"Our current approach is first to clear slips, reform roadside drainage and clear culverts. Since underslips require careful investigation, these will come second in reinstatement," he said.
Mr Leitao said public notices had been issued and new signage was being placed at the start of the Whanganui River Rd, near its intersection with State Highway 4.
"The signs are advising drivers that, while it's officially open, the road should be used only when necessary. And campervans are advised to use an alternative route north."
He said "road closed" barriers were in place just beyond Jerusalem, as the road would be impassable 2km south of Pipiriki on the Ruapehu district side for a number of months.
"The most important message is that, if travelling on this road is absolutely necessary, then people must drive at safe speeds for the conditions and take additional care in wet weather," Mr Leitao said.
In terms of paying for the River Rd repairs, he said, the NZ Transport Agency would be making a significant contribution and the council was working with the agency "to get the maximum possible contribution to reduce the cost to our ratepayers".