The Ngaio Gorge Road in Wellington is still scheduled to open this afternoon after being closed for weeks by rockfalls, but that could change, with rain expected later today.
The gorge - which is a major route for motorists in and out of the city - has been shut since a large slip came down in late July.
Despite heavy rainfall overnight, the Wellington City Council said one lane of the gorge was still scheduled to reopen for peak traffic later today.
But further rain was expected this afternoon, and the council said it would reassess the situation at about 1pm.
Over the weekend, council staff worked on a realignment of the uphill lane and secured a line of shipping containers to protect the road from any further rockfalls.
During off-peak periods the road just above the slip site will continue to be one-way only, while work continues on the construction of a retaining wall.
The site will have a restricted speed limit of 30km/h in both directions.