Wimmera system

Latest information about where, when and why environmental water may be delivered to the Wimmera system and the environmental objectives being targeted is available in this year’s seasonal watering plan.

The seasonal watering plan also contains information about how environmental flows could support cultural, social, recreational and economic values in the Wimmera system.

Watering data for the Wimmera system and the wider western region is updated quarterly. Visit current watering releases to find out more.

To find out the current environmental water entitlements held by the VEWH in the Wimmera system visit our water holdings.

Waterway manager

Glenelg Hopkins Catchment Management Authority

Storage manager

Grampians Wimmera Mallee Water

Environmental Water Holders

Victorian Environmental Water Holder
Commonwealth Environmental Water Holder

Traditional Owners

Barengi Gadjin Land Council (BGLC) has a Recognition and Settlement Agreement with the Victorian Government and is a statutory authority for the management of Aboriginal heritage values and culture, under the Victorian Aboriginal Heritage Act 2006. Traditional Owners represented by BGLC hold native title (the Wotjobaluk, Jaadwa, Jadawadjali, Wergaia and Jupagulk peoples).

System overview

Barringgi Gadyin (Wimmera River) rises in the Pyrenees Ranges near Elmhurst and flows through Horsham, Dimboola and Jeparit before terminating at Lake Hindmarsh, which is Victoria’s largest freshwater lake and the first of a series of terminal lakes. The Wimmera River receives flows from several regulated tributaries, including the MacKenzie River, Mount William Creek and Burnt Creek. These tributaries, plus Bungalally Creek and the Wimmera River below Mount William Creek, can receive water for the environment. In exceptionally wet periods, Lake Hindmarsh will overflow into Outlet Creek and then to Lake Albacutya, an internationally recognised Ramsar-listed wetland. Many wetlands beyond Lake Albacutya have not filled with water for decades.

Water in the Wimmera system is stored in three on-stream reservoirs (Lake Wartook on the MacKenzie River, Lake Lonsdale on Mount William Creek and Lake Bellfield on Fyans Creek) and in several off-stream storages (Taylors Lake, Lake Fyans and Toolondo Reservoir). A channel system enables water to be moved between storages. Water can also be transferred from Rocklands Reservoir in the Glenelg system to the Wimmera system via the Rocklands-Toolondo Channel and from Moora Moora Reservoir via the Moora Channel. The connected storages and channels are collectively called the Wimmera-Mallee System Headworks. Water harvested in the system headworks is used for town, stock and domestic supply throughout the Wimmera catchment and parts of the Avoca, Hopkins, Loddon, Glenelg and Mallee catchments. Passing flows are provided to the Wimmera River and lower Mount William and Fyans creeks.

Priority reaches in the Wimmera system that can receive water for the environment are Wimmera River reaches 3 and 4, MacKenzie River reaches 2 and 3, upper and lower Mount William Creek, upper and lower Burnt Creek and Bungalally Creek.

Yarriambiack Creek is a distributary of the upper Wimmera River that would have naturally received a flow during high-flow or flood events. Lower reaches of the Wimmera River have priority for environmental water, which means no water is diverted for environmental watering to this creek. Grampians Wimmera Mallee Water provides recreational entitlements via the Wimmera-Mallee Pipeline to the creek at the Warracknabeal, Brim and Beulah weir pools.

Downstream of Jeparit, the Wimmera River reaches the terminal lakes, including Lake Hindmarsh, a wetland of national significance and Lake Albacutya, recognised internationally under the Ramsar Convention. These lakes do not usually receive environmental water but rely mainly on passing flows and/or unregulated flows to provide suitable inundation to achieve environmental outcomes. However, in a wet year, regulated releases are of some value for raising the levels of terminal lakes and improving environmental outcomes.

Dock Lake, near Horsham, would have naturally filled via spills from nearby Green Lake when there was significant run-off from the northern edge of the Grampians. In the 1930s, Dock Lake was modified to allow it to be used as a water storage for irrigation supply in the Wimmera-Mallee system. Dock Lake was removed from the supply system after the Wimmera-Mallee Pipeline was completed in 2010. Water can be delivered to Dock Lake from Green Lake via a gravity-fed channel when there is sufficient water in Green Lake.

Ranch Billabong, near Dimboola, is an anabranch of the Wimmera River at Dimboola. It is on land managed by Barengi Gadjin Land Council Aboriginal Corporation. The anabranch was disconnected from the Wimmera River by changes to a road that traverses land between the river and the billabong. Restoring elements of the natural water regime at Ranch Billabong aims to improve habitat for native animal and plant communities and is an important outcome for Traditional Owners.

Environmental values

The Wimmera River supports abundant native fish populations, including one of Victoria’s few self-sustaining populations of freshwater catfish. The Wimmera River also supports native waterbird, turtle, frog and rakali (water rat) populations.

The MacKenzie River contains the only confirmed remaining platypus population in the Wimmera system and supports locally important populations of native fish, including river blackfish and southern pygmy perch. It also supports populations of threatened Glenelg spiny crayfish, western swamp crayfish and turtles, as well as the critically endangered Wimmera bottlebrush. Managed releases from Lake Wartook for urban supplies and an environmental flow maintain a regular flow in the middle and upper reaches of the MacKenzie River and provide refuges for regionally important populations during dry periods.

Vegetation along Burnt and Bungalally creeks provides habitat corridors for terrestrial wildlife. Upper Burnt Creek contains an important native fish community and a threatened western swamp crayfish population, which is also becoming established in lower Burnt Creek. Mount William Creek supports regionally important populations of obscure galaxias, southern pygmy perch and rakali (water rats).

Dock Lake is a natural wetland that was modified and used as part of the Wimmera-Mallee System Headworks until 2010. When wet, Dock Lake provides feeding and breeding habitat for large numbers of waterbirds and frogs.

Ranch Billabong is a small wetland near Dimboola that supports river redgums, various aquatic plant species, waterbirds and frogs. It also includes a range of culturally significant plant species (such as sneezeweed).

In very high flow periods, the Wimmera River discharges Lake Hindmarsh and Lake Albacutya, large sub-terminal lakes. Lake Albacutya is a Ramsar-listed wetland, and Lake Hindmarsh is Victoria’s largest freshwater lake. Both provide significant habitat for waterbirds when wet.

Page last updated: 05/12/24