Supplement A of the Main Report focuses its attention on the process of formulating a comprehensive plan for the water and related land resources of the Susquehanna River Basin. It covers primarily the activities of the Plan Formulation Workshop, whose responsibility included the analysis of alternative means of meeting the water and related land resource needs of the Basin through the year 2020. The contents of this volume were selected to provide background on the rationale for including key features in the comprehensive plan. To solve most water resource problems, present and future, a number of choices are available--choices that must be made in light of the broad public interests and the planning objectives selected for this study.