St Louis is nicknamed The River City. The reason for that is very simple. It sits approximately at the confluence of the Missouri and Mississippi rivers, the two biggest rivers in North America. But besides those, other, much lesser known rivers also flow through the area. One thing rivers do is flood. So that means yes, St Louis is known for flooding.
Let me caveat all of this by saying that some parts of St Louis flood more than others. The original City of St Louis was built on the high ground in the area, so what we can call old St Louis is surprisingly flood resistant. But two floods of historic proportions occurred in 1844 and 1993.
A floodwall along the Mississippi River protects downtown St Louis from flooding. Built to withstand the volume of the 1844 flood, it protected downtown in 1993, but with less than 3 feet (and less than 1 meter) to spare.
Threats of flooding from other rivers
The part of the City of St Louis that is most prone to flooding is near the confluence of the Mississippi River and the River Des Peres. If you’ve never heard of that one, you’re probably not from St Louis. During normal times, the River Des Peres is really not much of a river. It’s more like a drainage ditch, and nearby Gravois Creek may have more water in it than this so-called river. But when the Missouri and Mississippi are at or near flood stage, the River Des Peres gets quite a bit mightier. And under the worst conditions, the Mississippi isn’t draining any of it off. I’ve heard speculation that the opposite happens, that water from the Mississippi wants to bleed into the River Des Peres.
And when that happens, the South St Louis neighborhood known as Carondelet as well as the suburb of Lemay are both prone to flood.
One of the reasons St Louis is so much larger than East St Louis is because of the topology. When the Mississippi River floods, it tends to flood the Illinois side. The Mississippi River doesn’t flood nearly as much on the Missouri side of the St. Louis metro area.
The flood threat largely comes from other rivers in the area.
Missouri River flooding
The Missouri River can flood some of the St Louis suburbs, particularly the suburbs in St Charles county and the suburb of Chesterfield. The area of Chesterfield known as Chesterfield Valley can sometimes flood catastrophically. I’ve seen it in my lifetime. The major commercial district in Chesterfield, where there’s approximately a mile of big box stores was almost all underwater during the flood of 1993. When someone decided to plant a Lamborghini dealership in that area, I didn’t think it was the best idea ever. In 1993, that area was farmland. The Ford dealership was there, and I remember it being underwater. We’re talking 8 to 10 ft of water.
Meramec River flooding
Further south, the Meramec River is very much prone to flooding. The athletic fields near the river all along the edge of south St Louis and northern Jefferson counties very much have a tendency to flood in the spring. They don’t necessarily flood every year, but the tendency of those areas to flood is the reason why that land is athletic fields.
For that matter, the land along the rivers that is high enough to not flood tends to be very valuable. The modern suburb of Oakville borders the Mississippi River. The river bluff is high enough not only to not flood, but also to give a spectacular review. There was a time when the social elite of St Louis would live in one of the gated communities near the Chase Park Plaza hotel during the week and have a weekend/summer home in Oakville.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.