A series of Brisbane City Council catchment studies has reassessed the flood risk to 6200 properties, and while more than 3700 were found to be better off, it was bad news for almost 750 Brisbane property owners.

The council has completed five new creek catchment studies, which Lord Mayor Graham Quirk said provided the most comprehensive flood risk information ever available.

Brisbane City Council has revised its flood data, affecting thousands of homes. Credit:Bradley Kanaris

Cr Quirk said about 6200 property owners would receive the updated information next month, ahead of the summer storm season.

"Newer technology allows us to more accurately and comprehensively predict the impact of rainfall within creek catchments and how creek flooding will impact surrounding areas," he said.