We need to construct huge Irrigation Water Canals across the country to turn the red centre into a Nile Delta. All open Canals covered with Solar Panels to minimise evaporation during the day. Where they slide back during the night to allow the rise of moisture from them to spread over crops and the land - just like the ancient South Americans used to do to attain their vast crops.
The bigger Canals could also accommodate small shipping. No problem in the Wet Seasons up north which would provide much needed fresh water to transfer all around the dryer parts of the country. Even from QLD and Northern NSW where it rains hard and floods. Instead of the water sitting there like a dirty city duck pond, it drains away to drought stricken areas. It may knock a metre off the flood level in an immediate way.

This is the only way to improve Farming and Living in the interior of Australia.
This is the INLAND SEA.