divebuddy,
My points about sandbags and the fate of invading water were based on direct observational experience of sufferers in two towns over many decades.
The points "lettered" (a) - (c) were general comment and not aimed at our princes in particular. The "number" 2 learning points were in (a) only. But I reckon they know it anyway. Badly phrased by me tho' divebuddy.
As regards the obvious weight of wet sandbags, I doubt if the princes will be removing them so no "learning" point there.
However you disagree about the value of sandbags - remember that we are discussing a mass flood disaster, not prevention of a single tidal or rain event which results in inches of water.
Short of building a solid impermeable wall, water does reach its own level. Given a gap or permeability and the physics holds as the princes would agree.
During this terrible situation, I will not be getting involved in further dispute.
SIQ.