IMF is set to fund a potentially massive class action against the Queensland Government seeking damages for residents and businesses affected by the 2011 floods in Brisbane.

The announcement follows investigations by law firm Maurice Blackburn, which it says found failings in the operation of the Wivenhoe Dam, which led to properties along the Brisbane River becoming inundated.

IMF said investigations by "independent US experts" found Wivenhoe dam operators had failed to use rainfall forecasts in making decisions about operating strategies and failed to preserve a reasonable amount of Wivenhoe's storage capacity to provide optimum protection of urbanised areas.

"Based on these investigations, IMF has formed an opinion that material flooding of a large number of properties down river from the Wivenhoe dam would not have occurred had Wivenhoe been operated during the flood event to the standard expected of a reasonably competent dam operator in all of the circumstances," the company said in a statement.

IMF said it would seek to make flood victims, who suffered loss and damage caused by the operation of Wivenhoe, aware of their right to claim.

The company said it expected to conclude the victim enrolment process for the action in April.

About 20,000 homes and businesses were inundated when the Brisbane River peaked on January 13, 2011, following days of heavy rainfall across south eastern Queensland.

The Queensland Government was criticised at the time over its handling of water releases from the Wivenhoe Dam.