Reedy Lake

Reedy Lake, historically also known as Lake Reedy, is a shallow 5.5-square-kilometre (2.1 sq mi) intermittent freshwater lake or swamp on the lower reaches of the Barwon River, on the Bellarine Peninsula southeast of Geelong in the Australian state of Victoria.

Reedy Lake, historically also known as Lake Reedy, is a shallow 5.5-square-kilometre (2.1 sq mi) intermittent freshwater lake or swamp on the lower reaches of the Barwon River, on the Bellarine Peninsula southeast of Geelong in the Australian state of Victoria.

Six thousand years ago Reedy Lake was part of a large marine bay.With a subsequent change in relative sea level it was cut off from the sea by a barrier of sand dunes, and its bed covered by a layer of alluvial clay deposited by the Barwon River.Before European settlement of the area in the early 19th century the lake was an ephemeral wetland that became saline in summer from the seepage of salty ground-water and occasional exceptionally high tides.In winter it usually became fresh, as river floods flushed out the saline water.The first barrier across the Barwon was built in 1838 to provide fresh water for Geelong.In 1899 a second barrier, known as the 'lower breakwater' was built further downstream on the river at the southern boundary of Reedy Lake, making it a predominantly freshwater wetland, with an extensive cover of vegetation, that supported diverse populations of waterbirds and other aquatic wildlife.By the 1930s its natural values were becoming appreciated and, in 1935, it was temporarily reserved for "public purposes".Later it was protected permanently and its level of protection upgraded to that of game reserve.During the 1950s, 1960s and 1970s further works were carried out and refinements added, such as inlet pipes from the river above the lower breakwater and an outlet channel with a flow regulator, to maintain and control water levels in the lake.In the early 1990s the lake began to suffer degradation as the more permanent and deeper water levels allowed a large population of the introduced common carp to build up.The feeding behaviour of the carp undermined the reedbeds and increased water turbidity, leading to the death of submerged plants, decreased oxygen levels and the decline of small aquatic wildlife.This was remedied in 1996-1997 by drying out the lake to kill the carp before allowing it to fill again.Since then water levels have been closely managed, with some seasonal drying in summer, to limit carp numbers and to maintain areas of open water as waterbird habitat.