Flood-Inundation Maps for Dardenne Creek in St. Charles County, Missouri, 2019: U.S. Geological Survey Scientific Investigations Report 2020-5060 [open pdf - 4MB]
From the Purpose and Scope: "This report describes the development of a series of estimated flood-inundation maps for Dardenne Creek, St. Charles County, Mo., and identifies where on the internet the maps can be found and ancillary data (geographic information system [GIS] flood polygons and depth grids) can be downloaded. The study extent includes a 9.9-mile (mi) reach from 0.12 mi upstream from the USGS [U.S. Geological Survey] streamgage in O'Fallon, Mo., to about 0.82 mi downstream from the USGS streamgage in St. Peters, Mo. The maps were produced for flood levels using hydrologic data from four USGS streamgages (05514840, 05514860, 05587450, and 05587498;[...]) including two gages in the Dardenne Creek study reach (05514840 and 05514860) and two streamgages on the Mississippi River (05587450 and 05597498). Flood levels were referenced to the stage recorded at streamgage 05514860, Dardenne Creek at Old Town St. Peters, Mo., near the downstream extent of the study reach; and maps indicating the potential extent of Mississippi River backwater in the study reach were referenced to streamgage 05587450, Mississippi River at Grafton, Illinois."
Scientific Investigations Report 2020-5060
USGS Publications Warehouse: https://pubs.usgs.gov/