Welcome to the 7-Day 10-Year Low Flow Maps web site. This site provides electronic copies of the paper maps that are contained in Illinois State Water Survey contract reports ISWS CR 440, ISWS CR 441, and ISWS CR 545 , or as updated since 2002. These maps provide information on low flow conditions that might be expected to occur only during droughts (once in 10 years), and associated effluent discharges, water withdrawals, and flow regulations for most Illinois rivers and streams.       View Maps Background Contact Information Instructions to view a map or download a map are available. These maps were developed by the Illinois State Water Survey with cooperative funding from the Illinois Environmental Protection Agency. | Low Flow Home | View Maps | Map Info | Background | Contact Info | Help | | Home | Highlights | Staff | Data | Information | Centers | Site Map |   Illinois State Water Survey, Contact Information University of Illinois at Urbana-Champaign All files and information © 2009 Illinois State Water Survey. Terms of use. Email the Web Administrator with questions or comments. Last Modified: June 24, 2005