Galena was almost lost due to catastrophic flooding with each spring thaw. The town was built on the banks of the once mighty Galena River, and poor land management lead to the silting in of the river and valley. The combination of those and other factors meant the downtown area would be flooded almost annually, with particularly bad floods occurring in 1911 and again in 1937.

Congressman Leo Allen, a resident of Galena, successfully lobbied for and oversaw the building of the levee system you see today, complete with doors that open and close to keep downtown safe from the devastating floodwaters.

In the 21st century, a wall was added to extend flood protection to Riverside Drive, the section of South Main Street stretching from the flood gates to the Frank Einsweiler Bridge.