Yuma Ag and You: The Law of the River

Bobbi Stevenson-McDermott     Dec. 25, 2017 publication

Last week, the Yuma Area Agricultural Committee held another of their new legislator tours to acquaint newly elected state representatives and senators to the agricultural wonder and value to Arizona of Yuma’s agricultural industry. It is always amazing to listen to the comments of participants as they quote information they have read or seen on media, but never experienced. One of the first lessons often is the Law of the River.

The Colorado River water rights that Yuma County water associations and irrigation districts hold are some of the oldest on the River. Water short areas of Arizona, California and Nevada particularly look constantly for ways to put their straws into our water.

The Colorado River is managed and operated under numerous compacts, federal laws, court decisions and decrees, contracts and regulatory guidelines collectively known as the Law of the River. This collection of documents apportions the water and regulates the use and management of the Colorado River among the 7 basin states and Mexico.

The Colorado River Compact of 1922 is the cornerstone of the law of the river and was negotiated by the 7 basin states and the federal government in 1922. It defined the relationship between the upper basin states, where most of the river’s water supply originates and the lower basin where most of the water demands were developing. At the time, the upper basin states were concerned that plans for Hoover Dam and other water development projects in the lower basin would, under Western water law doctrine of prior appropriation, deprive them of their ability to use the river flows in the future.

The Boulder Canyon Project of 1928 allowed the construction of Hoover Dam and related irrigation facilities in the lower basin and divided the lower basins portion of water between Arizona, California and Nevada. The California Seven Party Agreement of 1931 helped settle the longstanding conflict between California agricultural and municipal interests over Colorado River water priorities. The seven principal claimants were: the Palo Verde Irrigation District, CA; Yuma Project, AZ; Imperial Irrigation District, CA; Coachella Valley Irrigation District, CA; Metropolitan Water District, CA; and the city and county of San Diego, CA. They achieved consensus on the amounts of water allocated on an annual basis to each entity. While this did not resolve all the issues, the wording was incorporated into the major California Delivery contracts for water.

The Mexican Water Treaty of 1944 committed 1.5 million acre feet annually to Mexico. The amount of water delivered only counts for treaty purposes when it is ordered by Mexico. Flood flows on the Colorado and Gila Rivers do not count as treaty credit.

The Upper Basin Compact of 1948 created the Upper Colorado River Commission and apportioned the 7.5 million acre feet of water between Colorado, New Mexico, Utah and Wyoming.

In addition to these compacts, there were the Colorado River Storage Project Act of 1956 allowing the construction of Glen Canyon, Flaming Gorge; Navajo and Curecanti Dams for river regulation, power production, irrigation and other uses. The Arizona V California Supreme Court Decision of 1964 settled a 25 year old dispute between Arizona and California which involved the building of the Central Arizona Project so that Arizona could use its full allotment of Colorado River Water. The Central Arizona Project which carries Colorado River water to central and southern Arizona is the most junior water right on the river.

Since 1964 there have been 6 additional documents which affect Colorado River operations. The 688 miles of the Colorado River are managed by the Lower Colorado Region Office of the Bureau of Reclamation located in Yuma. You can understand why the water users on the Colorado River often say: Whiskey is for drinking and Water is for fighting!