Ground water rights, spatial variation, and transboundary conflicts.

The goal for any property rights system is to achieve equity, efficiency, and certainty. Trying to achieve these goals for ground water is difficult because a ground water right is not exclusive. To make matters more complicated, ground water is often under the jurisdiction of more than one political unit. The result is transboundary conflicts. Two critical elements must be included in any system of ground water rights. The system must define how the ground water can be used and define the relationships that each user and each use has with the other users and uses in the system. Unfortunately, these relationships are seldom completely defined and are made more complex by the transboundary scales at which they operate. As ground water moves horizontally across boundaries, different users or different jurisdictions have sequential control, creating conflicts between the first users and subsequent ones. Other problems occur because of vertical relationships, with more than one person or entity having control over ground water at the same time. This simultaneous exercise of authority can create conflicts between an individual who possesses a right to use ground water and a state or federal agency that regulates the same water. Transboundary conflicts occur at different scales and include conflicts between neighboring property owners as well as conflicts between countries. Scale, the property rights structure, and the nature of the relationship between users influence the way transboundary ground water conflicts are resolved.