She said council staff were did not know when the walkway would reopen because geotechnical investigations had to be done before any remedial work could be carried out.
"We are aware this is a very popular route for walkers, joggers and cyclists but this is another significant slip within an unstable area of the riverbank," Miss Sheedy said.
"We've been advised there is no immediate risk to walkway users but we need to make sure and ask them not to use the walkway at all."
She said it effectively meant the walkway was closed from London St through to the southern side of the Claudelands Bridge and users would have to leave the path at the bridge and walk down Victoria St, rejoining the path at London St.
The area of riverbank is prone to slips during wet weather. A section of the walkway was closed in July 2008 because of a slip.
The council would not know how much it would cost to fix the slip until it had been assessed but the 2008 slip cost $718,000 to repair, giving the council its largest landslide bill in recent years.
Another recent slip at the Te Hikuwai Reserve in Flagstaff in mid-2006 cost $428,000, and one on Fairfield Esplanade in February 2009 cost $123,000.
The council had insurance to cover much of the work, Miss Sheedy said.
Meanwhile, another smaller slip that swept away part of the bank south of SkyCity Casino was also believed to be the result of extensive rain at the weekend.
Part of that section of the walkway has been fenced off and the city council is assessing what can be done to fixit.
Miss Sheedy said another closure was possible if more heavy rain caused other landslips.