Western Bay's council has closed bush walks at Kauri Point Historic Reserve after finding tracks taken out by landslides.
After the weekend's heavy rainfall, saturated ground had given way and caused four new slips that took out walking tracks, according to the Western Bay of Plenty District Council.
Reserves and facilities manager Peter Watson said parts of the tracks had disappeared into the harbour.
He said the area near the cliff face was very unstable with tension cracks appearing.
"Tension cracks suggest there could be further slips and as the reserve borders the harbour this poses a significant risk to reserve users.
"Because of this we've closed the walking tracks through the bush area until further notice, and put up fencing and signage warning people of the danger."
Walking tracks through the grassed area of the reserve were not affected and remained open.
An earlier slip closed vehicle access to the boat ramp and jetty.
The council was monitoring the situation.