An Australian man has been left with severe spinal injuries after a freak accident involving a makeshift waterslide.

The 20-year-old and a group of friends had made their own 15-metre waterslide in a creek near a Murphys Creek property, west of Brisbane, on Christmas Eve.

The man slid down the slide at around 10.40pm (AEST), but he skimmed across the creek and hit the bank on the other side.

He was treated at the scene by paramedics and airlifted to hospital in a serious condition with severe spinal injuries.