Blue Lake / Warwar

Blue Lake / Warwar
Location	Mount Gambier, South Australia
Coordinates	37°50′48″S 140°46′41″E
Type	Crater Lake
Basin countries	Australia
Average depth	70 m

The Blue Lake (37°50′48″S 140°46′41″E) in Mount Gambier is a large lake located in an extinct volcanic caldera. It is known as Waawor in the local Aboriginal language.

During December to March, the lake turns to a vibrant cobalt blue colour, returning to a colder steel grey colour for April to November. The exact cause of this phenomenon is still a matter of conjecture but it is generally considered likely that it revolves around the warming of the surface layers of the lake during the summer months to around 20 degrees C, causing calcium carbonate to precipitate out of solution and enabling Micro-crystallites of calcium carbonate to form. This results in scatter of the blue wavelength of sunlight. The movement of planktonic life-forms within the lake during the seasons and during the day may also play a part in the visibility changes.

The Blue Lake supplies the town with drinking water, providing approximately 3,600 ML per year from its 36,000 ML store. Its average depth is 70 m.

Gallery

• 
  The Blue Lake in early March.
• 
  The Blue Lake in early March.
• 
  The Blue Lake in early March.
• 
  Approximately 4 metres above the lake's surface.
• 
  Panorama of the Blue Lake in mid-December.