Kurtr isn't wrong. Sakakawea, Fort Peck, and Oahe are the big 3 along the Missouri River, usually they try to equally distribute the total amount of water (relatively speaking) between those three reservoirs. They came into fall way out of whack, and they've been rebalancing the system to bring them back into a more equal amount of full going into spring.
And just so you know, there's always someone along the Missouri in the Bismarck area complaining about the "low water" on the river. I hear it all the time from friends and acquaintances.