Fitzroy River flows for 733 kilometres from the King Leopold and Mueller Ranges into King Sound south of Derby, and has a catchment area of 93,829 square kilometres. In full flood the flow rate down the 15 km-wide flood plain at Fitzroy Crossing is estimated to be 23,000 cubic metres per second, which in six hours this volume of water could fill Sydney Harbour   

The major floods since 1957 when levels were recorded are:
1983  22.37m
1984  22.28m
1986  22.09m
1991  22.39m
1993  24.38m
1996  20.40m
1997  19.80m
1999  19.00m
2000  22.05m
2001  21.85m
2002  22.66m
2007  19.20m
2009  19.90m
2011  22.69m