Following the conclusion of World War II, Arizona’s focus returned to a critical issue for its burgeoning development: water. The 1940s proved to be a pivotal decade, marked by federal legislation that significantly shaped the state’s long-term water resources. Among these landmark decisions was the Mexican Water Treaty of 1944, a crucial agreement that guaranteed Mexico an annual allocation of water from the Colorado River, known as “mexican water”. This treaty not only had international implications but also played a vital role in the ongoing narrative of water rights and distribution in the American Southwest.
The Mexican Water Treaty: Defining “Mexican Water” Allocation
The Mexican Water Treaty, officially signed in 1944, was a landmark agreement between the United States and Mexico concerning the utilization of waters from the Colorado River and other sources like the Rio Grande and Tijuana River. Crucially, this treaty formalized the allocation of 1.5 million acre-feet of Colorado River water annually to Mexico. This allocation, often referred to as “mexican water”, aimed to provide a reliable water supply for Mexico, particularly for agricultural and municipal use in the Mexicali Valley and other regions bordering the Colorado River. The treaty also included provisions for adjusting water deliveries based on specific circumstances, acknowledging the fluctuating nature of water resources in the arid region.
Arizona’s Colorado River Compact and the Quest for Water Security
Simultaneously, Arizona was actively solidifying its own water rights within the United States. In 1944, the state finally ratified the Colorado River Compact of 1922. This ratification was a significant step, allowing Arizona to contract with the Secretary of the Interior for an annual delivery of 2.8 million acre-feet of Colorado River water. This move underscored Arizona’s determination to secure its water future and leverage the Colorado River as a primary water source.
Building on these developments, just three years later, Arizona initiated efforts to authorize the Central Arizona Project (CAP). This ambitious project, designed to address Arizona’s critical water shortage and alleviate power shortages in the Southwest, was deemed economically viable by Secretary Krug in a Department of the Interior report submitted to Congress in late September 1948. The projected benefits of CAP were estimated to surpass its substantial $738 million cost by a significant margin.
Secretary Krug emphasized the importance of Arizona’s water claims in his transmittal letter, stating that the project’s feasibility was predicated “upon the assumption that the claims of the state of Arizona to this water are valid.” However, despite the promising report, California’s opposition stalled the proposal, delaying the resolution of Arizona’s Colorado River water claims and the fate of the Central Arizona Project for two decades.
The Upper Colorado River Basin Compact: Further Defining Arizona’s Water Share
Adding another layer to the complex water rights landscape, Arizona, along with Colorado, New Mexico, Utah, and Wyoming, signed the Upper Colorado River Basin Compact on October 11, 1948. This compact granted Arizona an additional 50,000 acre-feet of Colorado River water from the Upper Basin. Furthermore, it established the Upper Colorado River Commission, a body tasked with managing water resources in the Upper Basin states.
Conclusion: The Enduring Legacy of “Mexican Water” and Arizona’s Water Strategy
The 1940s were a transformative period for Arizona’s water management. The Mexican Water Treaty established the concept of “mexican water” allocation from the Colorado River, recognizing Mexico’s legitimate water needs. Simultaneously, Arizona solidified its own rights through the Colorado River Compacts and initiated the vision for the Central Arizona Project. While challenges and disputes persisted, particularly with California, these foundational agreements laid the groundwork for the future of water resource management in Arizona and the broader Southwest, inextricably linked with the international dimension of “mexican water” and the Colorado River.
