This isn’t getting a lot of press attention, but for the first time in its 57-year life, Garrison Dam’s spillway is being opened during flood season in North Dakota. There will be unprecedented flooding downstream. Other dams on the Missouri (such as Oahe) are also releasing water because they are full of rain and snow runoff. Tens of thousands of people won’t be flooded, mainly because there isn’t that much housing in low-lying areas and because of heroic efforts shoring up flood dikes.
I grew up in this area. As a child, I was told that the reason we didn’t have floods was because of those huge dams (Garrison is the fifth largest earthen dam in the world). That’s not true anymore.