The economic prosperity and the well-being of our nation's communities depend on the reliable functioning of critical infrastructures: transportation, banking and finance, information and communications, water supply systems, emergency services, and especially energy (electric power, oil, and natural gas). In the new economy, these infrastructures are increasingly reliant on information technologies and are strongly affected by restructuring and other market forces. They are much more heavily interconnected than ever before, and disruptions in one system can have significant adverse consequences, both locally and regionally. Communities often are not well prepared to deal with widespread infrastructure failures, which could become commonplace in the new millennium. This report, prepared on behalf of the partnership, is a first-of-a-kind effort to compile this type of information on the electric power system in a form that municipal governments can use and adapt to local conditions. ComEd and Harza Engineering Company have provided valuable support for this effort. Argonne National Laboratory's Infrastructure Assurance Center compiled and integrated the planning information.