With an aging infrastructure and underfunded master plan, the Reid Park Zoo is hoping to drum up support among Tucson voters to back a sales-tax increase to help pay for capital improvements.

A new campaign, “The Future of Your Zoo,” is filing paperwork with the Tucson city clerk Wednesday, seeking permission to collect signatures supporting a small sales-tax increase that would provide a dedicated revenue stream to the zoo, officials said.

“We had over half a million visitors visit the park last year and we know that the zoo has a wonderful diversity of animals that are happy and healthy,” said Reid Park Zoological Society President Nancy Kluge “But the facility really has some vital improvements that need to be made. There’s a 75-year-old water and sewer infrastructure and we have a 10-year master plan that we don’t have the funding for.”

In 2014, the society contracted with Torre Design Consortium on a new 10-year master plan for the 3-acre central area of the zoo, which would include a larger tiger habitat and new pygmy hippo exhibit. The county sought to raise $8 million for improvements in the 2015 election, as one of seven propositions that appeared in a bond plan voters rejected.

“The Future of Your Zoo,” chaired by zoological society member George Ball, aims to collect the 9,241 signatures necessary to get the one-tenth of one cent sales-tax initiative on the Nov. 7 ballot.

The society has been discussing the idea of a dedicated sales tax for about a year, Kluge said.

“It’s a critical time because these changes need to happen for the zoo to be able to keep its accreditation, which is vitally important for the zoo to show the care of the animals and to make sure we can keep animals like our elephants that belong to San Diego Zoo Global,” Kluge said. “The master plan really focuses on spaces that would provide better care for our animals, while making this a facility that Tucsonans can continue to be proud of and that will provide a great space for our children to learn about these animals.”

Councilman Steve Kozachik, in whose ward the zoo is located, said the campaign was taking on a “pretty tough lift,” given the timing.

“They are going to be coming in five months after we will have asked the voters to increase the sales tax by half-a-cent for roads and public safety,” Kozachik said, adding that several other fee and tax increases could make their way on the November ballot, including state propositions for pre-K education and teacher increments and a possible 4 percent sewer rate fee by the Pima County Board of Supervisors.

Kozachik said that there are other ways for the zoo to get capital improvement funding, and he’s in the process of discussing a nonresidential rate for admission with City Manager Mike Ortega, with all the added money going toward capital improvements.

The group wants to add a tenth of a cent to the city’s existing sales tax.

Similarly, Tucson Mayor Jonathan Rothschild expressed reservations about the zoo’s proposal.

“The city’s priorities are fixing our roads and having 21st-century police and fire departments. We have also been planning for investment in our city park system overall, of which the zoo is one component,” Rothschild said in an email statement. “Going forward in a piecemeal manner is likely to be detrimental to funding our park system overall.”

Rothschild is meeting with campaign organizers Friday, and said that he plans to discourage them from going forward with the separate zoo tax, but to instead coordinate with the city in working to improve the parks system as a whole.

“We’re talking about adding a penny to a large cheese pizza,” campaign chairman Ball said. “Almost everybody can afford to do that, and in the long run, the community will benefit significantly from having a zoo that’s world class and will provide the educational opportunities and have a quality of life and enrichment for our animals that’s going to be far better than what we have right now.”

For the initiative to make the November ballot, the group must file the required petitions with the City Clerk’s Office by 5 p.m. on July 6, according to the Tucson city clerk’s website.

The campaign will rely on volunteers rather than paid signature gatherers, Kluge said. Interested parties should call 477-2983 or email info@futureofyourzoo.com.

Contact reporter Caitlin Schmidt at cschmidt@tucson.com or 573-4191. Twitter: @caitlinschmidt