Few events define contemporary historical imagination of the bottoms more than the great flood of 1993. With seasonal high water on the Mississippi paired with localized rainfall in the region, the flood overtopped the levees of the Columbia Drainage and Levee District on August 1—one of more than 1,000 federal and non-federal levees that was breached during the flood—despite days of aggressive sandbagging by locals, volunteers, and US Army Corps of Engineers personnel. The ensuing flood set off a chain of responses by the corps that included the intentional breach of levees downstream to alleviate pressure on the levees protecting the historic town of Prairie du Rocher. Additionally, in a move that is almost unthinkable in the American context of property identification, following the near-catastrophic flooding of the town of Valmeyer, the community, with Federal Emergency Management Agency (FEMA) support, voted on the wholesale relocation of the town from the bottomlands to the bluffs above the floodplain.
The hydrology of the 1993 flood is worth pause, as the breach location is counterintuitive: it did not occur on a levee paralleling the river; rather, it occurred in the middle of the floodplain on one of the parallel levees that tracks back across the bottomlands to the bluff. This levee complex forms a series of enclosed, dry bathtubs—with levees defining three sides and the bluffs the fourth. What this means is that once the levee system is breached, it serves as a basin in which floodwaters are stored with no way to escape back out to the river. Such was the case in 1993, as the waters that filled the basin rose to a level above the grade of the adjacent river. This hydraulic inversion is what prompted the intentional breach of the levees on the southern end of the district.
Standing at this point, one can discern a slight rise in the levee road—an index of the reconstruction of the levee after the floodwaters receded. Here, the pressures of the floodwaters cascaded through the lowland vector defined by Moredock Lake and aimed right at the community of Valmeyer.