Consisting of a 10.9-mile-long system of floodwalls and levees, STLFPS is operated and maintained by the City of St. Louis and the Metropolitan St. Louis Sewer District (MSD). The purpose of this study was to provide supporting data to meet certification requirements for the flood protection system as outlined by the Federal Emergency Management Agency (FEMA).

Shannon & Wilson provided site reconnaissance to observe existing conditions; a review of existing documentation concerning the design, construction, and performance of the STLFPS; and a review of exploratory borings and laboratory testing.  Shannon & Wilson also identified and selected soil parameters based on the available subsurface information.  Geotechnical analyses included review of global stability and underseepage at selected embankment and floodwall locations, embankment erosion protection, and settlement relative to freeboard standards.