Intended for a general audience, Water Law provides both a general overview of basic water law doctrines and an exploration of how water law—the law and policies governing allocation of water—fit into broader ecological and environmental law issues. The book provides an overview of important hydrological principles before discussing the major state-law systems governing use of water in the United States—riparian law, prior appropriation, and specific groundwater doctrines. It then explores the federal government's interests in the fresh waters of the United States, ranging from protection of navigability to water infrastructure projects to reserved federal water rights. Putting the law governing water use into a broader context, Water Law then explores the intersections of state water law with energy policy and production, water quality protections, endangered species protections, and broader watershed management. It ends by returning to the concept of water rights as protected private property rights and the complexities of constitutional "takings" litigation when environmental protections interfere with those rights.