The Des Moines River-Red Rock Reservoir Remedial Works Avon Station is a flood risk reduction system located in Polk County, Iowa, being bordered by the Des Moines River to the north, and adjacent to Avon and Avondale Lakes. These lakes are separated by a band of raised earth that supports a railroad line formerly used by the Chicago, Rock Island, and Pacific Railways. This levee system is a part of, and maintained by, the Red Rock Reservoir. The Avon Station Remedial Works were designed to protect the residential development around Avondale Country Club Lake (roughly 320 acres) from a Red Rock Reservoir elevation of 785 (NGVD29) with 3 feet of freeboard. Due to the influence of Red Rock’s pool on this location the remedial works were not designed to a specific flow. The design elevation was obtained by routing the standard project flood through a half-filled reservoir (antecedent pool elevation of 763.6) according to the Avon Station Remedial Works Design Memorandum No. 30 (1964). The standard project flood and probable maximum flood (PMF) for Red Rock Reservoir have not been updated based on current guidance. Protection of Avon Station against high reservoir levels is achieved by construction of 2.1 miles of embankment on three sides of the low lying area. The levee ties into gigh ground. The levee has a crown width of 10 feet (which includes 3 feet of freeboard) with 1-on-3 side slopes at elevation 788.0. The height of the levee averages just over 6 feet, with the maximum height about 12 feet. According to the 1965 General Design Memorandum (GDM) No 30 the project consists of protecting 320 acres of land with a levee around three sides of Avon Station. The Remedial works include an earthen levee, road ramps, and a sandbag railroad closure provided by the United States Army Corps of Engineers to protect the community. The earthen levee begins at high ground southwest of Avon Station and runs easterly until it crosses Southeast 60th Street, Southeast Avon Drive, and the Railroad track. It then extends north some 3,000 feet before turning west to the high ground just west of Southeast 56th Street. It is designed to contain a Standard Project Flood routed through a half-filled Red Rock Reservoir. The levee crosses the railroad track at the southeastern corner of the project. A sandbag closure is required in the freeboard zone. Preparations for placing sandbags at this closure will be initiated whenever it is anticipated that the stage of Red Rock Reservoir will exceed full flood pool elevation 780.0. Roads were ramped up to the levee crest.