In the back of Waimanalo, Glenn Martinez owns and operates Olomana Gardens.
Martinez is the president of the Hawaii Farmers Union United.
He said he recently learned that starting next summer, the city no longer considers horses as livestock, keeping farmers and ranch owners who board horses from receiving large agricultural tax incentives.
"Right now if you dedicate your land to Ag, you only pay tax on 1% of its value and if we cannot dedicate our land to agricultural, we will pay 100% taxes. That will be a killer," Martinez said.
Martinez added the increase in taxes alone is enough to wipe out the island's ranching community.
"You won't have the rodeos, you won't have the horse shows; an entire economic industry here," said Martinez.
Down the road at Circle Z Ranch, owner Debi Roblin says without the agricultural tax breaks she couldn't afford to maintain the horse stables.
"I cannot afford the taxes and my workers live here. Their families live here. Some of them have worked here for twenty years and their fathers before them," said Roblin.
If ranches are forced to close, horse owners would have to find a new place to board their horses.
At a town hall meeting in Waimanalo Monday night, City Council member Ikaika Anderson admitted the city slipped up.