Bradfield Nimmo

Most Members of the WRRA have been involved, in some way or another, in the analysis and reanalysis of Bradfield Schemes. The term "Bradfield Scheme" is colloquially used to refer to any scheme for diverting water from North Queensland's east flowing rivers, through the Great Dividing Range, to water the parched interior of the state.

The original Bradfield Schemes were proposed by the great Australian civil engineer, Dr John Job Crew Bradfield, in 1938. Bradfield is also famous for his involvement in the design and construction of the Sydney Harbour Bridge and Brisbane's Story Bridge. In his early career, he gained experience in water engineering by working on Cataract and Burrinjuck Dams. He was awarded the degree of DSc in engineering by the University of Sydney. This was the first doctorate in engineering awarded by that university.

Bradfield's proposals for the rivers of North Queensland were published by the Courier Mail on 1st October, 1938 in an article by him titled Augmenting Queensland's Inland Water Resources.

Early in the following decade, Bradfield produced an expanded version of his proposals. This version suggested that diverting water to inland Australia would alter the climate there and generate additional rainfall. The new version was titled Watering Inland Australia.

By the second half of the 1940s, considerably more relevant data had been amassed than had originally been available to Bradfield. A team of engineers reviewed the original proposals in the light of the better information. The findings were presented in a report published in the Queensland Bureau of Industry Annual Report for 1947-48. The findings were signed by W Nimmo and titled The Bradfield Scheme.

Dr William Hogarth Robertson Nimmo provides an interesting parallel with Dr Bradfield. Dr Nimmo became the first recipient of a full Doctorate in Engineering from the University of Queensland. Dr Nimmo had received the first DSc in engineering from the University of Sydney. Dr Nimmo also had a very distinguished career. He was the Chief Engineer of the Stanley River Works Board which constructed Somerset Dam. He went on to be Commissioner of Water Resources.

The photographs at the top of this page show Dr Bradfield (left) and Dr Nimmo (right).

The Nimmo analysis showed that

  • some components of Bradfield's proposals were impossible or impractical
  • there were practical possibilities to fill the gaps
  • the supply of water would not be as great as Bradfield had envisaged because
    • natural streamflows were less than Bradfield's estimates
    • the level of the offtake from Hells Gate Dam limited the storage available for regulating the available supply
  • the huge cost militated against implementation of the proposals.

Since the original Nimmo response, there have been many reanalyses of variations on the original Bradfield theme. Interest is particularly intense at election time. Somehow, election commitments always seem to include funding for more investigations but not for construction.

During the 2020 Queensland state election campaign, one of the political parties trotted out a variant of Bradfield's proposals called the New Bradfield Scheme. In this variant, water from the Hells Gate Dam was to find its way into the Warrego River and continue south towards (but not cross) the border with New South Wales.

One of the problems that Bradfield sought to address has been largely mitigated by other means. In the introduction to his article in the Courier Mail, he points out that flows from artesian bores were steadily decreasing. If the decrease continued unchecked, most bores would no longer have sufficient pressure to bring water to the surface and would require pumping. In 1989, the Queensland Water Resources Commission introduced a formal program of bore reconditioning. Bores were recased, if necessary, and fitted with headworks to limit the flow to what was needed. On many properties, the old bore drains were replaced with pipes for reticulating the water and this produced further savings of water that otherwise ran to waste.

Now our very own Bob McDonald has done his very own reanalysis of the practicality of diverting water to the west from Bradfield's proposed dam at Hells Gate on the Burdekin River. He presents his findings in a very readable report titled Exploring the Bradfield Scheme.

25th July, 2021