As Texas’s population continues growing, the state is struggling to forestall a looming water crisis. Tarrant Regional Water District, a Texas state agency, sought to purchase some of Oklahoma’s water from the Red River, which forms a boundary between the states. Tarrant’s efforts failed because Oklahoma’s water permit laws disfavor out-of-state purchasers. Tarrant sued the Oklahoma Water Resources Board and claimed in part that Oklahoma’s laws create an unconstitutional restriction on interstate commerce. In Tarrant Regional Water District v. Herrmann, the Supreme Court affirmed the Court of Appeals for the Tenth Circuit and dismissed Tarrant’s Commerce Clause claim as meritless. This Comment argues that the Supreme Court’s holding could hinder interstate cooperation in solving water shortages.