"The study area includes the main-stem Upper Mississippi, Lower Missouri, and Illinois Rivers. The Upper Mississippi is that portion of the river above the mouth of the Ohio River and includes the Illinois River. The Lower Missouri is that portion of the river below Gavins Point Dam. The Study was carried out using best available data and advanced modeling technologies. Nationally and internationally recognized scientists in the fields of hydrology and hydraulics provided direct guidance to the study via two technical advisory committees. Additional technical and floodplain management expertise was brought to bear through a standing Federal and State Interagency task force. Study results have undergone two independent technical reviews. Multiple levels of review support the accuracy of the results. The Corps and partnering State and Federal agencies have analyzed the effects of reductions in flood runoff attributable to flood control reservoirs, considered potential effects of levee overtopping and/or breaches, and have selected the appropriate hydraulic model to develop water surface profiles for a range of flow frequencies."
U.S. Army Corps of Engineers, Rock Island, Illinois: http://www.mvr.usace.army.mil/