THE Mary River is the beating heart of the Gympie region, originating in the Conondale Range and following a winding course, mainly north, for 305km before emptying into the Great Sandy Strait, the narrow stretch of ocean between Fraser Island and the mainland.
The river is navigable to Maryborough, 37km from its mouth.
Every now and then, the Mary breaches her vertical banks and sends her muddy floodwaters into the Gympie CBD and many properties that line her throughout the region.
February floods have been common through history, though plenty of floods have also occurred in almost every other month of the year.
In February, 1999, the region received 478mm of rain and the Mary reached 21.95m.