Some of the most striking damage was to Iowa’s roads. Floods closed off residential roads and highways across the state, including Iowa Highway 14 north of Marshalltown and sections of Highway 330. Emergency repairs have closed off Highway 1 near Mt. Vernon after floodwaters washed out a bridge on Monday.
Asphalt and concrete play a unique role in flooding as both victim and culprit of the damage. The surfaces of our roads and highways are made of two of the least absorbent materials around, resulting in immediate runoff and significant damage if drainage systems aren’t in place. This often results in heavy damage to roads and structures themselves, when the combination of soaked and washed-out soil beneath and high pressure from floodwaters above causes cracks, displacement and collapses.
Fortunately, most Iowa cities have vast drainage infrastructures to prevent roads from becoming waterlogged. Yet continued heavy rains, like Iowa’s record rainfall in June, will continue to put those systems to the test.