Apparently in some countries a windmill is associated with an image of poverty.
But in Australia a windmill is an image of life and prosperity. Much of inland Australia has no permanent surface water so during the annual dry season it would not be possible for animals, birds or people to live there if it were not for the supply of good quality underground water. Windmills are a very efficient, environmentally friendly way of pumping life-giving water to the surface.
The Federal Government Department of Agriculture, Fisheries and Forestry has an excellent summary of Australian rainfall (the annual average over the entire continent is a tiny 469mm), a map showing runoff rates for 12 main drainage basins in Australia, river flow rates (on average only 12% of Australia’s rainfall runs into rivers, compared to the world average of 65%), household and industrial water use and a map of groundwater basins, which includes the Great Artesian Basin.
The Great Artesian Basin is the world’s largest artesian water basin, covering 22% of Australia. It ranges from just 100m underground to more than 3km. Many bores in remote regions have had to have borecasing sunk to a depth of more than 1000m to reach the water.
Artesian water is water that rises up under pressure, hence the term ‘flowing bore’. Sub-artesian water rises but not right up to the surface so must be pumped at least some of the way up. Ordinary groundwater doesn’t rise at all so it must be pumped all the way up.
Often windmills are used to pump artesian water up into turkey nest dams, so the water troughs can be gravity-fed.
The two most well known windmill manufacturers in northern Australia are Southern Cross and Comet. Southern Cross produced their first windmills in 1876 and Comet in 1879. Other companies include South Australia’s Dean & McCabe Windmills and Western Australia’s W.D. Moore & Co.
The Queensland Department of Natural Resource Management has a useful article on the pros and cons of windmills, how to select the right size etc.
The largest windmills in Australia are found in the northern inland and for more than a century they have been taken for granted as part of the landscape that never changes. Unfortunately these huge windmills are now disappearing when they need repairing, often being replaced by submersible pumps. These are often preferred because they are cheaper to install and maintain, and skilled boremen are now becoming scarce.
Unfortunately the company who manufactures steel bore casing ceased regular production of certain sizes a couple of years ago. Now this bore casing is only made when users get together and place a very substantial bulk order. Some stations in mining areas are able to obtain secondhand casing from nearby mines. Used bore casing is used for a myriad of purposes, eg fence strainer posts.
Each state government department has a information sheet on putting down a bore, for example the Victorian Department of Sustainability and the Environment ( DSE ) the Queensland Department of Natural Resources and Water and the Northern Territory Department of Natural Resources.
Several beautiful windmills have been preserved at the Australian Stockman’s Hall of Fame in Longreach (Central Western Queensland), and there is a large windmill distinguishing the top end of Boulia’s main street. Hughenden has a seat These windmills are well worth a close look if you are out this way.
Tags: The Great Artesian Basin, Conservation and the environment