1. Upper Mississippi River levee and floodwall design standards (a) Updates required (1) In general In carrying out the Upper Mississippi River levee and floodwall projects, the Secretary of the Army, acting through the Chief of Engineers, shall not less frequently than every 20 years update the design probabilities used to establish the design profiles for levees and floodwalls, using the most recent probabilities and flood frequency profiles and current appropriate factors of safety as needed for wave action, settlement, other existing and anticipated future uncertainties, and Federal Emergency Management Agency guidelines to maintain accreditations. (2) Contents In updating the design probabilities under paragraph (1), the Secretary shall obtain public input at each stage of development, including base elevation data, base hydrological and hydraulic assumptions, and shall utilize a public involvement group for meaningful public engagement throughout the development of the updated flood frequency profiles. (b) Uniform flood protection Local sponsors of the Upper Mississippi River levee and floodwall projects in paragraph (b) may maintain flood protection at levels consistent with the profiles established under subsection (a) such that— (1) the maintenance for Uniform Flood Protection is hereby deemed as not injurious to the federally authorized flood protection project, and no change in risk transfer from original Corps of Engineers probability-based design, and previously approved alterations approved pursuant to section 208.10 of title 33, Code of Federal Regulations, prior to 33 USC 408 EC 1165–2–216 dated 31, July 2014; (2) alterations to the Upper Mississippi River levee and floodwall projects made prior to July 31, 2014, having met the standard established by section 208.10 of title 33, Code of Federal Regulations, are hereby federally authorized