Cranky Rock has been, to my memory, the chosen site for a Belubula dam for over 60 years. It was as logical in the 1950’s as it is today and tomorrow. The structure of the chasm at the opening that the river runs through is underlying solid rock which would only require superficial cosmetic preparation for the concrete or earth/rock wall and the water could provide a degree of hydro-power electricity for the grid.
Don’t attempt flood mitigation if you value the silt that is deposited on the river flats down-stream.
They were created by silt falling out of suspension as flood water slowed down when it spread over low areas.
Why not get on with it and stop prevaricating.