Mayor’s Office and Sheriff’s Office officials announced Thursday that two property taxes — 1.5 mills and another 0.5 mill — are necessary in addition to a quarter-penny sales tax to pay for the mayor’s proposed public safety plan.

Mayor-President Kip Holden’s administration released the construction details and cost estimates for seven public safety projects Wednesday, but the quarter-penny sales tax would cover only the construction costs of $335 million. The smaller half-mill property tax would go toward operating the mental health facility dubbed the “Restoration Center,” while the more expensive 1.5-mill property tax would cover the costs of running a new and larger prison.

In addition to the prison and mental health center, Holden is proposing a new juvenile services facility; a district attorney and public defender building with a secure prisoner entryway; police headquarters renovations; and sheriff’s civil division renovations. William Daniel, Holden’s chief administrative officer, said no other property taxes would be necessary to run the other proposed projects.

As for the 0.5-mill property tax, Assessor Brian Wilson said someone with a $250,000 homestead-exempt home would pay an extra $8.75 a year in property taxes; someone with a $100,000 homestead-exempt home would pay an extra $1.25 a year.

Daniel said he expects the extra property tax money to generate $1.8 million a year for the mental health center.

If people pay the combined 0.5-mill property tax for the mental health center and the 1.5 mills for the prison, their property taxes would rise by 2 mills. Bills for homestead-exempt property owners with $250,000 houses would increase by an extra $35 total, while those with a $100,000 house would pay an extra $3.75 year.

The quarter-penny sales tax would span the next 25 years. Food for home consumption and prescription drugs would not be taxed. People shopping in Baton Rouge currently pay a 9 percent sales tax, which is a combination of city-parish and state taxes.

“Everything will be built with the quarter-penny sales tax; any millage will only be used on the operation of the facility,” Daniel said.

The Metro Council will vote Wednesday whether to add the tax plan to the May 2 ballot.

“We are at a critical crossroads,” Sheriff Sid Gautreaux said in an email. “This bond issue is an integrated approach to solving our crime problems while averting the threat of (a) consent decree by the federal government.”

Holden has unsuccessfully tried three times to convince Baton Rouge voters to pay higher sales and property taxes for new buildings, prisons and other additions to the city. His past plans were more expensive by hundreds of millions of dollars, and Holden said Wednesday that they intentionally sized down this proposal to the necessary priorities.

The Baton Rouge Area Foundation is heavily involved in the creation of the $16 million mental health Restoration Center. In addition to the sales tax money to build it and the property tax money to operate it, project manager Patricia Calfee said, they will seek federal grants, Medicaid money, state funding and other sources.

“We’re involved because currently there is no pathway for people with a mental health issue other than the criminal justice system,” Calfee said.

Holden’s administration has hailed the tax plan as a public safety measure and said it reinforces Holden’s strong belief in improving public safety in the city.

Advocate staff writer Ben Wallace contributed to this report.