The water was expected to provide irrigation for more than of agricultural land in Queensland. The scheme would reduce the massive natural erosion problems in areas of Central Queensland. The scheme had the ability to generate of power and the potential to double that amount. It is claimed that extra water and vegetation in the interior may then produce changes to the climate of Australia, however various studies have concluded that this is unlikely. This may increase the rainfall in areas of southern Queensland and northern New South Wales. Extra rainfall may drought-proof Eastern Queensland, and thereby improve river inflows to the Murray-Darling River system. It is claimed that a full Lake Eyre would moderate the air temperature in the region by the absorption of sunlight by the water instead of heat radiation from dry land into the air. No evidence to support the theory that an inland sea would increase rainfall has ever been produced, nor have any of the other claims been supported. On the contrary, the book "The Great Boomerang" by Ion Idriess, it is reported that on two occasions when Lake Eyre filled up with floodwater, the eastern seaboard reported good harvests for the preceding 7 years. It would provide large areas suitable for the production of algae fuel, a type of biofuel. The catchment area of the Herbert River holds a population of approximately 18,000, 75% of whom dwell in the lower flood plain area. Diverting some water from this river would reduce the risk of flood.
Objections
Bradfield's scheme and others have been criticised because they are not practical. This scheme has been criticised because of the high capital and ongoing running costs which would make the project uneconomical. Elevation measurements were taken with a barometer, leading to inaccuracies in land heights and mistakes in the proposal. In most cases no flow record of the rivers were available to Bradfield. He used an empirical formula which assumed 33% of the water flow would be lost to evaporation and seepage. The estimated water available for the scheme was. The extreme evaporation rate in the interior is another negative determinant. No clear evidence has been provided that the amount of water supplied will exceed the evaporation rate. The reduction in river discharge to the Great Barrier Reef Lagoon may diminish coastal fisheries by reducing the supply of terrestrial organic matter to the coastal and estuarine environment. In 1947, W.H.R. Nimmo, conducted a critical review of the scheme. He proved that Bradfield's estimates of the amount of water available from the easterly flowing rivers were about two and half times greater than it actually was. The error was attributed to the methodology used to calculate flow estimates was based on German rivers where the average temperature was much less than in northern Australia.
Support
The Bradfield Scheme has not received broad political support from any of the major Australian parties in recent times, but it has been pushed by individual politicians such as Bob Katter, who advocated the plan whilst he was a member of the Nationals for the state seat of Flinders during the 1980s, and continues to support it as an independent, representing the federal seat of Kennedy. In February 2007, the then Queensland PremierPeter Beattie urged the Federal Government to look at a modern version, saying it is better to find more water than to cut back on current supplies. However, Beattie preferred desalination. Former Nationals leader Barnaby Joyce and Pauline Hanson's One Nation party also support the scheme.
