Arizona’s Water Woes

By Matthew Adler.

On October 1, 2021, Arizona lost 18% of its annual Colorado River water allocation. This cut, amounting to 512,000 acre-feet of water per year (equivalent to over 150 billion gallons), is a result of the Department of the Interior’s recent declaration of a water shortage on the Colorado River. The declaration followed a projection by the Bureau of Reclamation that water levels in Lake Mead will, for the first time ever, fall below 1,075 feet within the next two years. As of now, the shortage declaration only affects the lower basin states of Arizona, Nevada, and California, as well as the country of Mexico. However, a similar shortage declaration for the upper basin states may be on the horizon.

Inequity Between the States

This dire projection implicates a variety of water management agreements, primary among them being the 2019 Drought Contingency Plan and the 2007 Interim Shortage Guidelines. These two agreements create a schedule of cuts that become increasingly onerous as water levels in the major reservoirs continue to drop. The recent shortage declaration places the lower basin in Tier 1, the first of seven such tiers. In Tier 1, Arizona is forced to curtail its Colorado River water usage by 18%, while Nevada must shoulder cuts of 7%. California, on the other hand, takes no cuts at all. In fact, California is not required to give up a single drop of water until a Tier 3 shortage is declared. This inequitable state of affairs is a result of the senior status of California’s water rights, which the state was able to secure in exchange for supporting the construction of Arizona’s elaborate and expensive network of canals known as the Central Arizona Project.

Tension between Arizona and California over water rights is nothing new. Indeed, Arizona went to war with California in 1934 as a result of disagreements over Colorado River management. In that year, the Bureau of Reclamation began constructing the Parker Dam in order to supply Southern California with the water it needed to support its growing population. Arizona Governor Benjamin Moeur, who had opposed the project from the beginning, felt that California was attempting to steal water in violation of a 1922 interstate compact. Upon the commencement of construction, and seeing no alternative, Governor Moeur declared martial law and dispatched the Arizona National Guard to halt construction of the dam. The Guard sailed up the river on steamboats, thus constituting Arizona’s navy. The owner of the steamboats, a local woman named Nellie T. Bush, was dubbed the admiral of Arizona’s navy. This “war” ended in ignominious defeat for Arizona without the firing of a single shot. After a brief delay, construction on the dam resumed, and today we have Lake Havasu as a result.

What Now?

Returning to the present, there is no question that Arizona’s current water situation is perilous. Because Arizona also draws water from other minor rivers and from groundwater, the 18% cut to the state’s Colorado River water allocation amounts to an 8% cut to the state’s total water usage. Obviously, such a severe cut is inconsistent with a continuation of business as usual. There are two things that Arizona must do. First, Arizona must take unilateral steps to become more sustainable in its water use. Second, Arizona must return to the negotiating table to hammer out a new water agreement with the various interested parties, including California, Nevada, New Mexico, Colorado, Utah, Wyoming, Mexico, the U.S. government, and numerous tribal governments.

Due to their low-priority rights, farmers in Pinal County will bear the brunt of the Arizona water cuts. The state is pursuing a variety of short-term measures to alleviate the pain suffered by these farmers, including pumping more groundwater, drilling new wells, paying the farmers to fallow their fields, and providing the farmers with water sourced from other users who have voluntarily agreed to forego use of the water. However, these measures will not be enough in the long term. First, there simply is not enough groundwater that can be safely and legally withdrawn to support continued farming and development in Pinal County. Second, if Arizona’s Colorado River allocation continues to shrink, then the water being provided to these farmers as mitigation will dry up as well. Eventually, Arizona will need to restructure its agricultural industry in a more fundamental way, shifting from water-intensive crops to desert-appropriate crops. After all, agriculture is responsible for around 70% of all water usage in the region. Arizona must also find a way to encourage both farmers and non-farmers to adopt more efficient irrigation technology, rather than making use of wasteful practices such as flood irrigation. As the law currently stands, farmers are often hesitant to adopt new technology out of fear that reduced water usage will result in forfeiture of the right to that water.

Arizona must also return to the negotiating table with its sister states, as well as with Mexico and numerous sovereign tribes. The tribes, often neglected, are a crucial component of any agreement. When combined, tribes hold the rights to about 25% of the water in the Colorado River. As water levels continue to fall, the federal government will require the states to engage in additional contingency planning, but it is anyone’s guess as to what those plans will look like. One creative and promising, but likely quite costly, idea that Arizona is pursuing is financing desalination plants in Mexico in exchange for some of Mexico’s Colorado River water allocation.


As the western United States continues to grow, it will become increasingly imperative to formulate a cooperative and sustainable water management plan both within and among the several states. However, if it does come to war, Arizonans can rest assured that California’s enduring unpopularity will engender no shortage of allies.

"Lake Mead" by Colin Davis Studio is licensed under CC BY-NC 2.0