High-strength resin will be pumped through drill holes into decaying stonework and concrete, to prevent further erosion from the pounding Southern Ocean waves.

Contract company Uretek's southern region manager, Peter Reeve, said the two-part resin set within seconds and was so strong it could lift five-storey buildings.

"It will give the breakwater a new lease of life," he said.

"The resin will be pumped in to fill cavities and reduce settling of the surface stone. This product has a very long life." City council infrastructure director Peter Robertson said broken concrete rendering would also be repaired in the $824,000 project.

"There is considerable settlement in the last 100 metres of the breakwater. We are trying to stabilise it," he said.

"In addition, fenders along the breakwater at water level are to be made good.

"Ladders for accessing the water will also be made good and their supports replaced where required.

"Lighting will also be improved together with construction of a barrier along the edge of the breakwater.

"This barrier will be in a style similar to the seat wall along the promenade at the yacht club."

Mr Robertson said the breakwater surface would not be repaired until additional funding was available. "This treatment will be similar to the work that we have already done along the promenade at the yacht club - a combination of timber, concrete and bluestone," he said.

"We will also preserve the original rails in this area."