Sponsored by the Task Committee for the Shared Use of Transboundary Water Resources of the Environmental and Water Resources Institute and the Laws and Institutions Committee of ASCE. This report proposes clear standards and principles for effective and efficient water sharing among two or more autonomous political bodies. Drawing from existing transboundary agreements, this report presents a series of model codes that could limit the potential for conflict while providing an appropriate balance among efficient use of the water resource for economic purposes, public health, and ecological protection. Three model agreements are presented for use according to the willingness of the parties to forgo sovereignty. All three models?coordination and cooperation, limited purpose, and comprehensive management?focus on the allocation and use of shared waters and on resolving conflicts involving such waters. These three water sharing agreements can be used within the United States and, with minor alterations, in the international arena.