As a studying geologist, I find such a simplistic reduction to be very absurd, there are many factors which influence how that released energy causes its damage. Are there physical impediments in the way? Are there breaks in the path of flow? Is the environment already used to this amount of water flowing through it suddenly (the evidence of life everywhere says no so no surprise a ton of life gets lost when it suddenly blows through.)

Such a simplistic reduction also does serious disservice to the structural geologists, soil analyst techs, and others in the geological profession whose work focuses on preventing exactly this sort of situation. It's more complex than "Volume and speed."