History of the Rio Grande reservoirs in New Mexico: Legislation and litigation

Nearly all of the dams and reservoirs on the Rio Grande and its tributaries in New Mexico were constructed by the federal government and were therefore authorized by acts of Congress. These congressional authorizations determine what and how much water can be stored, the purposes for which water can be stored, and when and how it must be released. Water may be stored for a variety of purposes such as flood control, conservation storage (storing the natural flow of the river for later use, usually municipal or agricultural), power production, sediment control, fish and wildlife benefits, or recreation. The effect of reservoir operations derived from acts of Congress is to control and manage the flow of rivers. When rivers cross state or other jurisdictional boundaries, the states are very mindful of the language in the congressional authorization. Simply put, an upstream state will want flexibility to store and use as much water as possible and, except for protection from extreme flood events, a downstream state will seek to guard against water being held that would otherwise flow downstream. When interstate compact obligations, ecological considerations, Indian and non-Indian water rights, and international treaties are thrown into the mix, a significant area of law develops concerning the reservoirs that is vital to each state and its inhabitants as well as to national interests. This article summarizes the federal acts and the negotiations among the affected states and other interests when the Rio Grande reservoirs in New Mexico were authorized, highlighting other important legal developments that have affected the operation of the dams.