Garrison Dam, North Dakota. The 70-mile Missouri River reach from Garrison Dam to the outskirts of Bismarck is wide and unchannelized. In a manner similar to the unchannelized reach from Yankton, South Dakota, to Ponca, Nebraska, the Missouri’s high flows remain largely within its banks along this section. Because it is able to enter its former floodplain, the Missouri’s channel area absorbs the bulk of the floodwater exiting the spillway and tunnels at Garrison Dam. But on the northern edge of the state capital, riprap and housing developments encroach on the river’s meander belt. The river’s narrowed channel area cannot carry the floodwaters safely past Bismarck. When the water flows down from the dam above, it hits the confined channel and rises. Once again, simple observation makes it apparent that suburban housing construction in the floodplain exacerbates flooding.