ANDERSON — An Ohio gambling referendum passed Tuesday could be detrimental to Madison County’s most renowned destination and the towns that depend on its tax dollars.

Ohio voters approved a referendum during Tuesday’s election to open four casinos in the state. It passed with 53 percent approval.

The casinos will be located in Cincinnati, Columbus, Cleveland and Toledo.

“This is the most serious competitive threat that we’ve seen in Indiana since gaming started,” Jim Brown of Hoosier Park said Wednesday.

“A little over 5 percent of our business right now comes from Ohio,” he said.

When Ohio casinos open, he said, Hoosier Park could stand to lose 10 percent of its business due to Hoosiers living on the border choosing Ohio over Indiana.

The casino was already struggling under the weight of a $250 million licensing fee imposed by the state.

In late October, news broke that Hoosier Park’s parent company, Centaur LLC, defaulted on one of its loans.

The company also filed voluntary bankruptcy petitions on two of its Pennsylvania casinos.

An analysis by the Legislative Services Agency, or LSA, predicts that Indiana could see a $269 million drop in gaming revenue when the Ohio casinos open.

About $9 million of that would come from losses at Hoosier Park.

Indiana casinos account for about $900 million in tax revenue for state and local entities annually.

The LSA report indicates that an Ohio presence in the gaming industry could cause the Hoosier state to lose $100 million in tax revenue.

Madison County Council President Bill Savage watched Ohio’s Tuesday election closely, realizing that the vote would have a ripple effect on Indiana. “When I saw it pass, I knew it wasn’t a good thing for Madison County,” he said.

A recent tourism report revealed that Hoosier Park accounted for $109 million in tourism spending in the county in 2008.