Rivers are a shared resource. Like all rivers that originate in-state, Colorado must share the Rio Grande’s waters with its downstream neighbors. In the San Luis Valley, the 75-year-old Rio Grande Compact governs all things water . The river has been a source of tension, leading to litigation with New Mexico and West Texas, however, since 1966 Colorado has met all of its compact obligations. The compact dictates how much water Colorado must deliver at the New Mexico state line from both the Conejos River and Rio Grande mainstream and serves as a legal defense, giving the state certainty on the amount of water it can use.