Growing populations and economies will increase competition for water resources around the world. Furthermore, desiccation of surface water supplies via climate change will not only exacerbate disputes over current water supplies but also increase pressure on groundwater resources, already stressed in some parts of the world. Since water resources respect no political boundaries - sometimes not even intra-national or intra-state boundaries - equitable agreements to govern, manage, and protect these resources are essential to the social and economic well-being of all water users. While formal agreements for equitably governing and managing transboundary surface water resources are common and well-understood, the development of similar transboundary groundwater agreements is in its infancy.