A Horse Named “Stream Depletion Theory”: The History and Negotiation of the Upper Colorado River Basin Compact

The 1922 Compact only apportions the beneficial consumptive use of the river system’s waters between two geographic sub-basins, an Upper Basin and a Lower Basin. The 1922 Compact negotiators left the task of allocating water to individual states to future negotiations among the sub-basins. The five states with Upper Basin lands completed this task in 1948. The negotiations of the Upper Colorado River Basin Compact provide significant context for understanding the Law of the River, particularly considering ongoing Post-2026 Colorado River Operations discussions.

This article examines the dynamics between the states, the role of the United States, the debate over how to measure beneficial consumptive use and the decision to utilize the Stream Depletion Theory, and tribal water allocations with an eye towards the future implications of these frameworks.