Charleston International Airport and Air Force Base will be down to one runway for up to a year.

On June 18, reconstruction will begin on the main 9,000-foot runway, which will be closed for nine to 12 months to all air traffic, the Air Force announced Tuesday.

DWG and Associates of Colorado Springs, Colo., will perform the work on the more than $40 million project.

The Air Force owns the runways at the airport, which serve both the 437th Airlift Wing and Charleston International. The air base serves the nation’s largest fleet of C-17 cargo planes, 54 semis in the sky that transport just about everything for the military around the globe.

During construction, all 128 commercial flights per day and about 25 Air Force flights per day will be diverted to the secondary, 7,000-foot runway that underwent a major face-lift in 2009 and early 2010.

In addition to commercial carriers and military planes, Boeing Co. uses the North Charleston airfield to deliver locally made 787 Dreamliner parts to the Seattle area on a specially modified fleet of 747 cargo jets. It also uses the airport to fly its locally made new 787 Dreamliner.

Portions of the runway were built in the 1940s, and it is nearing the end of its lifespan, according to Air Force spokeswoman Michaela Judge. Cracks have routinely snaked their way across the 200-foot-wide stretch of concrete, and the Air Force has done spot repairs.

“Instead of spending additional time and resources in the continual repair of joints, lights and the runway surface itself, the Air Force has applied sound asset management principles and decided to reinvest funds into the runway to bring it up to current standards,” Judge said. “This will help ensure safe flight operations for both military and commercial aircraft.”

Eighteen inches of concrete will be ripped out and replaced on about 8,000 feet of the landing and take-off strip, and the runway’s width will be reduced to 150 feet, which is the Air Mobility Command’s Standard size.

The work is expected to have a minimal impact on air traffic, according to airport officials.

“The (Charleston County Aviation) authority and the airlines have been working with the Air Force for about a year in anticipation of this project, and we expect everything to run smoothly,” airport spokeswoman Becky Beaman said.

If any aircraft are affected, it most likely would be regional 50-seat jets, Airports Director Sue Stevens said.

They might have to carry a little less fuel or passengers, but it depends on temperature, load and other variables, she said.

Because the Air Force owns the runways, the federal government will be picking up the tab.

“That’s a big deal,” Stevens, the airports director, said. “If we were in Columbia or Greenville, we would have to pay for it ourselves. We are fortunate to have the Air Force here.”

Reach Warren L. Wise at 937-5524 or twitter.com/warrenlancewise.