Fly Corporate's air services out of the Shellharbour Airport are operating, the company has said this morning.
The Shellharbour City Council issued a statement this morning saying the airport would be closed, but Fly Corporate said it was able to resume services under some delay.
The issue has been caused by excess water on the runway.
The Fly Corporate flight to Melbourne this morning departed at 8.05 am, later than the scheduled 6.15 am departure.
The Wollongong to Brisbane flight due to depart at 9.05 am will be delayed until later this morning.
Fly Corporate said it is liaising with customers directly.
"It's great to have the rain, but it's been a trying situation," a spokesman said this morning.