"The availability and sustainability of an adequate and dependable water supply is essential for public, environmental, and economic health. This understanding led to the initiation, under the direction of Executive Order 2006-01, of a three-year program for comprehensive regional water supply planning and management in Illinois. The Illinois Department of Natural Resources' Office of Water Resources (IDNR-OWR), in coordination with the Illinois State Water Survey (ISWS), selected two regions having a high potential for water conflict--east-central Illinois and northeastern Illinois--for pilot planning under the framework of the Order. This report summarizes technical studies in support of water supply planning in the northeastern Illinois region, which includes Boone, Cook, DeKalb, DuPage, Grundy, Kane, Kankakee, Kendall, Lake, McHenry, and Will Counties. These studies highlight the opportunities and challenges of meeting water demand in the region. ... The Chicago Metropolitan Agency for Planning (CMAP) guided formation of a 35-member grassroots water supply planning group for northeastern Illinois, the Northeastern Illinois Regional Water Supply Planning Group (RWSPG). The RWSPG was charged with developing water supply planning and management recommendations for the region. The Illinois State Water Survey (ISWS) and the Illinois State Geological Survey (ISGS), both within the University of Illinois' Prairie Research Institute, along with the Illinois Department of Natural Resources' Office of Water Resources (IDNROWR), were responsible for providing technical support to the RWSPG ... The rwSPG was assigned the responsibility of developing water demand scenarios to 2050, which was accomplished via contract with investigators at Southern Illinois University-Carbondale. The purpose of this report is to describe the water resources from increased withdrawals to meet prescribed scenarios of water demand to the year 2050." -- from Introduction, page 1.