Does the Endangered Species Act Preempt State Water Law?

In March 2013, in The Aransas Project v. Shaw, the U.S. District Court for the Southern District of Texas announced, almost in passing, that the federal Endangered Species Act (“ESA”) preempts state water law and the exercise of state water rights. As a result, the court concluded that the Texas Commission on Environmental Quality had effectuated a “taking” of ESA-listed whooping cranes as a result of state-permitted diversions of fresh water. This case is currently on review before the U.S. Court of Appeals for the Fifth Circuit, but it raises a question likely to be increasingly important for both aquatic species and water users: When, and to what extent, does the federal ESA preempt state water law, including the exercise of state-created water rights? This Article examines that question in much more detail than the Southern District of Texas did. It begins by examining the plethora of water systems in the United States that are already subject to ESA controversies as a result, at least in part, of water management decisions and water rights. For a variety of reasons, including both population dynamics and climate change, the number of such systems is increasing, and conflicts between the ESA and state water law are only likely to escalate in the future. In Part II, this Article reviews the basic jurisprudence of federal preemption, outlining the three ways in which federal law can preempt state law — express, implied, and conflict preemption. Finally, Part III examines how these three types of preemption play out through the ESA. The Article concludes that the ESA is unlikely to either expressly or implicitly preempt state water law in most circumstances, but that conflict preemption is likely to play an increasingly bigger role in ESA-water law jurisprudence, making The Aransas Project v. Shaw a harbinger of water rights litigation to come.