In the United States water law is a subset of property law that controls the use and allocation of the water resource. Water law was, and remains, state law; nothing in the Constitution purports to change that. The scope of federal sovereignty at the time of nationhood did not include even the possibility of playing a major role in regulating resources because the national government was not a significant landholder. The twentieth century changed water federalism dramatically. In the twentieth century, even while laws and rhetoric respected the division of authority favoring the states, the real power over water in most basins passed into the federal government's programmatic and regulatory control, creating a mismatch of supposed authority and actual power over water. Now, at the outset of the twenty-first century, federal control of federal projects and programs greatly reduces the sphere of influence of state water law and the ability of the states to allocate water to the uses that best serve their respective public interests. The federal imperatives that may have justified that shift when the relevant laws were enacted are now half a century old and seem out of touch with the modem reality of water management. A new statute that employs a structure similar to that of the Coastal Zone Management Act of 1972 will put the states back in control of the water and concurrently use federal authority in a role for which it is well suited.
Robert H. Abrams, Correcting Mismatched Authorities: Erecting a New "Water Federalism," 25 Nat. Resources & Env't 22 (2010)