Regional water supply

Goldfields and Agricultural Region

The Goldfields and Agricultural Water Supply (GAWS) provides the majority of the water to towns in the Goldfields and Agricultural Region via the 566km long Goldfields pipeline that runs from Mundaring to Kalgoorlie, with extensions north and south. Water is sourced from Mundaring Weir near Perth, and supplemented with other IWSS sources when required.

Localities in the Goldfields Region that are not along the Goldfields pipeline receive their supply from local ground or surface water sources.

When the Goldfields pipeline was opened in 1903, it was the longest fresh water pipeline in the world and the first major pipeline in the world constructed of steel.

Integrated Water Supply System

The GAWS is part of the integrated scheme supplying the metropolitan area and some towns in the South West. This scheme is known as the Integrated Water Supply System (IWSS) and draws on surface sources, groundwater and seawater desalination to supply fresh, clean drinking water to more than 1.5 million people.

	History of the Goldfields and Agricultural Water Supply

South West Region

Towns in the South West Region obtain water from small water supply schemes or surface and groundwater sources that are largely independent and not connected to a major scheme.

Harvey, Waroona, Hamel, Binningup, Myalup and Yarloop are exceptions, being supplied from the Integrated Water Supply System.

Margaret River Water Supply

The Margaret River Water Supply Scheme provides drinking water to Margaret River, Cowaramup, Prevelly Beach and Gnarabup. Ten Mile Brook Dam is the Scheme's primary water source, and water from the Margaret Rives has been used to supplement supply when required. To meet long term requirements, we are investigating groundwater options that, in conjunction with Ten Mile Brook Dam, will secure sustainable water supply for the area.

Bridgetown Regional Water Supply

Bridgetown, Boyup Brook, Hester, Greenbushes, Balingup, Mullalyup and Kirup rely on small local dams for drinking water. In recent years work has begun on the Bridgetown Regional Water Supply Scheme. When complete, the scheme will link the seven towns to a single network of supply sources and infrastructure. The groundwater component of the Scheme, a bore near nannup, was completed in 2009 and has been used to boost supply to Bridgetown, Boyup Brook and Hester, via Millstream Dam when needed

Fore more information on current works and plans for the future in the South West Region:

	Water supply projects in the South West

Great Southern Region

The major water supply schemes in the Great Southern Region include the Great Southern Towns Water Supply Scheme (GSTWS) and the Lower GSTWS.

Harris Dam is the major source for the GSTWS, however approximately half the localities have local sources (primarily surface water), which can contribute to supply if required.

The GSTWS supplies high quality drinking water to Collie and 32 towns in the Upper Great Southern - over 40 000 people. The Harris Dam is the major source for the GSTWS, with local sources that supplement when required. Harris Dam is located 12 kms north of Collie and is the second largest dam in the South West, after the Wellington Dam, and holds 72 million kilolitres. Localities that are not serviced by the GSTWS have local sources such as small catchments or dams, and bores.

The Lower GSTWS, which supplies Albany and Mount Barker, has two sources including a series of borefields to the south west, and a surface water source to the north east of Albany. The remaining localities in the region have local supplies and are not connected to a major scheme.

	Water supply projects in the Great Southern

	History of the Great Southern Towns Water Supply Scheme

Mid West Region

The towns in the Mid West Region use groundwater sources that are largely independent and not connected to a major scheme. Major town's water sources and supply's are summarised below.

Kalbarri

Kalbarri has two water supply schemes, one which supplies Port Kalbarri and the other the remainder of the town. Both Kalbarri water supply schemes are from a ground water source.

The main Kalbarri scheme is supplied from 4 production bores located 2km south-east of the town site. Bore 2/86 is the main production bore for the scheme. The Port Kalbarri scheme is supplied by one production bore. A second bore has recently been redrilled and is expected to be equipped in 2011.

Water from the Kalbarri borefield is transferred to the treatment plant for disinfection (chlorine added) and aeration for pH correction. Water is stored in the 2,500 kL Kalbarri Service Tank before being gravity fed into the reticulation. Water from the Port Kalbarri bore is transferred to the treatment plant and disinfected using chlorine. Treated water is transferred to the elevated 370kL tank before being gravity fed into the reticulation.

Geraldton

Geraldton water is from a groundwater source. The aquifer that supplies Geraldton forms part of the Yarragadee Formation, a vast store of groundwater that stretches from Allanooka in the north to Augusta in the south.

Since 1967 Geraldton has been supplied from the Allanooka and Mt Hill borefields situated 55 km south east of Geraldton. There are 19 production bores of various capacities supplying Geraldton, 13 of these being in the Allanooka Borefield with the remainder at Mt Hill. The bores are between 50 and 150 metres deep. The Allanooka bores are the main supply of Geraldton’s water with the Mt Hill bores only being used to help meet summer peak demands.

Exmouth

Exmouth’s borefield includes 19 low yielding production bores and 1 ‘emergency’ bore which can deliver water quickly in the event of a cyclone warning.

The borefield draws upon a fresh groundwater lens at the foothills of the Cape Range which overlies the marine environment. The sensitive nature of the groundwater system requires careful management to minimise disturbance from multiple users.

The groundwater is chlorinated and delivered to a storage tank (via a series of above ground pipes). The storage tanks holds 5 Megalitres (enough to fill 2 Olympic swimming pools) and cycles approximately every 1.5 days in response to demand. The treated water is gravity fed into a series of reticulation schemes that supply residential, commercial and industrial users.

	Water supply projects in the Mid West

North West Region

The West Pilbara Water Supply Scheme supplies customers in Karratha, Dampier and the neighbouring towns of Roebourne, Wickham and Point Samson. Broome, Port Headland and other towns and areas are supplied by independent surface and groundwater sources.

Port and South Hedland

Port Hedland and South Hedland are supplied with drinking water via the East Pilbara Water Supply Scheme. The system has two independent groundwater sources, the Yule River and De Grey River borefields. The licensed allocation from the sources is 13.5 gigalitres per year.

While the current demand on the scheme is less than the licensed allocation, commitments to industry and domestic growth will fully utilise the capacity of the scheme when they are taken up.

West Pilbara Water Supply Scheme

The West Pilbara Water Supply Scheme draws freshwater from two sources – the Harding Dam, located South East of Roebourne on the Harding River, and the Millstream bore field, located inland from Karratha.

The Millstream bore field draws freshwater from an underground aquifer covering approximately 600 square kilometres. Water in the aquifer is contained in a limestone basin, about 20 to 25 metres underground. The Water Corporation has eight production bores available at Millstream to pump freshwater up out of the aquifer and into a pipeline that transports the water over 150km to the scheme’s coastal towns.

Burrup desalination plant

To help relieve demand on the water supply scheme, a small desalination plant is in operation under a special agreement to supply water for industrial purposes.

The Burrup desalination plant was constructed in 2005 and is capable of producing 3.6 million litres of desalinated water everyday. The seawater supply scheme consists of a seawater pumping station including filtration and chlorination facility, seawater pipeline, two million litre storage tank, desalination plant and saltwater return pipeline.

Broome

Broome’s town water supply comes from the Broome Sandstone underground aquifer, located north east of town. There are 18 bores in total, capable of drawing up to 22 million litres of water per day from the Sandstone Aquifer.