Tucson voters approved two propositions — one narrowly — that will increase the city's sales tax to pay for upgrades at Reid Park Zoo, officials said Thursday after counting 10,000 ballots from Tuesday's election.

The sales tax hike was in danger of not passing because one of the two propositions that needed to be approved was failing after most of the votes were counted Tuesday night. The other proposition held a comfortable lead.

With nearly all of the ballots now counted, Proposition 203, which dealt with increasing the sales tax by one-tenth of a percent for 10 years, narrowly passed by 605 votes.  The accompanying measure, Prop. 202, which would change the city charter to allow for the tax increase, passed 53 to 47 percent.

County officials estimated there are less than 250 ballots that still need to be counted, primarily related to signatures not matching, but that is not enough to change the outcome.

Revenue from the sales-tax increase could provide between $8 million and $10 million in funding annually to the 50-year-old zoo over the next decade.

The new revenues would go to infrastructure upgrades inside the zoo and expansions to several existing animal habitats.