We spent an awfully long time using this tilted container thing (a stream table) to explore how rivers are made.
We fill it with sand from outdoors, which means an exhausting hike to a giant pile of dirt. Then we pour water down it in numerous ways. Slow, fast, very tilted, slightly tilted, we do it all. Just when it looks like we are done, there is another thing to do- a lab! With our own controlled, manipulated variables. In other words, all we have to have in the lab is something about the stream table.
My group picks the best way to stop floodwaters. We use little Monopoly hotels. And the best one? The one that was uphill and had a wall of dirt at the bottom. The one where we made a wall of rocks and wood worked really well, also.
So folks, If you're in a hot spot for flooding, either raise your house or build a sandbagging wall. Or do what the authorities say and evacuate.