Much better article with far more information -
http://www.seattlepi.com/news/article/Crack-in-Columbia-dam-affects-hydroelectric-system-5283908.php
Does not sound like anything to be too concerned about since it is a spillway. The system of dams in the Columbia Basin are very beneficial to those who live here as well as customers far away. I would love to see us expand hydroelectric energy production because it is so cheap, but the greens hate it.
Thanks for posting that. It was MUCH more informational. Sounds like it is nothing to get bothered about. It is not holding back water. It is just a really big speed bump in the spillway to slow down the water to reduce erosion downstream. Even if it fails, it is not going to collapse downstream dams.