Supporters of the Pima County bonds said they were shocked that voters appear poised to reject all seven questions in the massive bond plan.
"I was stunned, stunned," Larry Hecker, chairman of the Yes on Pima County Bonds campaign said Tuesday night.
With all of the early ballots counted, none of the seven questions has more than 47 percent voting in favor.
Results from polling places have not been tabulated.
County voters are deciding the fate of $815 million in bond projects.
The bond questions cover projects to build parks, roads, flood controls and tourism amenities among the 99 individual projects.
"I think the public was knowledgeable," said Joe Boogaart, spokesman for Taxpayers Against Pima Bonds. "Our message got across."
The seven questions in Tuesday's package would add 39 cents to the county's secondary property tax over the 27-year payoff schedule. The increases would be staggered over the years, as the county pays down existing debt, with the total secondary rate not exceeding the county's self-imposed limit of 81.5 cents per $100 of assessed value.
The current secondary rate is 70 cents.
Homeowners with a home valued at the region's $152,000 average would pay about $59 per year in secondary taxes to pay off the bonds.
Voters in recent elections have supported other bond proposals.
County voters approved a $22 million plan to expand the animal care center in 2014, and in November 2012, city voters agreed to a $100 million road bond plan.
