Australian Wetlands Database

Ramsar wetlands

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Western District Lakes

Overview

Key facts and figures:

Date of listing:

15 December 1982

Lake Purrumbete lies in a volcanic crater and is fed largely by underground water (1980), Photo: Andrew Corrick

Australian Ramsar site number:

20

Criteria: 

1, 2, 4, 5, 6

State/Territory:

Victoria

Area:

32,898 hectares

Drainage Division or IMCRA  region:

Southeast Coast

Wetland type: 

  • O - Permanent freshwater lakes (over 8 ha); includes large oxbow lakes
  • Q - Permanent saline/brackish/alkaline lakes
  • R - Seasonal/intermittent saline/brackish/alkaline lakes and flats
  • Tp - Permanent freshwater marshes/pools; ponds (below 8 ha), marshes and swamps on inorganic soils; with emergent vegetation water-logged for at least most of the growing season

Key features of the site:

The Western District Lakes Ramsar site is located within the western volcanic plains region of Victoria, near the township of Colac. It lies within the landlocked Lake Corangamite catchment and is comprised of nine separate lakes.

The lakes vary in size, depth and salinity, depending on their method of formation, catchment area and outlet. Lake Corangamite is the largest, covering approximately 25 000 hectares. The only significant river in the region, the Woady Yallock River, drains into this lake.

The Ramsar site is roughly equivalent to the high-water mark of the nine lakes and vegetation within the site is therefore limited. Approximately 10-20% of the lake margins are vegetated, mostly with saltmarsh communities. A total of five submerged aquatic plant species have been recorded. Two nationally threatened species, the salt-lake tussock-grass (Poa sallacustris) and spiny peppercress (Lepidium aschersonii) occur within the Ramsar site.

The Ramsar site provides habitat for approximately 70 waterbird species, 20 of which are listed under international migratory species treaties and 11 of which breed within the Ramsar site. Some species congregate there in large numbers, including the Australian shelduck, chestnut teal, Australasian shoveler, Eurasian coot and banded stilt.

Six native species of fish have been recorded within the lakes of the Ramsar site. Of the invertebrates recorded, molluscs dominate most of the saline and mesosaline lakes whilst Lake Colongulac is dominated by oligochaetes.

Hydrology is variable across the site. Some of the lakes are permanent whilst others are seasonal or intermittent. All are connected to saline, surficial groundwater and all except Lakes Beeac and Cundare are groundwater flow-through lakes. Most of the water is received through direct rainfall and lost via evaporation. All lakes are highly turbid and have high nutrient levels.

The region is spiritually and culturally significant for the Djargurd Wurrung and Gulidjan Indigenous groups. There are several important archaeological sites in the Ramsar site, which was particularly significant for the provision of food.

Justification of the listing criteria:

The Western District Lakes Ramsar site met five of the nine Ramsar criteria at the time of listing:

Criterion 1: Lake Corangamite was the largest inland permanent saline lake in Australia and a good example of a permanent saline lake within the bioregion.

Criterion 2: The site supported two flora species listed as threatened under the national Environment Protection and Biodiversity Conservation Act 1999 - salt-lake tussock-grass and spiny peppercress.

Criterion 4: The site provided a number of functions for waterbirds including supporting species during migration, breeding and moulting and providing a drought refuge.

Criterion 5: While data are limited, there is evidence that the site regularly supported more than 20 000 waterbirds.

Criterion 6: The site has supported more than one percent of the populations of 12 species, including regularly supporting more than one percent of the populations of the Australian shelduck, chestnut teal, Australasian shoveler and Eurasian coot.

Please see the More Information page for additional information on this Ramsar site and access to the Ramsar Information sheets and other associated site documents.