The program of basic water-resources investigations by the U.S Geological Survey in the Midwestern states is a highly coordinated undertaking. It represents a partnership among Federal, State, and participial agencies that has developed during the past 60 years from the mutual desire to obtain and maintain optimum knowledge of out water resources with a minimum outlay of public funds. The program is sufficiently broad to include investigations of water from all natural sources including the chemical and physical quality of water from each of these sources.