[Paul R.]

Downstream levees are also a big worry.

http://www.sacbee.com/news/state/california/water-and-drought/article133326709.html

[Paul R.]

One more article:

http://www.mercurynews.com/2017/02/17/oroville-dam-cause-of-emergency-wont-be-known-for-a-long-time-state-says/

That main spillway is a big structure itself: 178 ft. wide and 3000 ft. long. That helps give (at least me) a better perspective of the violence of the water when it hits that damaged area.