Aug 16 2022Share

A Tier 2a Shortage is confirmed, but uncertainty remains

By Warren Tenney

What does a Tier 2a Shortage mean?

The US Bureau of Reclamation declared a Tier 2a Shortage for the Colorado River in 2023 with its August 24-Month Study publication. Under the current framework for managing the River, the August 24-Month Study determines what level of shortage the River will be in based on the projected levels of Lake Mead for January of the following year. The Tier 2a Shortage determines that central Arizona will receive 592,000 acre-feet less Colorado River water in 2023, which means an additional 80,000 acre-feet will be cut compared to this year's Tier 1 Shortage. 

In comparison, here are the prescribed cutbacks in a Tier 2a Shortage:

  • Arizona: 592,000 acre-feet, which is approximately 21% of the state's annual apportionment
  • Nevada: 25,000 acre-feet, which is 8% of the state's annual apportionment
  • Mexico: 104,000 acre-feet, which is approximately 7% of the country's annual allotment
  • California: There is no required water savings contribution for California in 2023

Why is more than a Tier 2a Shortage needed?

In addition to declaring the Tier 2a Shortage, Reclamation reiterated that even further reductions will be needed in 2023 since the current framework is not doing enough to protect the River. In other words, the Tier 2a Shortage Declaration is a formality that does not encompass the extent of reductions necessary to prevent the Colorado River system from reaching critical levels in Lake Mead and Lake Powell.

In June, the Commissioner said water usage in the Basin had to be reduced by 2 to 4 million acre-feet in 2023. The seven Basin States – Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming – were tasked with developing a plan within 60 days to accomplish this drastic reduction for a River currently producing less than 13 million acre-feet of water.

Unfortunately, the States failed to produce a viable plan by the deadline. Reclamation has granted the Basin States an unspecified amount of time to continue negotiating and see if they can overcome provincial self-interests and develop a wholistic approach for protecting the River for all users.

Now, we continue to wait and see if the States can devise such a plan. Ultimately, Reclamation must fulfill its leadership responsibilities and determine what actions must be taken to prevent the Colorado River system from reaching such low levels that water is unable to pass through Hoover or Glen Canyon Dams. 

How have the cities prepared for a Tier 2a Shortage?

Even after investing billions in treatment plants and infrastructure to utilize Colorado River water, the ten AMWUA cities have been preparing for years to receive less water from the River. These preparations have been based on the framework established for operating Lake Mead and Lake Powell, known as the 2007 Interim Guidelines and the 2019 Drought Contingency Plan (DCP). These guidelines include the Tier 1, Tier 2, and Tier 3 shortage levels, which would intentionally leave water in Lake Mead to keep water levels from reaching those critical levels that are now closer to becoming a reality.

Each city is prepared for Tier 2 and even Tier 3 shortages because they have invested in diverse and reliable water portfolios, funded infrastructure and technology, stored water underground, instilled a conservation ethic, and have drought and shortage preparedness plans. In addition, the cities, along with other stakeholders, have helped Arizona make significant contributions to leave water in Lake Mead and stave off shortages for as long as possible. These proactive measures and long-term planning efforts are necessary in our arid state and have ensured reliable water supplies during times of drought and shortage.

Reclamation says more cuts are needed. What impact will those additional reductions have on the cities?

The immediate challenge is the unpredictability of what additional reductions beyond a Tier 2a Shortage will be placed on water providers for 2023. Municipal water providers face operational challenges with their treatment plants and delivery systems without knowing how significant a cutback will be required from their Colorado River water supply. These challenges include determining how to move their other water supplies – groundwater and Salt and Verde River water - to ensure the reliability of their systems. These adjustments require time for planning, stretching their existing workforce, and a significant amount of money from already set budgets for 2023.

Despite the speed at which the River has declined and with the real possibility of having significantly less water next year, the ten AMWUA cities are up to the task of meeting the water demands of their communities.

What needs to happen next?

The ten AMWUA cities will continue to plan and prepare even amidst uncertainty while waiting for Reclamation to make a decision. 

Reclamation and state leaders must pursue a more long-term sustainable approach to managing the Colorado River rather than trying to make marginal cuts that barely help avert shortage from year to year. Reclamation needs to take definitive action to reduce River demands throughout the Basin. Every water user in all sectors within each state must be a part of the solution by contributing to the protection of this shared river system. Otherwise, Colorado River conditions will rapidly spiral towards deadpool, and there will not be a River to manage. Decreasing the River's demand today will protect the River's future, benefiting everyone. This is especially true for municipal water providers, who need greater precision of what to expect from such an important water supply as they continue to make critical management decisions that will impact millions of residents and future generations. 

A statement from ADWR Director Tom Buschatzke and CAP General Manager Ted Cooke in response to the U.S. Department of the Interior announcement of actions to protect the Colorado River system and 2023 Operating Conditions for Lake Powell and Lake Mead is available HERE.

For over 50 years, the Arizona Municipal Water Users Association has worked to protect our member cities' ability to provide their communities with assured, safe, and sustainable water supplies. For more water information, visit

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