Tauranga City Council spent about $300,000 on signs within the city boundaries during the same period - $20,000 more than the previous year.
Council transport operations manager Martin Parkes said most damage was unintentional.
Give-way, stop and parking signs were damaged most often as there were more of them, he said.
"Usually it is the sign pole that is damaged from being hit by vehicles, rather than the sign itself. Very occasionally signs get stolen."
There were about 12,500 road signs in Tauranga city, he said. Tauranga police acting Senior Sergeant Steve Hindmarsh said vandalism of street signs was common.
"It usually happens in the dead of night," he said.
"There's a fair bit of it going on but we appreciate calls from members of the public when they see it."
Tauranga Mayor Stuart Crosby said the cost was frustrating. Road signs were incredibly expensive to buy, mainly due to the materials they were made of, he said.
"They are always getting damaged by accidents, for the most part, but a lot are straight out vandalism, which is incredibly frustrating. I suspect the people vandalising them do not comprehend the cost," he said.
"The damage around the city from vandalism and tagging is several hundred thousand dollars a year and the ratepayers end up paying for just about all of it."
If taggers and vandals were caught, the council often arranged a meeting with them to explain the cost of the damage. On two occasions, taggers had apologised publicly to the council, Mr Crosby said.
"We do take it seriously. It's a stupid thing to do. [Damage to street signs] is dangerous to drivers and pedestrians."
Western Bay Mayor Ross Paterson agreed the cost was a nuisance. People needed to know just how much road signs cost, he said.
"I don't think the public at large realises how expensive the signs are. Then when they see people vandalising them and shooting them up like they do in the more rural areas, they realise it's just blatant vandalism of property. It's shocking though that most of it is being done by a few mindless people," he said.