Medieval Warm Period
Although it is the driest of the three main rivers of the Lake Eyre Basin, there is evidence that the Georgina has, in the past, actually reached the lake more frequently than either the Diamantina or Cooper. Some wave built shingle terraces suggest that during the Medieval Warm Period Lake Eyre held permanent water. Large increases since the late 1960s in rainfall over the Northern Territory and pastoral areas of South and Western Australia that have "not" been duplicated over Queensland do suggest an enhanced greenhouse effect in the Medieval Warm Period may have caused the Georgina to regularly fill Lake Eyre. However, far too little evidence exists for any certainty of this.