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.