As of this morning, it appears that the Cedar River of eastern Iowa has crested at 22 feet in Cedar Rapids and should begin falling within 24 hours, sparing the city the widespread destruction that occurred in 2008. If the levees hold through tomorrow, residents of Cedar Rapids can relax a bit, at least for this round of storms.
Following heaving precipitation across the Upper Midwest in August, the region received copious rain over the past week as storms trained from eastern Nebraska to central Wisconsin; the highest rainfall totals, reaching almost a foot, occurred along the Minnesota-Iowa border. The Cedar River rises in southern Minnesota and flows 338 miles to the SSE through eastern Iowa, entering the Iowa River before the latter enters the Mississippi; Waterloo and Cedar Rapids are the major cities along its course.
Except for flash flooding, which often occurs on small tributaries, major river flooding most often occurs in cities far downstream from the headwaters (below most of the watershed) and usually develops days after the storms have passed. Of course, regional topography may augment the risk for flooding, either hemming in the river flow or slowing its runoff. Prized for their beauty, water supply, transport and recreation opportunities, river valleys are often challenging places to live.