While publications exist on conflict resolution for water resources, most focus almost exclusively on surface water with occasional mention of groundwater. No books focus exclusively on conflicts over groundwater resources despite the fact that most of the world's freshwater supplies are underground, that over 300 transboundary aquifers have been mapped, and that over 50% of the world's population relies on groundwater for drinking water. In Contesting Hidden Waters, the author describes the principal differences between surface water and groundwater disputes. First, groundwater conflicts are more focused on water quality and land use as opposed to water quantity and allocation which typify surface water disputes. Secondly, groundwater is the "hidden" resource where unlike surface watersheds which are static, groundwater boundaries are value-laden, constantly changing during development and also include the spectrum of spirituality and mysticism, economics, and property rights. Thirdly, conflicts over groundwater include identity issues typically not encountered in surface water conflicts. Finally, conflicts over aquifer storage are shown to be different to conflicts over groundwater. This is highlighted by the United Nations General Assembly recently adopting a resolution on the "Law of Transboundary Aquifers" bringing groundwater and aquifers to the fore. The book covers both the theory and practice of conflict resolution, including detailed case studies from the Middle East and USA.