Watch this until it converts you. This video shows the best case scenario. Water rushing over ag land, destroying relatively few buildings and killing relatively few people. It is dissipating energy the whole time as it approaches the highway that is acting as a levee. This is why we need set-back levees. This is how we should disperse floods. The only improvement I could see is to send floods over less capital-intensive agriculture, but even so, it isn’t a subdivision with houses full of children.
Also, that leading debris line is something to see.
Up until that wave hits the houses, this is what success would look like.