Freshwater Lakes and Rare Forests

Surprisingly, 40 freshwater lakes are captured in the hollows of sand dunes across the island. Some of these bodies of water are known as perched lakes because they sit in large depressions on top of towering sand dunes. What prevents the water from seeping away? An organic liner, or peat caulking, in the form of partially decomposed leaves, bark, and branches.

The island also has window lakes, which form when depressions in the sand dip below the level of the groundwater table. Fresh water seeps into the hollows, creating crystal-clear, sand-filtered pools that are, in effect, windows in the water table.

The island’s lakes are replenished by 60 inches [150 cm] of rain a year. Water not trapped by lakes or soaked up by sand forms creeks that run into the sea. One stream is estimated to empty well over a million gallons [5 million L] of water an hour into the Pacific Ocean.

Forty freshwater lakes, including perched and window lakes, dot Fraser Island