This footage claims to be "unseen" because it's taken from behind the barrier lines. Honestly with so many videos and pictures coming out from the flood, you may have in fact seen this.

As we see more and more pictures and video coming out of the disaster zone, it isn't getting any easier to grasp what happened. It's just hard to believe this happened in our community. However we will bounce back from this. We will work together and we will recover!

The video's description says this:

Big Thompson from Great Dam behind Ellis Ranch to the Glade road areas north of Sandy's gas station, directly west of road 23H along top of highway 34 George Rist canal, Consolidated Home Supply Ditch & Reservoir Company diversion point, many shots not seen on news, access behind police lines.