Colorado weather can swing from one extreme to another in just a few short days. It's not all that unusual for the monsoonal flow to cause a flood down a canyon but I don't think it's ever happened down that many canyons at once and all of it is flowing into the same river so they're getting a lot of flooding downstream too.
And then Aurora got drowned again today and it's supposed to rain quite a bit up and down the front range again tomorrow. The very last they need.