Excerpt
In the spring of 2013, the highest floodwater levels in the last 70 years were recorded on the Illinois Waterway (NOAA 2013), a 541 km (336 mi) navigation system of rivers, lakes, and canals running from Lake Michigan (Chicago, Illinois) to the mouth of the Illinois River at Grafton, Illinois, on the Mississippi River (figure 1). River traffic, made possible by eight lock and dam structures on the waterway, was halted when the dam at Marseilles, 247 river miles above the Mississippi River, was damaged. On April 19, 2013, the currents and winds on the Marseilles pool above the dam caused seven barges to break free and crash into the Marseilles Dam. Four of the barges sank (figure 2). These barges blocked the southernmost spillway submersible tainter gates used to maintain the 2.7 m (9 ft) navigation channel and prevented gate adjustments to release excess water from the pool. Floodwaters backed up for many kilometers and flooded adjacent Illinois River bottomlands, including the town of Marseilles (figure 3). Approximately 1,500 residents were evacuated from the low-lying areas, and more than a meter (3 ft) of floodwater surrounded 200 homes and building structures and destroyed at least 24 homes. Many other…
- © 2014 by the Soil and Water Conservation Society