Supporters and critics of Issue 6 are making their final arguments as the May 6 ballot nears.

Supporters and critics of Issue 6 are making their final arguments as the May 6 ballot nears.

Tom Stalf, president and CEO for the Columbus Zoo and Aquarium, which is seeking a permanent 1.25-mill levy, said the return is well worth the investment.

For the nearly $19 million the zoo receives annually from its current 0.75-mill levy, there's a $238 million economic impact for the region.

"Those numbers will grow," Stalf said.

The zoo draws 2.2 million visitors a year, making it the No. 1 family attraction in central Ohio, he said. The zoo employs 2,000 people and there are now 200 construction workers building the Heart of Africa exhibit.

"This is about the zoo, but it's also about the community. The other part I love about our relationship with Franklin County voters is it's been going on for 30 years," Stalf said, referring to the first tax issue passed by voters in 1985.

But opponents aren't convinced the additional tax money is necessary and chide zoo officials for not turning over a 30-year master plan until recently.

And then there's the issue of the downtown zoo, to be named Downtown Adventure, a 50,000-square-foot interactive facility zoo officials say would be a welcome educational attraction for inner-city youths.

Dan McCormick, an organizer of Citizens for Responsible Taxation, a group opposing the levy, said zoo and county officials rushed to get the issue on the primary ballot and then played down the facility's significance in the tax request.

Furthermore, it's a luxury that county voters can't afford, McCormick said. Under the proposal, homeowners would pay $44 a year per $100,000 in assessed property value; the current levy costs $21 a year per $100,000 in value.

"I think it's a want, not a need," McCormick said. "A permanent doubling of the tax is asking a lot."

As for the economic-development aspect of the levy, McCormick said he's skeptical of the numbers. Furthermore, the zoo won't lose money if the levy isn't passed, he said.

"It's a fallacy that you can tax yourself into prosperity," McCormick said.

The current levy expires at the end of 2015. The proposed levy would generate $32.7 million a year. The state no longer pays up to 12.5 percent -- 10 percent for property owners and 2.5 percent on owner-occupied dwellings -- of the property tax on new tax levies, said Dave O'Neil, spokesman for the Franklin County Auditor's office.

But should the zoo renew the existing levy amount, the subsidy would remain, O'Neil said.

Stalf argues the levy always has been about maintaining and improving the zoo, which is in southern Delaware County, but technically located in the city of Columbus and Franklin County because of a lease agreement struck more than 40 years ago.

According to the zoo's 30-year plan, Downtown Adventure, which would cost between $50 million and $65 million, represents just 9 percent of capital-improvement dollars.

"We worked really, really hard with our board and our community," Stalf said.

"When we looked and really examined what we were going to ask for, it was for maintaining the current zoo and current improvements."