This animation illustrates how a standard Polychem chain and flight scraper system is assembled and installed.
The Australian state, territory and federal governments have reached a landmark agreement on water to save rural communities and safeguard the nation's farms.
The Council of Australian Governments (CoAG) agreed on a framework for a national water trading system that will enable farmers to buy water from other parts of the country.
The federal government increased to $200 million its share of a $500 million fund to help buy back water for the environment.
"There has been an historic decision for $500 million worth of action to repair the River Murray which is the nation's lifeblood in terms of our environmental and economic future," SA Premier Mike Rann said.
NSW and Victoria will contribute $115 million, South Australia $65 million and the ACT $5 million.
But farmers and environmentalists, while happy with the agreement, said more had to be done before rural communities and the rivers were safe.
Banks have started withholding investment in irrigation farms because of questions over the security of their access to water.
Under the CoAG plan, water will gain the same legal status as land, guaranteeing compensation to farmers who surrender water for the environmental goals.
A stocktake of water ownership will be conducted as a precursor to the national water market.
Urban Australians will also have to bear some of the pain of change, using more recycled water and cutting their overall water usage.
Prime Minister John Howard hailed the agreement.
"It's a great outcome for farmers, it's a great outcome for environmentalists, it's a great outcome for the nation," he told reporters.
Premiers and chief ministers were also supportive of the plan, describing it as a major achievement for Australians.
While there was general agreement, many of the details have been pushed back until the CoAG meeting in autumn next year.
National Farmers' Federation president Peter Corish said it was vital the details, such as the rules governing the water market, were worked out quickly.