River
Compacts
As the water supplies in the West became more intensively used in the early part of the twentieth century, the “water wars” began. As a result, western water law evolved through a series of legislative as well as court-related actions. Many of the issues were local in nature; however, they also evolved into interstate and eventually international issues. A great amount of attention focused on the Colorado River because it is one of the most heavily used rivers for multipurpose activities. The Upper Basin states, where the water originates, include Utah, Colorado, Wyoming, and New Mexico. These states used water for agricultural as well as industrial purposes but did not fully use all the water in the river. As the water flowed through Arizona, the southern tip of Nevada, and California (the Lower Basin states), entrepreneurial interests found that they could make the arid climate very productive by diverting water from the Colorado River for irrigation and by rotating crops. Also, large municipal areas such as Los Angeles and San Diego developed in southern California. As the Upper Basin states started to use more water, thereby reducing the water flowing downriver to the Lower Basin states, great debate began in the national Congress. These debates culminated in the Colorado River Compact, which was signed in 1922. The Compact split the water 50-50 between the Upper Basin states and the Lower Basin states. At that time, hydrologists estimated that the Colorado River would produce about 15 million acre feet of water in an average year, therefore 7.5 million acre feet were allocated to the Upper Basin states and 7.5 million acre feet were allocated to the Lower Basin states. Lee’s Ferry was designated as the measuring point for this compact. In 1956, the Colorado River Storage Project (CRSP) was initiated to provide storage facilities for the Upper Basin states so that they could meet the Compact needs.
As the irrigation in Arizona and California increased, and especially with the increase in fertilization to maximize crop production, the quantity of water going to Mexico decreased and the mineral content of this water increased. The Mexican government raised concern about the issues, and eventually the United States and Mexico entered into a compact on the quantity and quality of water flowing to Mexico.
