Oamaru's historic harbour breakwater is being repaired.
Waitaki District Council water services and waste manager Martin Pacey said the repair work, awarded to contractor Rooney Earthmoving ''a couple of months ago'', had been under way for four weeks and could be completed before Christmas.
''It depends quite a bit on the sea state,'' he said.
''There might be some work that carries over.''
The harbour breakwater, built during the 1880s, was checked regularly by a specialist consultant, who recommended repairs originally scheduled for 2016 should be done this year, following damage by heavy seas.
''Rock armouring'' was required as preventive maintenance, Mr Pacey said.
The contractor would armour about 70m of the breakwater that had ''lost some protection'', he said.
Large boulders, weighing up to 10 tonnes each, had been carted from a nearby quarry and stockpiled at the beach, Mr Pacey said.
After the boulders were in place, concrete would be poured into some ''voids'' beneath the breakwater.
Crews, working at low tide, built ramps to get up on to the breakwater and had started placing the large rocks on the sea side of it over the past week.
In a media release in July the council said: ''The harbour breakwater ... is seen as a significant asset for a small local fishing industry and recreational users and has the potential to be developed for future eco and water-based tourism activities.''
The original breakwater was extended and raised in the 1930s and 1940s and had additional strengthening work done in the 1950s and 1960s.
''However, most of the strengthening work has been lost by continual pounding of the sea,'' Mr Pacey said.
The repair work was on budget, but at the upper end of the original $200,000 to $250,000 estimate, he said.
The estimated cost of a new breakwater was $24million to $45million.
