Tauranga City Council staff have been working through a tender process with contractors as they seek a long-term solution to the slip that buried part of the Base Track in 2017.
The preferred plan is to re-route a 250m section of the track along the beach, where it would be less likely to be affected by slips in future, the council said in a statement.
However, the contractors have indicated that the cost of repairing the Base Track under this plan would be significantly higher than the $2.2 million that has been approved by the council.
Staff are exploring options with the contractors to deliver the realigned track more cost-effectively.
Staff will report to a council meeting on April 16 with detail of the delivery options, including the cost, risk and timing implications, the statement said.
Deputy mayor Kelvin Clout said that staff would hold further discussions with contractors to see if some of the cost issues could be resolved. In either case, alternatives might have to be considered.
"Mauao is a precious taonga," he said. "The slip occurred in difficult terrain in a culturally and historically significant area, and it's important that we ensure the right outcome for the Base Track."
The 14m-wide slip buried the section of track after ex-Cyclone Debbie hit in April 2017.
Box steps were built up and around the slip to allow walkers and runners to complete a circuit, but these steps are not wheelchair or pram accessible and present a challenge to less-able people.
Under the current plans and timeframe, the repairs would begin later this year, with the new section of track to open sometime next year. This timeframe would be firmed up once the consent and funding process is completed.
As part of the consent process, Council has been working with Heritage New Zealand on a plan to make public the results of any archaeological discoveries at the slip site.
Heritage New Zealand senior archaeologist Rachel Darmody said, "This is an important place archaeologically and it is really good that a careful process is being followed to ensure disturbance is being kept to a minimum".