The Commerce clause, interstate compacts, and marketing water across state boundaries.

Increasing competition for scarce water resources should lead to a re-examination of constraints on water reallocation. Some constraints are spatial in nature and reduce the areal extent of reallocation processes. Interstate compacts are an example. Proponents of state protectionism look on compacts as a permanent allocation of water between states. A willing seller is not allowed to sell their water to a willing buyer in another state. On the other hand, the U.S. Constitution\u27s Commerce Clause was designed to create an economic union that includes all states and all citizens. State attempts at economic protectionism through export bans are generally unconstitutional unless they can pass one of the limited exceptions to the Commerce Clause. One potential exception is through the use of interstate compacts. The question examined here is to what extent can interstate water compacts act as a constraint on water marketing? Allocations contained within an interstate compact should be looked on as an initial allocation of water, not a permanent one. In this article we examine the Rio Grande Compact in detail and interstate compacts in general to determine whether compacts place limits on water markets between states