The five-metre mound has been built at the Whitesands, which is regularly inundated by the River Nith.
Officials behind the Â£15m river defence and regeneration programme hope it will demonstrate the scale of their plans.
Critics of the flood prevention scheme claim there are cheaper and less intrusive alternatives.
They have raised fears that it will result in a loss of car parking spaces but Dumfries and Galloway Council has pledged to create more on-street parking.
Colin Smith, who chairs the council's economy, environment and infrastructure committee, said the blueprint had been drawn up after careful consideration.
The model is part of a wider public exhibition at the former Baker's Oven in High Street, Dumfries.
A life-size model of an embankment planned to protect part of Dumfries from flooding has gone on display.