OK, I'll accept your post as you presented the clarification of it being based on opinion. A corked fishing bobber wouldn't be my choice of a control element in an experiment to display probable likelihood though given the scale of drag and weight of a square barge , nevertheless....point taken...! TS
Not just opinion, opinion based on the physics involved. In terms of the variables of mass and energy, a barge, no matter how massive (weight), when compared to the mass of the water in the river or lake (or the mass of earth in the levee, for that matter), is no more significant than that cork bobber floating in a bucket.
However great the mass of the barge, the amount of energy/force it can transmit to the levee by striking it is directly dependent on other factors, specifically the velocity (speed AND angle of incidence) with which it strikes. A barge travelling at a high rate of speed would transmit a greater shock to the levee than a slowly drifting barge. Likewise, a barge striking the levee perpendicularly would impact with more force than one hitting at an angle.
I acknowledged that we lack sufficient evidence to decide definitively, but the evidence we do have, including that from the Wall Street Journal article, applied according to the principles of physics, supports a much higher probability for the scenario I outlined.
I'm not just trying to be argumentative - I think it's important to point out that I was not saying the two scenarios were equally likely. The science greatly favors the erosion-failure scenario.