Plaquemines Parish residents will vote Saturday on a half-cent sales tax increase that would provide raises for teachers and other parish school employees.

The proposed tax, projected to raise $4.75 million in the next year, would be levied and collected “in perpetuity,” meaning it would be permanent if approved this year.

The board unanimously approved a measure to put the tax on the October ballot during a June 1 meeting. If voters approve, teachers would get an across-the-board raise of $6,500 a year, an increase, on average, of 11 percent to 12 percent.

Other employees, such as teachers’ aides, bus drivers, custodians and professional assistants, would get a similar boost in pay.

Education officials said getting the tax hike will be critical. The district recently became one of the few A-rated districts in Louisiana. But the parish has had a problem retaining teachers for the past couple of years, officials said.

Seventeen teachers have left Belle Chasse High School in the past year alone, according to parish schools Superintendent Denis Rousselle.

Ronald White, the finance director for the Plaquemines Parish School Board, partially attributes the attrition to location. “It’s a little harder to attract the best teachers to the parish because of geography,” White said. “The parish is a little isolated.”

For Rousselle, it boils down to paychecks. To retain quality teachers, the district has to pay accordingly, he said.

“These days, it’s a battle to get good, powerful teachers, and you have to pay teachers what they’re worth,” Rousselle said. “There’s a shortage throughout the state.”

Plaquemines’ average teacher salary — $45,611 a year — ranked seventh among the seven parishes in the New Orleans metro area during the 2013-2014 school year, a chart provided by the district shows.

In Orleans, which ranks in the middle of the group, teachers make an average of $51,212.

Even with a $5,000 increase in teacher salaries, Plaquemines still would rank only fifth.

The average public school teacher salary in Louisiana in the 2013-14 school year was $49,067, according to the National Education Association.

With a half-cent increase in the sales tax bringing the total to 8 percent, Plaquemines still would have the lowest parishwide tax rate compared with its neighbors, district officials said. St. Tammany has the highest rate at 9.75 percent.

If voters approve the sales tax proposal, the School Board will make the new pay raises retroactive to July 1, the beginning of the fiscal year.

The board would give employees a lump-sum payment in December for the additional salary that would be owed them since July, according to a brochure on the proposal, and would raise regular paychecks in January.

“We’re doing well, but we could do much better,” Rousselle said. “High teacher turnover rates — it’s not good. You need to pay them for what they’re worth.”