St. Johns Levee and Drainage District attempt to mitigate internal flooding

Excerpt

When the Mississippi River reaches 87.9 m (290 ft) above sea level near New Madrid, Missouri, bottomlands adjacent to the river and farmland, roads, ditches and wetlands begin to flood. Concurrently, at the lower end of the New Madrid Floodway the rising Mississippi backs up into Main Ditch (figure 1), the 454 m (1,500 ft) gap in the frontline levee designed to drain the Floodway and St. Johns Levee and Drainage District to the river (figure 2). When this occurs, the Main Ditch gates on the setback levee (figure 3) are closed to protect the St. Johns Bayou basin from Mississippi River backflow. However, with the Main Ditch gates closed, precipitation within the basin has no outlet as it drains to the Main Ditch channel. This causes tributary streams to back up and flood a substantive portion of agricultural lands and the town of East Prairie, Missouri. For example, the 19 cm (7.5 in) of rain during the first three days of May of 2011 backed up local floodwater in the St. Johns Bayou basin all the way to East Prairie.

The construction of the Commerce to Birds Point to New Madrid levees (figure 2) artificially separated lands within St.…