This report is a cooperative project of the Illinois State Water Survey and StateGeological Survey. Part 1, prepared by the Geological Survey, discusses the geologic history and character of bottom sediments. Parts 2 and 3 were prepared by the Water Survey. Part 2 presents the hydraulic and hydrologic conditions of the Chain. Part 3 discusses the water quality and sources of nutrients and the living organisms. Part 3 also evaluates remedial measures found effective in other locations and proposes a reliable water managementprogram.
This publication represents a condensed version of an extensive report on the distributions of heavy rainstorms in Illinois, based on data for 61 precipitation stations operated during 1901-1983. Shown are annual frequency distributions of point rainfall for periods ranging from 5 minutes to 10 days and for recurrence intervals varying from 2 months to 100 years. Results are presented in two forms: mean relations for ten regions of approximately homogeneous precipitation climate, and statewide isohyetal maps based on the 61-station data The report also discusses the results of a special investigation pertaining to Chicago and the surrounding six counties subject to urban influences on the precipitation distribution. The final section of the report provides information on the urban influences on the two Illinois counties adjacent to St. Louis.
The Benchmark Sediment Monitoring Program for Illinois Streams was initiated by the Illinois State Water Survey in 1981 to generate a long-term database of suspended sediment transport. The program is now part of the Water Survey's Water and Atmospheric Resources Monitoring (WARM) Network, which monitors the climate, soil moisture, surface water, ground water, and sediment throughout Illinois. This report summarizes the suspended sediment data collected for the program during Water Years 1994 and 1995. All the techniques used in the data collection process and laboratory analyses are based on U.S. Geological Survey procedures and techniques. The report appendices present tables of instantaneous suspended sediment measurements, particle size analysis, sediment transport curves, and plots of instantaneous sediment concentrations for the period of record for the current monitoring stations.
The Benchmark Sediment Monitoring Program for Illinois Streams was initiated by the Illinois State Water Survey in 1981 to generate a long-term database of suspended sediment concentrations and instantaneous sediment loads. The program is now part of the Water Survey's Water and Atmospheric Resources Monitoring (WARM) Network, which monitors climate, soil moisture, surface water, groundwater, and sediment throughout Illinois. This report summarizes the suspended sediment data collected for the program during Water Years 1998 and 1999. All the techniques used in the data collection process and laboratory analyses are based on U.S. Geological Survey procedures and techniques. The report appendices present tables of instantaneous suspended sediment measurements, particle size analysis, sediment transport curves, and plots of instantaneous sediment concentrations for the period of record for the current monitoring stations.
A dense raingage network has operated in Cook County since the fall of 1989, to provide accurate precipitation for use in simulating runoff for purposes of Lake Michigan diversion accounting. This report describes the network design, the operations and maintenance procedures, the data reduction methodology, and an analysis of precipitation occurring during Water Year 1999 (October 1998 through September 1999). The data analyses include 1) monthly and Water Year 1999 amounts at all sites, 2) Water Year 1999 amounts in comparison to patterns from network Water Years 1990-1998, and 3) the ten-year network precipitation average for Water Years 1990-1999. Also included are: raingage site description, instructions for raingage technicians, documentation of raingage maintenance, and documentation of high storm totals.
Systematic measurements of ground-water levels in Illinois were started in the early 1930s in the Chicago region. Measurements were made in 1961 in 220 observation wells in 42 counties throughout the state. In areas remote from pumping centers, no long-term continuing trends of general rise or decline of the water table are discernible. A large part of central and southern Illinois experienced a severe drought beginning early in 1952 and ending in most areas during the spring of 1955. As a result, ground-water levels declined to record-low stages especially in the southern one-half of Illinois. However, large quantities of ground water taken from storage within the ground-water reservoir were replenished during succeeding years as precipitation increased. In heavily pumped areas, changes in water levels caused by pumping are superimposed on seasonal and secular fluctuations due to natural phenomena.In some instances large developments of ground water have caused pronounced and serious declines of water levels. There are many areas of ground-water development where serious water-level declines have not occurred.
A primary concern in the management of the Lower Cache River is the amount of sediment that is deposited in the river's valley in the vicinity of Buttonland Swamp. From previous monitoring studies it is known that floodwaters from Big Creek convey a significant amount of sediment and create a reverse flow condition in the Cache River that carries the sediment into Buttonland Swamp. This study investigated the potential influence of several management alternatives in reducing or eliminating the reverse flow condition in the Cache River, which would alleviate much of the sediment concern. Management alternatives include various options for detention storage in the Big Creek watershed as well as redirecting the lower portion of Big Creek to the west, away from Buttonland Swamp. To evaluate the impact of these alternatives, the hydrology of the Big Creek watershed and its influence on the hydraulics of the Lower Cache River were investigated using two models. The HEC-1 flood hydrology model was used to simulate the rainfall-runoff response of tributaries draining to the Lower Cache River, with emphasis on Big Creek and estimating the impact of detention storage on the Big Creek flood flows. The UNET unsteady flow routing model was then used to evaluate the flow patterns in the Lower Cache River and the impact of management alternatives on flow direction, flood discharge, and stage. Under existing conditions, the UNET model shows that reverse flow occurs in the Lower Cache River east of Big Creek confluence during all the flood events considered. Various detention alternatives in the Big Creek watershed have the potential to reduce the peak of the reverse flow by 26 to 76 percent. Of the detention alternatives examined, the larger detention facilities in the lower reaches of Big Creek appear to produce the greatest reduction in reverse flows. An alternative to divert the lower portion of Big Creek has the potential to totally eliminate reverse flows in the area immediately east of the Big Creek confluence with the Lower Cache River, but may cause increased flooding to the west. To eliminate most of the reverse flow east of Big Creek, and at the same time not increase flood stages farther west on the Lower Cache River, it may be necessary to use a combination of detention storage and either a partial or total diversion of the lower portion of Big Creek. For example, the use of the split flow alternative in combination with the many ponds and Cache valley detention alternatives reduces the peak reverse flows east of Big Creek by 81 percent for a 2-year flood and 92 percent for a 100-year flood. This combined alternative also accomplishes a reduction in the peak stages farther downstream west of Interstate 57 by approximately 0.5 foot.
The Illinois River has become a focus of state and federal agencies and other organizations interested in integrated watershed management. As a result, issues related to habitat restoration, floodplain management, navigation, erosion and sedimentation, and water quality of the Illinois River are being discussed at the watershed scale. In support of this effort, the Illinois Scientific Surveys have initiated development of the Illinois Rivers Decision Support System (ILRDSS) for use in documenting project activities within the watershed and assessing and evaluating the effectiveness of potential restoration projects and management practices. The ILRDSS will integrate and expand existing databases and numerical models of segments of the Illinois River into an integrated decision support system (DSS) for the entire Illinois River watershed. New databases and models also will be created for the watershed, as well as a comprehensive ILRDSS web portal to all available data and information about the Illinois River and its basin. This report describes the current status of ILRDSS development and serves as an introduction to those unfamiliar with the Illinois Rivers Decision Support System.
Brochure describing the research and services available from the Midwestern Regional Climate Center (MRCC) help to better explain climate and its impacts on the Midwest, provide practical solutions to specific climate problems, and allow us to develop issues-based climate information for the Midwest. Our data and information focus primarily on applications to climate-sensitive sectors and scientific research. In addition to providing on-line access to the interactive, subscription-based Midwestern Climate Information System (MICIS), the MRCC web site provides climate statistics for the Midwest and links to climate resources around the country.
Fall application of nitrogen (N) fertilizer is a common practice in Illinois to help overcome the uncertainties of spring field work and to reduce the potential for delay in planting of spring crops. If, however, the N is applied while soil temperatures are above 50F, significant N losses can occur before the crop can take up the N. The lost N can pollute the state's water supplies, resulting in harm to the environment. The objective of this work was to provide agricultural community and public access to near real-time, 4-inch bare soil temperatures measured at 10:00 a.m. Central Standard Time (CST) each day. Hourly soil temperatures are measured at 18 automated weather stations in Illinois operated by the Illinois State Water Survey (ISWS). These stations make up the Illinois Climate Network (ICN). Measured weather variables include 4-inch sodded soil temperature, solar radiation, air temperature, relative humidity, barometric pressure, precipitation, and wind speed and direction. These data are collected, quality controlled, and placed on a Web site (http://www.sws.uiuc.edu/warm/soiltemp.asp) for public access. Daily maps of the 4-inch bare soil temperature are derived from a combination of actual 4-inch bare soil measurements at 8 ICN stations and computed bare soil temperature from 4-inch sodded soil temperature measurements from the remaining 10 sites. These maps allow users to see the general pattern of the 10:00 a.m. CST soil temperature from which they can estimate soil temperature at a given location. The other measured weather variables also are presented on the Web site in map format. Steven E. Hollinger and Robert W. Scott, Water and Atmosphere Resources Monitoring Program, Atmospheric Environment Section and Office of the Chief, Illinois State Water Survey, 2204 Griffith Drive, Champaign, Illinois 61820-7945