A $4.6 million parking lot expansion project at Manhattan Regional Airport should help ease the airport’s congestion, but money for the project will come from travelers who will pay up to $5 per day for parking.

The Manhattan City Commission on Tuesday unanimously approved the project and the $5 maximum daily rate, but airport officials won’t implement the fees until the expansion is complete, likely in November 2020.

Airport staffers also will work on a parking lot management plan to consider items such as differing rates for hourly parking and a possible rewards program for frequent users.

The parking plan also would likely offer a grace period for people who are only dropping off or picking up travelers at the airport.

For the past several years, officials have looked for ways to relieve some of the airport’s parking congestion. The airport’s lots are typically filled during peak travel times such as the Christmas holiday season. A 2018 parking lot expansion added 86 spaces to the airport’s lot, bringing the total up to 669. The project would further increase the total to about 900 spots, airport director Jesse Romo said.

Last year, the average parking lot occupancy was 63%, with travelers parking an average of 2.87 days at the airport. With the new parking fee, a study from Walker Consultants shows leisure travel demand for parking could drop by as much as 20%, and business travel demand by as much as 5%.

Business travelers make up 60% of airport business.

Romo told the commission that airport staff found that a $5 daily parking fee should be enough to cover $615,000 in expected yearly debt service costs over the life of a 10-year bond for the project.

The airport would also establish a reserve fund for future maintenance expenses using revenue from the fee.

Project costs include $3.2 million to Shilling Construction Co. for actual construction of the project and $209,000 to Olsson Associates for construction administration services. The city has already spent $806,000 on related-construction expenses and other administrative costs.