A ﬂoodway is a man-made channel built as a branch or a neighboring bed to a river that tends to ﬂood. It provides a secondary course for the river’s swelling waters during high-water stages. (The U.S. Army Corps of Engineers also uses the term to refer to that part of a ﬂoodplain with rapid downstream ﬂow.) Floodways are more common to Canada than the United States, and one striking example (as viewed in vertiginous aerial photos) is a bypass of the Red River around Winnipeg. The narrow Red, which deﬁnes North Dakota’s eastern border on its route to Hudson Bay, is so tempestuous it can ﬂood to a width of sixty miles, as it did in 1997. Floodways have also been constructed on the Colorado, below Davis Dam; on the Missouri, their mechanics here located within a series of Army Corps of Engineers dams; and on other rivers whose regular ﬂooding has caused devastation to property.