a website of the Illinois State Library

This is a list of all documents accepted for permanent retention under the subject classification 'Natural resources and the environment: Weather: Floods'.

Natural resources and the environment:
   Weather:
     Floods

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1993 flood on the Mississippi River in Illinois, The (1994) [MP-151]
This report on the 1993 flood on the Mississippi River in Illinois and on the lower reaches of the Illinois River was prepared by the Illinois State Water Survey with assistance from the Illinois Department of Transportation/Division of Water Resources and the Illinois Natural History Survey. The report begins with a brief description of the physical setting of the Upper Mississippi River System, including historical facts on climate, precipitation, hydrology, and floods. The 1993 flood is discussed with regard to precipitation, soil moisture, stages, flows, levee breaches, and discharge through levee breaches. Also discussed are impacts of the flood on social, economic, hydraulic and hydrologic, and environmental aspects of the river and its residents. Impacts on water quality, the environment, and public water supplies, including the beneficial and detrimental aspects of the flood, also are included. The lessons learned from this flood focus on the performance of the levees, governmental responses, the effects of flood fighting, change in stages due to levee breaches, flood modeling, and the lack of information dissemination to the public on the technical aspects of the flood. These lessons point out information gaps and the need for research in the areas of hydraulics and hydrology, meteorology, sediment transport and sedimentation, surface and groundwater interactions, water quality, and levees. The report presents a comprehensive summary of the 1993 flood as far as climate, hydrology, and hydraulics are concerned.

After the Flood
This information is provided by the Illinois Department of Public Health to help flood victims protect themselves against diseases and other hazards in the days and weeks following a flood.

Effect of Stratton Dam operation on flood control along the Fox River and Fox Chain of Lakes (1992) [CR-533]
The purpose of this study was to use models to simulate the effect of the Stratton Dam operation, and possible structural modifications such as the addition of Foster gates, on flood stages and discharges in the Fox River and the Fox Chain of Lakes. The hydraulics and hydrology of Stratton Dam, the Fox River, and the Chain of Lakes were simulated for a wide range of historical flooding conditions and potential operation schemes. Responses for many different major flood conditions were analyzed, but two particular aspects of flood control were given special attention: 1) increasing outflow from the lakes in anticipation of a major flood, and 2) facilitating the flow release of the lakes by adding Foster gates at Stratton Dam and downstream at Algonquin Dam. This information will provide the IDOT-DWR with information for implementing possible modifications to the Stratton Dam operation during flood conditions.

Effects of riparian tree management on flood conveyance study of Manning's Roughness in vegetated floodplains with an application on the Embarras River in Illinois (2002) [CR-2002-02]
Riparian forests have been proposed by the Technical Advisory Subcommittee of the Upper Embarras River Basin Commission in its alternatives for mitigating flood damages in the Village of Villa Grove and nearby farmlands. In order to evaluate potential reduction in flood stages in Villa Grove, methods for accounting for flow resistances induced by the riparian forests are needed in the hydraulic model for the Upper Embarras River. This project has been designed to better apply the available knowledge in practical field applications, particularly, how to evaluate the vegetal roughness in terms of Manning's <EM>n</EM> coefficient for specified planting scenarios. Approaches presented in this report are literature review on Manning's roughness with emphasis on vegetative roughness, and evaluation and selection of methods for computing vegetative roughness due to riparian forests. The Petryk and Bosmajian (1975) method was selected for evaluating Manning's <EM>n</EM> for mature trees because parameters could be reasonably obtained with available general field information. Using this approach, effects of riparian forest on floods were evaluated with the scenarios that the two-year floodplain has two densities of trees. The study reach was the channel between Villa Grove and Camargo. Also investigated were the options of having uniform tree density for the whole reach or half of the reach. An interface has been developed for implementing the computed <EM>n</EM> values to a HEC-RAS hydraulic model, and capacity curves were developed to illustrate the effects on flood conveyance among these scenarios. The capacity curves thoroughly included possible boundary conditions and were presented in simple nomographs that relate discharge and downstream elevations to a specified flood elevation in Villa Grove. Therefore it was easier to evaluate the resulting effects of different alternatives.

Embarras River watershed digital floodplain mapping, Champaign County, Illinois (2002) [CR-2002-05]
The project objective was to assimilate the best available data to prepare digital maps of critical riparian corridors and areas at risk of flooding for the upper Embarras River, East Branch Embarras River, and Black Slough in Champaign County. Hydrologic, hydraulic, and digital data defining streams and floodplains were reconciled with digital orthophotos of the Embarras watershed. Using orthophotos as base maps, digital data sets were prepared of streams and rivers and floodplain boundaries expected for a flood having a one percent chance of occurrence in any given year. These maps were developed to provide easy-to-interpret information that identifies areas at risk during flood events. The maps were developed using ESRI ArcGIS 8.1 software and are on the attached CD-ROM in ready-to-print PDF format. The CD-ROM format is compatible with Microsoft Windows Operating System Version 95 or later. The CD-ROM contains the HEC-RAS hydraulic model used to simulate flood elevations, digital coverages used to compose the maps, digital photos of bridge crossings and landscapes of the watershed, and this report. Graphs of channel thalweg and water surface profiles showing the depth of flooding for the biennial flood event (2-year flood) and the one-percent annual chance of occurrence flood (100-year flood) provide additional information.

Executive Order (2006, 5)
Governor's Executive Order concerning construction activities in special flood hazard areas

Flood protection and management for the Lower Illinois River system, Phase III : real-time simulation of floods with managed LDD storage options (2003) [CR-2003-03]
This report documents the structure and the use of an improved version of the Windows-based interface of the unsteady flow model, UNET. This interface was developed by the Illinois State Water Survey for the Office of Water Resources, Illinois Department of Natural Resources. The current version of the interface program can download historic, real-time, and forecasted stage and flow data from U.S. Geological Survey, U.S. Army Corps of Engineers, and National Weather Service Web sites interactively. These data can be used to update an existing Data Storage System (DSS) database or to create new ones. The interface allows the user to create or update gaging station information in a Microsoft Access database. The user can create project files to run the UNET model for historic, design, real-time, and forecasted flood events. The graphing function allows plotting of single and multiple hydrographs, or stage profiles of a single reach and multiple reaches. The utility tools include screen captures, document editing, and DSS file editing. This interface program uses the original UNET generic geometry and boundary condition files to maintain the same level of accuracy as the UNET model, but it also allows the user to change some of the parameters, such as, the simulation time interval, time windows, and numerical Corant number, and etc., in the BC file. Real-time simulation of a flood event simulates flood stage profiles using real-time stage and flow data downloaded from related Web sites. Locations and magnitudes of levee overtopping will be displayed for the lower Illinois River should these occur. The interface program lets the user modify parameters to simulate simple levee failure or two types of complicated embankment failures, overtopping and piping. Simulations also can be performed using the modified levee information, such as breaches or revised crest elevations. The change of water surface elevation induced by modifying levees can be compared with another simulation graphically and also in table format. Stage profiles from all simulations can be plotted together with levee heights on both sides of the channel along the Lower Illinois River to visually show the impacts of particular floods.

Illinois Natural History Survey Reports (1999, 355 January/February)
Quarterly publication. Contents of this issue include: Franklin's Ground Squirrel: An Increasingly Rare Prairie Mammal; Forest Regeneration and Understory Dynamics Following the 1993 Flood on the Illinois River; Development and Application of a Gambusia Bioenergetic Model; Monitoring the Spread of Western Corn Rootworm Beetles Infesting Illinois Soybean Fields; Species Spotlight: Short-tailed Shrew; The Naturalist's Apprentice: Shrew Mathematics

Illinois River: working for our state, The (1991) [MP-128]
The Illinois River is at a crossroads. All the events in its history, both natural and those accomplished through human intervention, are now poised to change the river in ways that may render it unrecognizable in our own lifetimes. This publication is intended to introduce you to the Illinois River and the issues that will shortly determine its very survival.

Management strategies for flood protection in the Lower Illinois River, Phase I: Development of the Lower Illinois River-Pool 26 UNET model (2001) [CR-2001-10]
One of the main concerns was the ability to specify proper stage hydrographs at the downstream boundary of the Lower Illinois River for hydraulic design and analysis. We found that a unique stage-discharge rating relationship does not exist at the lower boundary of the Lower Illinois River at Grafton because of backwater effects from the Upper Mississippi River. Management options and results for managed storage and emergency activities need to be analyzed under more comprehensive design of flooding conditions. To improve the capability of UNET for modeling backwater effects for the Lower Illinois River, an extended model including Pool 26 of the Upper Mississippi River was developed. The downstream stations of the model are at the tail of Lock and Dam 25 and the Mel Price Lock and Dam pool, where stage readings are available. The model was calibrated with a 1979 flood and verified with a 1983 flood. Discharge and stage frequency analysis have also been performed for stations at Troy on Cuivre River, Lock and Dam 25 tail, Lock and Dam 26 pool, and Mel Price Lock and Dam on the Mississippi River.

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