If it fails, it’s because in Communist countries, excellence is the enemy of just good enough.
My buddy who lived there when this thing was being built would say “good enough is the enemy of on-time completion”. They made it such a national priority that anyone who did anything that would have put work behind schedule would have gone into the concrete mix. In fact he claims the dam was made from poor quality materials to begin with, and somewhat jokingly mentions the two things they had plenty of: red clay and human dung.