County-run JWA has to operate under an annual cap of 10.8 million passengers to limit impacts on surrounding communities. Each year, the supervisors divide available departures among air carriers.
While Southwest is adding flights, other carriers are dropping them. U.S. Airways, United Airlines, WestJet and Mesa Air are all scaling back their departures. Those four airlines would relinquish their rights to about six flights per day.
Airport spokeswoman Jenny Wedge said that in case the carriers are approaching the 10.8 million passenger mark, the airport would be able to withdraw some approved flights.
This year, Southwest has approval for 47 flights per day, and next year it will be allowed 49 flights per day, starting in June. The carrier would represent about 40% of the total seats allowed in 2012.
"It's kind of being bullish on the future," Southwest spokesman Brad Hawkins said, adding that rising fuel costs could change plans. "Orange County is definitely a keystone in our Southern California strategy."
Hawkins said he couldn't disclose if the company was adding new routes, but in May Southwest acquired AirTran Airways, which flies to additional markets.
Also in the JWA capacity plan is a new carrier, Compass Airlines, which plans to operate Delta Connection's commuter flights.
In other airport news, crews are finishing the Southwest and Frontier Airlines ticketing counters, among other interior improvements in Terminal C.