Charleston International Airport (copy)

Passengers arriving at Charleston International Airport make their way under the dome. Brad Nettles/Staff

Charleston International will surpass 5 million passengers for the first time this year, boosting coffers by 11 percent as travelers spend more on concessions, parking and rental cars, according to new financial projections.

The airport's proposed budget calls for roughly $75 million in revenue over the current $68 million. Last year, 4.47 million passengers flew in and out of Charleston.

As more travelers choose to fly out of the state's busiest airport and more airlines offer more destinations, the Charleston County Aviation Authority, which owns and operates the terminal, collects more revenue from the $4.50 passenger facility charge tacked onto ticket costs.

Next year, the fee will bring in more than $9.8 million, a 13 percent increase. The surcharge, capped by the federal government, helps to support terminal upgrades.

The growing number of passengers also are projected to spend more on meals and gift items, further swelling airport income. Parking fees alone are expected to generate $14.25 million, up more than $1 million over the current budget year.

"We are the beneficiaries of growth," said airport finance director Doug Boston.

The spending layout also calls for fewer employees, an average 3 percent raise based on performance and a 9 percent jump in health insurance costs.

The airport's employee count will drop by five to 203 because of attrition and reallocation of duties.

The downside to more people flying in and out of Charleston is that the terminal has to continue to expand, and that requires money.

"We don't have taxpayers," airport CEO Paul Campbell said. "We have to take care of our own revenue. We have to manage our own finances. ... And if we don't have cash, we can't plan for the future."

The airport is currently constructing a nearly $90 million, five-level parking garage and is still paying off the debt on the $200 million terminal overhaul that was completed in 2016. The debt from those two projects next year tallies up to more than $11 million.

On the other hand, higher revenue and financial management will bring in nearly $1.75 million in interest income, or about $1.3 million more than now.

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Terminal officials will soon embark on expanding the airline check-in stations by adding onto the building where airport personnel currently park. Next year's budget will also include money for design work on a new wing, or concourse, the airport believes it will need by 2023.

Board member Henry Fishburne suggested the airport spend conservatively over the next few years to help pay for a slew of new projects.

"I feel like Scrooge," Fishburne said. "We are obviously successful, but we are going to spend money on several capital improvements over the next few years. The more prudent we are now the less we will have to borrow money."

Fishburne, a former Charleston City Council member, added, "It's easy to spend money, but it's harder to raise taxes or fees to pay for something. We have several big projects on the way."

His comments came during a discussion over offering a percentage increase in pay for the airport's workers.

Airport board members on the finance committee also agreed to a salary study on all employees after board member Jerome Heyward suggested the pay for some longtime workers is below par.

The authority will consider final approval of next year's budget during its monthly meeting in June.

Reach Warren L. Wise at 843-937-5524. Follow him on Twitter @warrenlancewise.