Has it ever flooded at the cul de sac end of Bilsen Rd?

Parts of Downfall Creek certainly flooded in January 2012. It was reported by Council that an area between Bilsen and Newman Roads was flooded at this time. I can't confirm any impact on property in that area at this time, but can update you after maybe talking to some locals. In the meantime you might like to have a look at the Brisbane Interactive Flood Awareness Maps (http://floodinformation.brisbane.qld.gov.au/fio/).