Water Supply
The Department of Water is responsible for the management of water and issues water allocation licences to the South West Region's three public water utilities, Water Corporation, Aqwest (Bunbury Water Board) and the Busselton Water Board.
Licences are also issued to private water users such as large horticultural enterprises requiring groundwater from confined aquifers. South of Bunbury, surface water resources were developed for public water supplies in a number of towns including Walpole, Pemberton, Manjimup, Bridgetown, Boyup Brook, Kirup, Balingup and Margaret River.
On the coastal plain, most towns are supplied with groundwater from the Yarragadee or Leederville Aquifers. These include Binningup, Bunbury, Eaton, Australind, Capel, Busselton and Dunsborough.
The Harris Dam, 12 kilometres north of Collie, supplies water to Collie and 31 towns connected to the Great Southern Towns Water Supply Scheme. This dam has recently been connected to the Perth Water Supply via the Stirling Dam. Irrigation is a major water user in the South West. The Water Corporation supplies bulk water to Harvey Water (formerly South West Irrigation Cooperative) from dams in the Darling Scarp, Waroona, Samson, Logue Brook, Stirling, Harvey and Wellington. The Glen Mervyn Dam near Donnybrook supplies the Preston Valley Irrigation Cooperative.
The Stirling-Harvey Scheme, based in the South West town of Harvey, is part of an integrated water supply system servicing the South West, Perth Metropolitan and Goldfields-Esperance regions. Officially opened in November 2002, it supplies up to 10 per cent of the Perth Metropolitan Region's water requirements.
A joint state and federal government project to decrease salinity and increase Western Australia's supply of drinking water was recently announced. The $30 million Collie River Salinity Recovery Project is designed to reduce salinity levels in the Wellington Dam with a long-term goal of making the water suitable for drinking by 2015.
Coastal plain groundwater is also used extensively for private irrigation, while the major groundwater resource of the Collie Basin is used for industrial purposes associated with coal mining and power generation.
The State Government recently announced that a second seawater desalination plant powered by renewable energy will be Western Australia’s next major water source. The proposed site for the facility will be on Taranto Road, north of Binningup, adjacent to a disused limestone quarry. It is expected to have minimal environmental and visual impact on the area, but will be subject to the usual approval processes.
The new plant will provide at least 45 gigalitres of water a year into the integrated water supply system by the end of 2011, with potential to increase to 100 gigalitres. The Water Corporation has advised that the estimated cost of building the second desalination plant will be $640 million. An additional $315 million will be required to connect the desalination plant into the water supply system (IWSS).
The Water Corporation provides rural drainage services in defined rural drainage districts. The Water Corporation also manages all public wastewater (sewerage) schemes in the South West and operates and maintains 26 wastewater treatment plants. Each wastewater scheme must be managed to meet health requirements, environmental conditions, as well as social and community needs.