The archway, which has been deteriorating in recent years, has been fenced off since February, when a routine inspection revealed a cavity and crack in one of the pillars.
Waitaki District Council parks officer Lindsay Hyde said the steel inside the archway had also rusted, expanded and "blown out" a lot of mortar, so the structure was not safe.
Work to take apart the archway started last week. The plan was to remove the arch and rebuild the two pillars, Mr Hyde said.
The cost of reinstating and capping the pillars was "significantly less" than fixing the archway as a whole, he said.
"So that’s why we’ve gone that way — and it will look quite nice."
Originally, the council had planned to reinstate only the right pillar, as the left pillar had not shown any "major issues".
"However, when the guys took off the top, we found the way it was constructed in the past would make it a bit weaker for the future. It made sense to rebuild both now and we get a good lifespan out of both of them."
It is not known exactly when the original archway was erected, but in May 1934, the council’s reserves committee of the time recommended a rock wall and an entrance gate be erected at Awamoa Park at an estimated cost of £75. Instead of going out for tender, the archway was built in-house, Mr Hyde said.
