0 Occurrences 1 Occurrences 2 Occurrences 6 Occurrences 
St. Louis Flood Protection Project System Location
City, County, and State of the levee system. Determined by the levee alignment location not the leveed area.
St. Louis, St. Louis city, Missouri
System ID
Unique identifier code for the levee system using 10 or 12 numbers in length.
5605410001
Operation and Maintenance Organization
Entity responsible for day-to-day management of the levee.
St. Louis City Street Dept. / Metropolitan St. Louis Sewer District
Floodplain Management
Entities responsible for regulating activities that occur in areas prone to flooding.
FEMA Region 7
Oversight Organization
Entity responsible for oversight of the levee and ensuring it is maintained.
USACE - St Louis District
Last Assesment Date Last Risk Assessment or Formal Inspection.
9/3/2020
Data Last Updated Date any of this information for the system has been updated.
4/24/2025
Levee Length
Combine length of all the levee system features including the embankments, floodwalls, closures where they exist for this system.
11.326 Miles Average Levee Height
The average height of the levee system. The levee profile viewer on the mapping window will show the actual levee height values for the length of the levee if available.
14 Feet Year Levee Constructed Year levee system was fully completed as a flood reduction project.
1974 Summary
General text description of the levee system with a summary of why the levee is there, and the benefits it provides.
The St. Louis Flood Protection Project Levee System reduces the risk of flooding from the Mississippi River and Maline Creek to portions of metropolitan St. Louis, MO. The system is federally authorized and constructed and operated and maintained by the nonfederal sponsor the City of St. Louis. The levee system was completed in 1974 and is approximately 11 miles in length, including 4 miles of earthen embankment and 7 miles of floodwall. Additionally, 27 pump stations are associated with the system, which are operated and maintained by Metropolitan St. Louis Sewer District (MSD). The system relies on a complex network of pump stations and pipes passing through or under the earthen embankment and floodwalls to discharge interior drainage from the leveed area. Over one hundred relief wells are installed throughout the system to reduce underseepage pressures in the foundation during high flood events. In 2014, USACE and the City completed a project to restore underseepage controls by replacing relief wells throughout the system. Toe drains, which are pipes along the land side base of the floodwall, are installed to reduce seepage pressures and prevent ponding water near the ground surface of the floodwall. During the record-setting Flood of 1993, significant floodwall movement occurred due to damaged toe drains and rapid emergency response by the City was required to prevent its failure. The 3,160-acre leveed area is a narrow piece of land along the Mississippi no greater than about one mile across at its widest point and is home to residential and commercial properties and many industries that depend on river commerce in St. Louis. Specifically, there are 13 chemical factories, numerous hazmat locations, electrical substations, and oil and gas facilities, as well as a correctional facility. This system provides benefits to nearly 7,500 residents and employees and more than $1.5 billion in property value. It has prevented the city from flooding during numerous flood events, including the flood of 2019 in which it is estimated to have prevented $194 million in damages.
Performance & Condition
General text description of the historical and anticipated performance of the levee, the people and property benefitting from the levee and who may be at risk of flooding, and actions to address areas of concern.
USACE completed a risk assessment in 2020. The assessment identified floodwall underseepage as the primary concern with the system’s ability to withstand a major flood event. Stability of the floodwall relies upon relief wells and toe drains. Damage and/or deterioration of these features have been observed due to both their age and vandalism, increasing the likelihood that seepage pressure from a flood event could destabilize the floodwall. There is also concern with aged pipes passing under the floodwall; sink holes near these pipes have been observed indicating potential damage. The extent of any damage sustained within the system’s foundation from previous floods is unknown. A system failure could result in flooding of depths from 6 – 15 feet, loss of life, and significant economic damage. The highly industrialized nature of the leveed area and the long-established residential areas contribute to high potential economic, social, and environmental consequences if flooding were to occur. Risk to public safety is higher during the day when people commute into the leveed area for work. However, the relatively narrow leveed area and good egress routes mitigate this risk to life safety.
Flooding Hazard
Historic Loading by Percentage of Height
Representative loading associated with historical flood information as a percentage of the levee height or overtopping.
Representative loading associated with historical flood information as a percentage of the levee height or overtopping.
0 Occurrences 1 Occurrences 2 Occurrences 6 Occurrences