakes Council. Photo / File
"The contractors faced some challenges with that, as well as with the work to stabilise and reinstate the road."
The road was currently open, but it was down to one lane with traffic signals in the area of the works.
Michael said the project had been delayed by weather and additional challenges at the site, but that was always possible because of the nature of roadworks.
The challenges included "soil saturation, a groundwater spring under the road formation that required special management and controls to avoid a major road collapse and further slope erosion which occurred during construction and required the road to be closed for a period due to safety concerns".
"Unscheduled road-widening which had to be undertaken was finished prior to Christmas, along with ground stabilisation works above and below the road."
UPDATE – Paradise Valley Road remains closed while contractors continue to make the road and the new embankment safe. It...
"The project is likely to be finished by the end of this month, again, this will be dependent on any further weather delays or unforeseen issues that may arise.
"The number of staff a contractor has on site at any given time will be dependent on the specific work under way and the potential at any time for deployment elsewhere to undertake emergency works that need immediate attention, such as damage caused by weather events."
Paradise Valley Rd works in mid-February 2019. Photo / Stephen Parker
Michael said there was a number of contractors needed for different roles in the project, and they and the council all wanted to get the work completed as soon as possible, with the least possible disruption.
"Just like when you are building a house, they all need to be lined up in terms of timing. When delays occur, that then has a flow-on effect and sometimes there is a need for re-scheduling of work."
He said the site was likely to remain open with one lane and traffic signals for commuters until the work was completed.
Paradise Valley Springs Wildlife Park owner Stewart Hamlett was positive about the project.
"The council is working on it and they will get it sorted ... I absolutely think it will be effective and will make the road stronger than before. They have fixed other slips and they have ended up better than before. We are getting a plus out of a negative."
He said, "these things take time".
Paradise Valley road washouts in August 2017. Photo / File
Hamlett said it had been a busy summer for his business, when asked how it had been affected by the closures and road changes.
Fellow Paradise Valley resident John Moore said he was disappointed the works had taken so long to get going.
"I think the damage could have been prevented with earlier long-term maintenance. There seems to have been a reactive not proactive approach from council."
Paradise Valley road washouts in August 2017. Photo / File
He said the road closure affected his ability to run his small business and the amount of work he could do each day.
"I have reservations about if it will work in the long-term due to the spring's ability to erode the earth underneath and around the road."
Another resident, who wished to remain anonymous, said only time would tell if the roadworks prevented further slips.
"I will be interested to see how the road fares when we next have heavy rainfall. I am sort of on edge until then. I have to travel into town for work each day so closures are a real pain for me."
A slip that closed a part of Paradise Valley Rd in April 2017. Photo / File
In response, Michael acknowledged that projects like the Paradise Valley Rd works could be disruptive and frustrating for those impacted.
He said the project had needed extensive engineering considerations and design, and if residents had concerns he was happy to speak to them directly.
