I’ve only been to Colorado twice in my life, so I may be ignorant on this: but didn’t they build a series of dams and floodgates back in the 1940’s to prevent this sort of thing?
All the dams in this area are full or overflowing.
The land is mixed. In steep mountain canyons, a wall of water can be dozens of feet high. Note the earlier pictures.
In the flat plains, a stream can go from a few feet before the rain to 20 feet high and miles wide now. Many of the older homes/farm buildings from the 1800s are on small hills = dry ( smart old boys then ). Many of the newer trailer parks and such may be under water even though they could not see the river before now.