A 2019 report said multiple groynes would likely be required to retain sufficient sand. File pic Photo: RNZ / Tim Brown
The Dunedin City Council is investigating whether a trial groyne can be built at St Clair Beach to combat erosion.
The cost estimates are between $195,000 and $570,000 for consenting and construction.
During the public excluded section of Tuesday's council meeting, councillors voted to find out from the Otago Regional Council if it would be permitted.
City mayor Jules Radich sought to reinstate the wooden structure at the beach during his campaign for the mayoralty.
His notice of motion was rejected earlier this year - it came after annual plan consultation had closed and the city's Coastal Plan was adopted.
The cost to reconstruct a single groyne is estimated to be between $180,000 and $320,000 depending on the materials used.
The consenting cost could range from $15,000 to $250,000 and it could take up to 12 months depending on the consents needed.
The original 2019 design drawings showed a single row of timber piles that could be built during low tide in summer.
In the city's coastal plan, groynes were included as a potential management option to hold the coastline in its current location.
The report said multiple groynes would likely be required to retain sufficient sand.
"Alternatively, large import sand volume and periodic top-up would be expensive and disruptive," the coastal plan said.