Council engineers said it was fortunate the damage was reported quickly and contractors were able to remove graffiti before the paint hardened. A delay would have increased the cost of cleaning the signs.
A broken stop sign had been replaced and given a concrete foundation after a similar attack a few months earlier.
Road sign vandalism and theft was an ongoing problem in the Far North, Mr Edmondson said.
A spot survey a few years ago found that, at any one time, road signs worth $20,000 were missing or damaged. The annual cost of repairing signs averaged almost $100,000, he said. The cost is borne by ratepayers.
Senior Sergeant Chris McLellan urged people to contact police beforehand if they were planning a celebration, so they could help keep hosts and guests safe. The aftermath of the Kerikeri party had left "some pretty embarrassed people," he said.