About water

Water Sources | The Otway Supply System | The Dilwyn Aquifer | Grampians Supply System | Balmoral Supply System | Newer Volcanic Aquifer | Glenthompson Supply System | Clifton Formation

Wannon Water supplies drinking water to customers over 24,000 square kilometres, which is divided into 34 drinking water localities and various non-drinking water regions. 

Wannon Water supplies approximately 12,500 megalitres of water to customers each year. This water comes from an array of sources including protected forested catchments, agricultural land, plantation forests and groundwater aquifers.

Surface water under is extracted under a bulk water entitlement orders from Gellibrand River (North and South), Arkins Creeks and Victorian Range tributaries in the Grampians National Park. The usage out of Konongwootong Reservoir, the Glenthompson Reservoir the Dunkeld emergency storages and Wannon Water's usage out of Rocklands Reservoir are also under bulk entitlement orders.

Additional surface water is collected in Wannon Water owned reservoirs and via supply from Grampians Wimmera Mallee Water's Rocklands Reservoir and Willaura Pipeline. The remainder of the water is supplied from groundwater bores, 21 bores are located throughout the region.

Water Sources

Below is a summary of the water sources for localities serviced by Wannon Water.

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The Otway Supply System

Arkins Catchment
This is a closed catchment comprised of more than 750 hectares of native forest which forms part of the Great Otway National Park.

Gellibrand River North and South Off Takes
The Gellibrand River catchment is comprised of agricultural land, native forest and plantation forest along with numerous small urban developments. Water is extracted from two locations on the Gellibrand River. The North Otway system harvests water from the Gellibrand River near the Carlisle River township and the South Otway system which pumps water from the Gellibrand River at Chapple Vale.

The Warrnambool Albert Park Bores
The Albert Park bores are used to extract groundwater to supplement supply from surface water flows for Warrnambool, Koroit and Allansford, providing 10 per cent of their water requirements.

Carlisle Borefield
Two bores situated near the Carlisle River township are used to supplement the supply from the Gellibrand River during times of low flow in the river.

Storages

There are several storages in the Otway system. The largest of these is Tank Hill Reservoir with a capacity of 750 megalitres which along with Donald's Hill Reservoir, Mount Ewen Reservoir and Warrnambool Storage provide a buffer between summer demand and system input capacity. These storage basins are relatively small and only hold about 10 weeks of peak demand.

For more information on the Warrnambool Koroit & Allansford water supply system, visit our Fact Sheets page.

The Dilwyn Aquifer

The Dilwyn Aquifer is a large underground water source which stretches across much of south-west Victoria and south-eastern South Australia. Wannon Water extracts from the Dilwyn aquifer at:

• Portland
• Port Fairy
• Heywood
• Dartmoor
• Port Campbell

For more information on the Dilwyn Aquifer, please visit our Fact Sheets page.

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Grampians Supply System

Water is harvested from various steams and groundwater bores located in the Grampians National Park.

Download the Water Catchment Protection - Grampians National Park brochure. 

The water is piped and stored in three major basins located to the north of Hamilton. The three reservoirs are Hayes Reservoir, Cruckoor Reservoir and Hartwichs Reservoir.

The water supplied to Hamilton and district is treated at the Hamilton Water Treatment Plant (WTP) to conform with the Australian Drinking Water Guidelines. Following treatment at Hamilton, water is piped to Tarrington (9 kilometres) and Dunkeld (30 kilometres). Upstream of the Hamilton WTP the water is diverted to the Cavendish system where it is disinfected prior to delivery to customers.

For more information on the Grampians Supply System, please visit our Fact Sheets page.

Balmoral Supply System

The Glenelg River catchment is comprised of national park, state parks, private agricultural land and feeds the Rocklands Reservoir.  This reservoir is managed by Grampian Wimmera Mallee Water and has a 348,000-megalitre capacity.  Wannon Water pipes water from Rocklands Reservoir to the Balmoral Service Basin prior to treatment and distribution to the township of Balmoral.

Newer Volcanic Aquifer

The newer volcanic aquifer extends across the basalt plains of south-west Victoria.  Wannon Water extracts water from this aquifer at:

• Penshurst
• Caramut
• Mortlake (to supplement the surface supply from Terang)

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Glenthompson Supply System

Water is harvested from two farmland catchment areas located to the south of the Glenthompson township. Water is stored in the Glenthompson Reservoir and the Railway Reservoir. The water supply is supplemented through a pipeline from the township of Wallaura which is supplied by Grampians Wimmera Mallee Water.

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Clifton Formation

The Clifton Formation forms a high yielding aquifer and occurs at economic depths of less than 200 metres. The Macarthur bore intersects the confined Clifton Formation aquifer on the edge of the Macarthur township.

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