The Wimmera has an abundance and diversity of wetlands and related natural values. There are over 3,000 wetlands in the region. This equates to roughly 25% of Victoria’s individual non-flowing (not linked to rivers or streams) wetlands. Over 90% of the Wimmera’s wetlands are on private land, so private landholders play a vital role in their management.

Most of the Wimmera’s wetlands contain significant cultural value. They provide significant resources and spiritual value for First Nations people. This ongoing connection is still reflected today. For example, a study in 2017 of Ross Lakes near Ngalpakatia/Ngelpagutya (Lake Albacutya) reidentified two middens and nine scar trees. It also discovered 32 new scarred trees, a rare carved tree, clay balls and middens. The report concluded that Ross Lakes was an important meeting place. It is clear by the age of some of the sites that this connection has remained.

Wetlands are highly diverse in terms of their hydrology and salinity. The Wimmera includes a range of fresh, shallow, seasonal and periodically inundated wetlands, more permanent deep lakes and shallow and deeper groundwater-fed saline wetlands (Figure 6). This contributes to high wetland biodiversity, with the different categories  of wetland supporting a highly diverse mix of plant, bird, macroinvertebrate and other wetland species.

Figure 6: Number and percentage of wetlands greater than one hectare in size in each wetland category in the Wimmera.
Periodically Inundated Fresh (2,748 - 88.7%), Periodically Inundated Saline (234 - 7.6%), Unknown Water Regime Fresh (56, 1.8%), Periodically Inundated Unknown Salinity (40 - 1.3%), Permanent Fresh (15 - 0.5%), Unknown Water and Salinity Regime (3 - 0.1%), Permanent Saline (2 -0.06%)

Figure 6: Number and percentage of wetlands greater than one hectare in size in each wetland category in the Wimmera

Most of the Wimmera’s wetlands are in the Millicent Coast Basin and dry up periodically. Only 1.5% of the region’s wetlands are categorised as permanent.(8)

The Wimmera is home to many Seasonally Herbaceous Wetlands (Freshwater) of the Temperate Lowland Plains which are listed as a critically endangered ecological community under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).

Ngalpakatia/Ngelpagutya (Lake Albacutya) is recognised as an internationally significant wetland via the Ramsar Convention. Gurru (Lake Hindmarsh) is Victoria’s largest freshwater lake and is listed as a nationally significant wetland. Both receive water from the Barringgi Gadyin (Wimmera River), via Outlet Creek for Ngalpakatia/Ngelpagutya (Lake Albacutya). The episodic nature of flows into these terminal lakes means that they can be empty for many years before floodwaters fill them for at least a couple of years, watering fringe vegetation and providing a haven for tens of thousands of migratory water birds. There are also several other downstream terminal lakes that rely on Ngalpakatia/ Ngelpagutya (Lake Albacutya) filling that they have not received water for at least 40 years.

Others such as Lakes Fyans, Bellfield, Wartook, Taylors Lake and Lake Lonsdale are important water storages and can provide some environmental values as well as important water resources for the region and beyond. For example, at low water levels Lake Lonsdale supports abundant waterbirds who enjoy the shallow water habitat.

The Wimmera’s wetlands support many plants and animals of international and national significance. Migratory birds are known to frequent the region to breed and the endangered regent parrot (Polytelis anthopeplus) inhabits the surrounds of Lakes Albacutya and Hindmarsh. Wetlands also play an important role in supporting waterbirds such as the plumed whistling duck (Dendrocygna eytoni) when there is drought in other parts of the country. They also support local bird migrations from the Victorian Coast to the Murray River and are home to endangered plants such as ridged water milfoil (Myriophyllum porcatum) and spiny lignum (Duma horrida).

Some wetlands, such as Pink Lake, Natimuk Lake, Oliver’s Lake and White Lake, are considered to be ecologically of national significance.(9)

Many of the region’s wetlands provide significant recreation opportunities, contributing economic and health benefits to the region when they contain water. Lake Fyans and Lake Wallace alone generate around $2.5 million and $1 million per year respectively for their local community through the events, tourism and recreation opportunities they provide.

Wetlands can be grouped into sub-regions or wetland systems based on similar geographic characteristics and management issues (Figure 7). The wetland systems and their key attributes include:

  1. Terminal lakes of the Barringgi Gadyin (Wimmera River)
    • Including internationally significant Ngalpakatia/ Ngelpagutya (Lake Albacutya) Ramsar site and nationally significant Gurru (Lake Hindmarsh)
  2. Natimuk-Douglas saline wetland system
    • Saline and freshwater lakes of global bird conservation importance
    • Eleven wetlands are nationally important
  3. South–west Wimmera wetland system
    • Major wetland complex, supporting high biodiversity
    • EPBC Act listed Seasonal Herbaceous Wetlands (freshwater) of the Temperate Lowland Plains
  4. Northern Wimmera Plains wetlands
    • Scattered wetlands in an intensively cropped landscape
    • Pink Lake is nationally important
  5. Wetlands of the Upper Barringgi Gadyin (Wimmera River) catchment
    • Scattered wetlands, regionally important water supply storages and recreational lakes
Map showing Wetlands and major wetland systems in the Wimmera

Figure 7: Wetlands and major wetland systems in the Wimmera