The situation which presents its self – needs not be explained. The answer to these things is water; and when it does not rain then something drastic must happen. Maybe a modified Bradfield Scheme is the answer. Bradfield built the Sydney Harbour Bridge..so he would recognise the worth of a couple of Sydney Harbours (1,000 gigalitres) sent down the Darling each year.
The situation with the Bradfield Scheme, basically is moving water from the Flinders River south. Recently there has been a big flood and a little of that sent to the Darling would save the day – Fish in the Darling and the complaining from South Australia.
Hughenden on the Flinders is 324 m above sea level and Charleville 294 M above sea level. So by having a drain from Hughenden to the Charleville probably picking up the Warrego River system east of Tambo- means that a pipeline or drain would be about 4 to 500 Kms long
Prime Minister Scott Morrison has promised $180 million for the Hughenden Irrigation Scheme on the Flinders River, Queensland’s longest. A further $54 million will be spent on building Big Rocks Weir on the Burdekin River near Charters Towers in the first step of the massive Hells Gates Dam proposal..This proposal will get volumes of water to Hughenden
The pipeline to Charleville , or the Warrego River could be made of reusable products , plastic bottles, if found suitable..Australia has a problem disposing of this waste. So we could kill two birds with the one stone.
If there was required some pumping along the way even though there is a general fall and my experience of the lay of the land is that it fairly level. To lift the water where necessary solar power could be the answer.
A small system would cover the requirements listed above and fix up the fish . The system could be enlarged to accommodate lots of irrigation. There is a lot of water there for everyone