In May 2011, the Wentworth Group of Concerned Scientists withdrew its support for the Basin Plan, and described the process as seriously flawed and a waste of taxpayers' money. The Wentworth Group said they could not support the Plan which they believed would cost billions and claimed that it would not fix the problems in the river system. The Wentworth Group wanted a minimum 4,000 gigalitres of water returned to the river system but the Group believed that it would not happen under the draft plan.