Walkers and cyclists trying to shelter from the rain on Saturday had a narrow escape when a rockfall occurred on a section of the popular Upper Clutha River track just after noon.

Andrew MillarĀ  crossed over soon after it happened and said two visibly shaken locals warned him about the slip after they heard the rocks and debris coming down above them.

The debris came down just outside the area of track where signs warn of the danger of rockfalls and stopping.

Department of Conservation spokeswoman Nicole Sutton said the Outlet track between the Outlet Campground and the Hikuwai Link Track would be closed until further notice due to the clay bank slumping on to the track.

“DOC will not be doing track work until it is safe for staff to work below the bank that is slumping. “We plan to undertake a geotechnical assessment of the area to ensure public safety,” Ms Sutton said.

Signs were in place and there was an alert on the Doc website.